Low lignin plant biomass-derived cellulose nanofibrils

Abstract

A method of producing cellulose nanofibrils from low-lignin plant biomass is provided (110), in which the biomass is contacted with an aqueous medium (120) to deconstruct the biomass and form a cellulose-rich fraction, the cellulose-rich fraction is separated from the deconstructed biomass (130), and the cellulose-rich fraction is mechanically processed in water (140) to form cellulose nanofibrils. The cellulose nanofibrils may form nanocellulose networks that are provided as aqueous gels or densified sheets. A plant growth substrate is also provided, comprising an aqueous nanocellulose gel including water and cellulose nanofibrils dispersed therein, the cellulose nanofibrils being obtainable by the method, and the substrate being configured for use in plant cultivation with improved water-retention and post-harvest freshness characteristics.

Description

Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1LOW LIGNIN PLANT BIOMASS-DERIVED CELLULOSE NANOFIBRILSTECHNICAL FIELD

[0001] The subject matter disclosed herein relates to methods for producing cellulose nanofibrils from plant biomass and nanocellulose networks derived therefrom.BACKGROUND

[0002] In recent years, there has been growing interest in using natural biomaterials to reduce reliance on finite fossil-derived resources and to address concerns related to persistence and environmental accumulation of synthetic polymers. Cellulose, the most abundant biopolymer on Earth, is a central focus in this effort. Cellulose is present in a wide variety of plant-derived feedstocks, including wood, agricultural residues, and food-processing byproducts such as mesocarps, skins, and pomace.

[0003] A variety of processes have been developed to produce nanocellulose from lignocellulosic feedstocks. Many such processes begin from wood pulps or other highly lignified materials and employ combinations of high-temperature water treatment, chemical pulping, and bleaching to remove hemicellulose and lignin prior to nanoscale fibrillation. Autohydrolysis approaches, for example, may utilize hot water at elevated temperatures to hydrolyze hemicellulose into soluble fragments that can be removed from the fiber matrix. Mechanical nanofibrillation is often carried out using high-pressure homogenization, microfluidization, grinding, or intensive ultrasonication, which can require substantial energy input, especially when starting from fibers that are relatively stiff, long, and strongly bound by lignin. While these approaches can yield functional nanocellulose, they often involve complex equipment, elevated temperatures, and intensive chemical usage.SUMMARY

[0004] A method of producing cellulose nanofibrils from plant biomass, comprising providing a plant biomass having less than 15 wt% lignin; contacting the plant biomass with an aqueous medium at a temperature in a range of 20-100 °C to produce a deconstructed plant biomass and a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed plantClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1biomass; and mechanically processing the cellulose-rich fraction to form cellulose nanofibrils having an average diameter in a range of 2-200 nm.

[0005] A plant growth substrate comprising an aqueous nanocellulose gel, the nanocellulose gel comprising water and cellulose nanofibrils having an average diameter in a range of 2-200 nm dispersed therein, the cellulose nanofibrils being obtainable by a method comprising providing a plant biomass having less than 15 wt% lignin; contacting the plant biomass with an aqueous medium comprising water at a temperature in a range of 20-100 °C to deconstruct the biomass and form a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed biomass; and processing the cellulose-rich fraction in water to produce the cellulose nanofibrils.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] This written disclosure describes illustrative embodiments that are non-limiting and non-exhaustive. Reference is made to illustrative embodiments that are depicted in the figures, in which:

[0007] FIG. 1 illustrates a flowchart showing method 100 for producing cellulose nanofibrils from plant biomass, according to some embodiments.

[0008] FIG.2A illustrates images of date (left), carrot (middle), and watermelon (right) tissues before contacting with an aqueous medium, according to some embodiments.

[0009] FIG.2B illustrates images of date (left), carrot (middle), and watermelon (right) tissues after contacting with an aqueous medium, according to some embodiments.

[0010] FIG.3 A illustrates images of a watermelon tissue before (left) and after (right) contacting with an aqueous medium, according to some embodiments.

[0011] FIG.3B illustrates images of a carrot tissue before (left) and after (right) contacting with an aqueous medium, according to some embodiments.

[0012] FIG.4 illustrates images of cellulose nanofibrils in the form of an aqueous gel made from the tissue of various plant biomasses, according to some embodiments.

[0013] FIG. 5 illustrates a chart showing comparative % yields following hydrothermal treatment and processing steps using various plant biomasses, according to some embodiments.

[0014] FIG.6A illustrates an image of a nanocellulose gel derived from pineapple tissue used as substrates for growing mustard microgreens, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0015] FIG.6B illustrates an image of nanocellulose gel derived from pineapple tissue used as substrates for growing mustard microgreens, according to some embodiments.

[0016] FIG.6C illustrates an image of nanocellulose gel derived from pineapple tissue used as substrates for growing mustard microgreens, according to some embodiments.

[0017] FIG.6D illustrates an image of nanocellulose gel derived from pineapple tissue used as substrates for growing mustard microgreens, according to some embodiments.

[0018] FIGS. 7A illustrates an SEM image of carrot periderm following hydrothermal treatment, according to some embodiments.

[0019] FIG. 7B illustrates an SEM image of carrot periderm following hydrothermal treatment, according to some embodiments.

[0020] FIG. 8A illustrates an SEM image of watermelon mesocarp following hydrothermal treatment, according to some embodiments.

[0021] FIG. 8B illustrates an SEM image of watermelon mesocarp following hydrothermal treatment, according to some embodiments.

[0022] FIG.9A illustrates an SEM image of date fruit following hydrothermal treatment, according to some embodiments.

[0023] FIG.9B illustrates an SEM image of date fruit following hydrothermal treatment, according to some embodiments.

[0024] FIG.9C illustrates an SEM image of date fruit following hydrothermal treatment, according to some embodiments.

[0025] FIGS. 10A illustrates an SEM image of networks of cellulose nanofibrils derived from carrot periderm, according to some embodiments.

[0026] FIG. 10B illustrates an SEM image of networks of cellulose nanofibrils derived from carrot periderm, according to some embodiments.

[0027] FIG. 10C illustrates an SEM image of networks of cellulose nanofibrils derived from carrot periderm, according to some embodiments.

[0028] FIG. 10D illustrates an SEM image of networks of cellulose nanofibrils derived from carrot periderm, according to some embodiments.

[0029] FIGS. 11A illustrates an SEM image of networks of cellulose nanofibrils derived from carrot xylem, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0030] FIG. 11B illustrates an SEM image of networks of cellulose nanofibrils derived from carrot xylem, according to some embodiments.

[0031] FIG. 11C illustrates an SEM image of networks of cellulose nanofibrils derived from carrot xylem, according to some embodiments.

[0032] FIGS. 12A illustrates an SEM image of networks of cellulose nanofibrils derived from watermelon mesocarp, according to some embodiments.

[0033] FIG. 12B illustrates an SEM image of networks of cellulose nanofibrils derived from watermelon mesocarp, according to some embodiments.

[0034] FIG. 12C illustrates an SEM image of networks of cellulose nanofibrils derived from watermelon mesocarp, according to some embodiments.

[0035] FIG. 13 illustrates an SEM image of cellulose nanofibrils derived from pineapple tissue, according to some embodiments.

[0036] FIGS. 14A illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments.

[0037] FIG. 14B illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments

[0038] FIG. 14C illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments

[0039] FIG. 14D illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments

[0040] FIG. 14E illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments

[0041] FIG. 14F illustrates an SEM image of cellulose nanofibrils derived from various plant biomasses, according to some embodiments

[0042] FIG. 15 illustrates a chart showing average diameters of cellulose nanofibrils derived from various plant biomasses, according to some embodiments.

[0043] FIG. 16A illustrates a chart showing measured diameters of cellulose nanofibrils derived from date fruit, according to some embodiments.

[0044] FIG. 16B illustrates a chart showing measured diameters of cellulose nanofibrils derived from carrot xylem, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0045] FIG. 16C illustrates a chart showing measured diameters of cellulose nanofibrils derived from carrot periderm, according to some embodiments.

[0046] FIG. 16D illustrates a chart showing measured diameters of cellulose nanofibrils derived from watermelon mesocarp, according to some embodiments.

[0047] FIG. 16E illustrates a chart showing measured diameters of cellulose nanofibrils derived from watermelon pericarp, according to some embodiments.

[0048] FIG. 16F illustrates a chart showing measured diameters of cellulose nanofibrils derived from date pomace, according to some embodiments.

[0049] FIG. 17 illustrates an atomic force microscopy (AFM) image of four cellulose nanofibrils derived from watermelon mesocarp, according to some embodiments.

[0050] FIG. 18A illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp, according to some embodiments.

[0051] FIG. 18B illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp, according to some embodiments.

[0052] FIG. 18C illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp, according to some embodiments.

[0053] FIG. 18D illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp, according to some embodiments.

[0054] FIG. 19 illustrates six x-ray diffraction (XRD) spectra of cellulose nanofibrils derived from various plant biomasses, according to some embodiments.

[0055] FIG.20A illustrates an XRD spectrum of date fruit before and after processing, according to some embodiments.

[0056] FIG.20B illustrates an XRD spectrum of carrot xylem before and after processing, according to some embodiments.

[0057] FIG.20C illustrates an XRD spectrum of carrot periderm before and after processing, according to some embodiments.

[0058] FIG.20D illustrates an XRD spectrum of watermelon mesocarp before and after processing, according to some embodiments.

[0059] FIG.20E illustrates an XRD spectrum of watermelon pericarp before and after processing, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0060] FIG. 20F illustrates an XRD spectrum of date pomace before and after processing, according to some embodiments.

[0061] FIG. 21 A illustrates a graph showing gelling point concentrations of various nanocellulose gels, according to some embodiments.

[0062] FIG. 2 IB illustrates a chart showing gelling point % values of nanocellulose gels made from carrot xylem and carrot periderms, according to some embodiments.

[0063] FIG. 22 illustrates an image showing results of gelling point analysis of a nanocellulose gel derived from pineapple tissue, according to some embodiments.

[0064] FIG. 23A illustrates a UV-vis spectrum of CNDF, according to some embodiments.

[0065] FIG. 23B illustrates a UV-vis spectrum of CNCX, according to some embodiments.

[0066] FIG. 23C illustrates a UV-vis spectrum of CNCP, according to some embodiments.

[0067] FIG. 23D illustrates a UV-vis spectrum of CNWM, according to some embodiments.

[0068] FIG. 23E illustrates a UV-vis spectrum of CNWP, according to some embodiments.

[0069] FIG. 23F illustrates a UV-vis spectrum of CNDP, according to some embodiments.

[0070] FIG. 24A illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNDF, according to some embodiments.

[0071] FIG. 24B illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNCX, according to some embodiments.

[0072] FIG. 24C illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNCP, according to some embodiments.

[0073] FIG. 24D illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNWM, according to some embodiments.

[0074] FIG. 24E illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNWP, according to some embodiments.

[0075] FIG. 24F illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNDP, according to some embodiments.

[0076] FIG. 25A illustrates superimposed FTIR spectra of date fruit before and after processing, according to some embodiments.

[0077] FIG. 25B illustrates superimposed FTIR spectra of carrot xylem before and after processing, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0078] FIG.25C illustrates superimposed FTIR spectra of carrot periderm before and after processing, according to some embodiments.

[0079] FIG.25D illustrates superimposed FTIR spectra of watermelon mesocarp before and after processing, according to some embodiments.

[0080] FIG.25E illustrates superimposed FTIR spectra of watermelon pericarp before and after processing, according to some embodiments.

[0081] FIG.25F illustrates superimposed FTIR spectra of date pomace before and after processing, according to some embodiments.

[0082] FIG.26 illustrates six FTIR spectra of networks of cellulose nanofibrils derived from various plant biomasses according to some embodiments.

[0083] FIG.27A illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from DF samples, according to some embodiments.

[0084] FIG.27B illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from CX samples, according to some embodiments.

[0085] FIG.27C illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from CP samples, according to some embodiments.

[0086] FIG.27D illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from WM samples, according to some embodiments.

[0087] FIG.27E illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from WP samples, according to some embodiments.

[0088] FIG.27F illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from DP samples, according to some embodiments.

[0089] FIG.28A illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from DF samples, according to some embodiments.

[0090] FIG.28B illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from CX samples, according to some embodiments.

[0091] FIG.28C illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from CP samples, according to some embodiments.

[0092] FIG.28D illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from WM samples, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0093] FIG.28E illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from WP samples, according to some embodiments.

[0094] FIG.28F illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from DP samples, according to some embodiments.

[0095] FIG.29 illustrates a chart showing percentage drop of cellulose nanofibrils over time during sedimentation tests of various networks of cellulose nanofibrils, according to some embodiments.

[0096] FIG.30 illustrates images of sedimentation analysis of various networks of cellulose nanofibrils derived from various plant biomasses, according to some embodiments.

[0097] FIG.31 illustrates suspension stability results of pineapple tissue having been treated with various combinations of alkali treatment (AT), bleaching (BL), and processing (BL), according to some embodiments.

[0098] FIG.32 illustrates images showing results of comparative wilting analysis using conventional pulp substrates and nanocellulose gel derived from plant biomass, according to some embodiments.

[0099] FIG.33 illustrates images of nanocellulose sheets derived from various plant biomasses, according to some embodiments.

[0100] FIG. 34 illustrates an SEM image of a cross section of a nanocellulose sheet derived from watermelon mesocarp, according to some embodiments.

[0101] FIG. 35 illustrates an XRD spectrum of reference cellulose paper.

[0102] FIG. 36A illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNDF, according to some embodiments.

[0103] FIG. 36B illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNCX, according to some embodiments.

[0104] FIG. 36C illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNCP, according to some embodiments.

[0105] FIG. 36D illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNWM, according to some embodiments.

[0106] FIG. 36E illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNWP, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0107] FIG. 36F illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0108] FIG. 37A illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNDF, according to some embodiments.

[0109] FIG. 37B illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNCX, according to some embodiments.

[0110] FIG. 37C illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNCP, according to some embodiments.

[0111] FIG. 37D illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNWM, according to some embodiments.

[0112] FIG. 37E illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNWP, according to some embodiments.

[0113] FIG. 37F illustrates superimposed graphs showing representative tensile stress-strain response of a nanocellulose sheet derived from CNDP and a comparable wood sample, according to some embodiments.

[0114] FIG. 38A illustrates a graph showing ultimate tensile strength test results of nanocellulose sheets derived from various plant biomasses, according to some embodiments.

[0115] FIG. 38B illustrates a graph showing strain at failure test results of nanocellulose sheets derived from various plant biomasses, according to some embodiments.

[0116] FIG. 38C illustrates a graph showing elastic modulus test results of nanocellulose sheets derived from various plant biomasses, according to some embodiments.

[0117] FIG. 39A illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNDF, according to some embodiments.

[0118] FIG. 39B illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNCX, according to some embodiments.

[0119] FIG. 39C illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNCP, according to some embodiments.

[0120] FIG. 39D illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNWM, according to some embodiments.

[0121] FIG. 39E illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNWP, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0122] FIG. 39F illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0123] FIG. 40A illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNDF, according to some embodiments.

[0124] FIG. 40B illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNCX, according to some embodiments.

[0125] FIG. 40C illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNCP, according to some embodiments.

[0126] FIG. 40D illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNWM, according to some embodiments.

[0127] FIG. 40E illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNWP, according to some embodiments.

[0128] FIG. 40F illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0129] FIG. 41A illustrates an SEM image of the surface of date pomace-derived nanocellulose sheet prior to mechanical analysis, according to some embodiments.

[0130] FIG. 41B illustrates an SEM image of the surface of date pomace-derived nanocellulose sheet prior to mechanical analysis, according to some embodiments.

[0131] FIG. 42A illustrates an SEM image of the surface of date pomace-derived nanocellulose sheet after mechanical analysis, according to some embodiments.

[0132] FIG. 42B illustrates an SEM image of a cross section of date pomace-derived nanocellulose sheet after mechanical analysis, according to some embodiments.

[0133] FIG. 43A illustrates an SEM image of the surface of a nanocellulose sheet derived from watermelon mesocarp before mechanical testing, according to some embodiments.

[0134] FIG. 43B illustrates an SEM image of the surface of a nanocellulose sheet derived from watermelon mesocarp after mechanical testing, according to some embodiments.

[0135] FIG. 44A illustrates an SEM image of the surface of a nanocellulose sheet derived from date pomace before mechanical testing, according to some embodiments.

[0136] FIG. 44B illustrates an SEM image of the surface of a nanocellulose sheet derived from date pomace before mechanical testing, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0137] FIG. 44C illustrates an SEM image of a cross-section of a nanocellulose sheet derived from date pomace before mechanical testing, according to some embodiments.

[0138] FIG. 44D illustrates an SEM image of a cross-section of a nanocellulose sheet derived from date pomace before mechanical testing, according to some embodiments.

[0139] FIG. 44E illustrates an SEM image of a cross-section of a nanocellulose sheet derived from date pomace before mechanical testing, according to some embodiments.

[0140] FIGS.45A illustrates an SEM image of the surface of a nanocellulose sheet derived from date pomace after mechanical testing, according to some embodiments.

[0141] FIG. 45B illustrates an SEM image of a cross section of a nanocellulose sheet derived from date pomace after mechanical testing, according to some embodiments.DETAILED DESCRIPTION

[0142] The present disclosure provides methods for producing cellulose nanofibrils from low-lignin plant biomass in low cost, mild, and non-energy intensive manners. Among the suitable low-lignin plant biomass suitable for these methods are fruits, vegetables, and their processing residues such as mesocarps and pomace. Rather than relying on wood pulps, strong mineral acids, or high-pressure homogenization, the methods disclosed herein take advantage of the intrinsic fragility of non- woody plant tissues in that, in some embodiments, slightly heated water and simple low-energy mixing apparatuses are sufficient to deconstruct individual plant cells and liberate nanoscale cellulose fibrils into a continuous nanocellulose network. Process severity can be tuned to the resilience of the starting biomass, yet still operate within a mild aqueous window that preserves cellulose structure and avoids utilization of harsh chemicals. The resulting cellulose nanofibrils can be configured as shear-thinning, elastic-dominant gels or densified sheets with desirable mechanical and optical properties. Some embodiments may be used as high-performance, bio-based substrates for plant cultivation that are derived from food and agricultural waste streams and are configured to enhance water retention, support vigorous plant growth, and extend post-harvest freshness relative to conventional substrates. In some embodiments, nanocellulose sheets produced according to these methods are further configured for use in a variety of applications such as packaging, barrier layers, filtration media, or mechanically reinforced composites.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0143] FIG. 1 illustrates a flowchart of method 100 for producing cellulose nanofibrils from plant biomass having less than 15 wt% lignin. Method 100 includes the following steps: providing 110 plant biomass having less than 15 wt% lignin, contacting 120 the plant biomass with an aqueous medium comprising water at a temperature in a range of 20-100 °C to produce a deconstructed plant biomass and a cellulose-rich fraction, separating 130 the cellulose-rich fraction from the deconstructed plant biomass, and mechanically processing 140 the cellulose-rich fraction to form cellulose nanofibrils having an average diameter in a range of 2-200 nm.

[0144] Providing 110 plant biomass involves providing a plant biomass having less than 15 wt% lignin. In some embodiments, the plant biomass has less than 14 wt% lignin. In some embodiments, the plant biomass has less than 13 wt% lignin. In some embodiments, the plant biomass includes tissue of one or more fruits or vegetables. In some embodiments, biomass sources include, without limitation, carrot roots, watermelon, date fruits, pineapple, and combinations thereof. In some embodiments, fruit-derived biomass sources include one or more of pericarp, mesocarp, endocarp, peel, skin, rind, flesh, core, xylem, or pomace of one or more fruits. In some embodiments, vegetable-derived biomass sources include one or more of epidermis, periderm, cortex, pith, xylem, flesh, or pomace of one or more vegetables, including roots, tubers, stems, leaves, or inflorescences. In some embodiments, the plant biomass is obtained directly from fresh produce. In some embodiments, the biomass is obtained from waste streams, such as peels, mesocarps, trimmings, and pomace left over from juice, puree, or syrup production. Using such streams can reduce feedstock cost and promote valorization of agricultural byproducts. In some embodiments, the plant biomass comprises mostly parenchymatous tissue. This tissue may be characterized as having a majority of cells being water- rich storage parenchyma cells rather than highly lignified structural or vascular cells. In some embodiments, the plant biomass may comprise at least, equal to, or between any two of 70%, 80%, 90%, 95%, 99%, and 100% parenchymatous tissue taken as a proportion of all plant tissue.

[0145] In some embodiments, cross-sectional lumen size of individual cells can range from about 15 pm to about 320 pm, with thin cell walls and only minor lignification. Such tissues are more easily deconstructed into cellulose-rich fractions under mild conditions than highly lignified tissues, which often require intensive pulping. In some embodiments, the plant biomass is derived predominantly from tissues whose primary biological function is storage of water, soluble sugars, nutrients, and metabolites rather than long-term structural support, for example parenchymatousClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1tissues in fleshy fruits, roots, and tubers, as opposed to highly lignified structural or vascular tissues such as secondary xylem in wood. In some embodiments, the plant biomass has a lignin content (on a dry basis) of less than, equal to, or between any two of 25, 20, 18, 16, 15, 14, 13, 10, 5, 2, and 1 wt%. In some embodiments, the biomass is substantially lignin-free, with lignin present only as trace amounts associated with vascular traces or epidermal regions. These low-lignin characteristics allow cellulose nanofibrils to be produced using water and relatively low-energy processing, as opposed to high-pressure homogenization or strong mineral acid treatments.

[0146] In some embodiments, the biomass is comminuted prior to contacting 120, for example by shredding, chopping, grating, or coarse blending, to increase surface area and facilitate mass transfer of water and solubles. In some embodiments, comminution is sufficient to reduce the biomass from intact sheets or pieces to short fragments, for example decreasing a characteristic dimension from the centimeter range to a few. In some embodiments, the biomass is provided as whole pieces (for example, intact mesocarps or slices) and comminution occurs later during mechanically processing 140.

[0147] Contacting 120 plant biomass with an aqueous medium involves contacting the plant biomass with an aqueous medium comprising water at a temperature in a range of 20-100 °C to produce a deconstructed plant biomass and a cellulose-rich fraction. The aqueous medium can be, for example, deionized water, distilled water, tap water, or combinations thereof. In some embodiments, the aqueous medium consists essentially of water. In some embodiments, the aqueous medium further contains dissolved salts, buffering agents, or other additives, provided that these do not substantially inhibit deconstruction or subsequent fibrillation. In some embodiments, the aqueous medium is heated prior to or during contacting.

[0148] Water temperature during contacting can be at least, equal to, or between any two of 20, 40, 60, 70, 80, 90, 95, and 100 °C. In some embodiments, the biomass is boiled in water at or near 100 °C for at least, equal to, or between any two of 10, 20, 30, 60, and 120 minutes per cycle. In some embodiments, lower temperatures such as 60-90 °C are used for extended periods, for example at least, equal to, or between any two of 30, 60, 120, and 240 minutes. The timetemperature combination is selected based on the mechanical resilience and composition of the particular produce.

[0149] The mass ratio of water to biomass can be adjusted to facilitate efficient washing and deconstruction. In some embodiments, a water: biomass mass ratio is at least, equal to, or betweenClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1any two of 2:1, 5:1, 10:1, 20:1, and 50:1. Higher ratios can enhance removal of soluble components (e.g., sugars, organic acids, pigments, and phenolics) while lower ratios can conserve water. Contacting 120 can be carried out in batch vessels or continuous reactors. In some embodiments, the biomass is immersed in water and heated under atmospheric pressure with intermittent or continuous stirring.

[0150] In some embodiments, contacting 120 includes multiple washing cycles in fresh water to gradually remove non-cellulosic solubles. In some embodiments, intermediate decanting steps are performed to discard colored or turbid supernatant containing solubilized pectin, sugars, and phenolic compounds, while retaining the solid fraction enriched in cellulose. In some embodiments, contacting 120 alone, without added alkali or oxidizing agents, is sufficient to soften and partially deconstruct the biomass, especially for carrot and watermelon tissues. Following contacting 120, plant biomass cells of certain types may exhibit swollen and opened cells with thin walls and early nanofibrillar features.

[0151] Separating 130 involves separating the cellulose-rich fraction from the deconstructed plant biomass. After contacting 120, the biomass typically consists of softened, partially deconstructed solids suspended in an aqueous phase containing dissolved and colloidally dispersed non-cellulosic components. Separating 130 isolates a cellulose-rich fraction that can be subsequently fibrillated into cellulose nanofibrils. In some embodiments, separating 130 comprises centrifuging the deconstructed biomass to obtain the cellulose-rich fraction. Centrifugation can be performed at rotational speeds that are at least, equal to, or between any two of 1000, 3000, 5000, 7000, and 10000 rpm for times that are at least, equal to, or between any two of 5, 10, 15, 30, and 60 minutes. The denser cellulose-rich fraction may form a gel-like sediment, while the supernatant contains water soluble compounds, including but not limited to sugars, organic acids, pigments, and residual fines. In particular, phenolic and carotenoid species may be substantially removed as part of the supernatant during separating 130.

[0152] In some embodiments, centrifugation is carried out multiple times, with intermediate decanting of the supernatant and redispersion of the sedimented solids in fresh water, to further purify the cellulose-rich fraction. In some embodiments, such downstream purification steps substantially reduce the concentration of soluble and colloidally dispersed non-cellulosic components (for example sugars, organic acids, phenolic compounds, pigments, and low-molecular-weight polysaccharides) in the cellulose-rich fraction, for example by at least, equal to,Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1or between any two of about 20, 40, 60, 80, and 90% relative to the initial suspension, thereby increasing the relative cellulose content and improving the grade of the resulting nanocellulose formulations. In some embodiments, separation can be carried out by alternative techniques, such as filtration through porous membranes, gravity settling followed by decanting, or a combination thereof. In some embodiments, coarse solids are removed by sieving prior to centrifugation. In some embodiments, separating 130 optionally includes one or more downstream purification steps and produces a cellulose- rich fraction with substantially reduced amounts of soluble non-cellulosic materials and an increased relative cellulose content.

[0153] In some embodiments, contacting 120 and separating 130 are repeated one or more times prior to mechanically processing 140. For example, in some embodiments, contacting 120 and separating 130 are repeated at least, equal to, or between any two of 2, 3, 4, and 5 cycles. In some embodiments, three cycles are used, corresponding to the repetition described in certain method claims.

[0154] Mechanically processing 140 involves processing the cellulose-rich fraction to form cellulose nanofibrils having an average diameter of at least, equal to, or between any two of 2, 4, 6, 8, 10, 20, 30, 40, 50, 100, 150, or 200 nm. The cellulose-rich fraction obtained after separation 130 can be a gel-like mass or a hydrated sediment. In some embodiments, mechanically processing 140 includes mechanical fibrillation using low-energy equipment such as kitchen blenders, rotorstator mixers, or laboratory-scale dispersers. In some embodiments, mechanically processing 140 is performed for at least, equal to, or between any two of 1, 3, 5, 10, 20, and 30 minutes. In some embodiments, mechanically processing 140 is performed in multiple cycles with cooling intervals to avoid excessive heating. In some embodiments, mechanically processing 140 includes more intensive mechanical treatments such as ball milling or higher-shear blending. These intensive treatments may be particularly useful for plant biomass that has undergone alkali and / or bleach treatment. In some embodiments, such higher-intensity treatments are used selectively to optimize fibrillation while balancing energy consumption and cost.

[0155] In some embodiments, mechanically processing 140 is carried out in water at a solids content that is at least, equal to, or between any two of 0.4, 0.5, 1.0, 2.0, 3.0, and 5.0 wt%. Lower solids can facilitate flow and energy- efficient fibrillation, while higher solids can increase process throughput. The resulting cellulose nanofibrils can be visually observed as making up a viscousClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1gel with distinct coloration depending on the source biomass (e.g., orange-tinted gels from carrots, greenish from watermelon mesocarps, brownish from date-derived fibers).

[0156] In some embodiments, mechanically processing 140 is configured to maintain cellulose primarily in the cellulose I allomorph, with little or no conversion to cellulose II. In some embodiments, XRD spectra of cellulose nanofibrils exhibit three main peaks at about 20 ~ 16.3°, 22.3°, and 34.8°, corresponding to the (110), (200), and (004) crystalline planes typical of cellulose I. The crystallinity index (CrI) of cellulose nanofibrils obtained from six non-wood sources ranges from about 36.1% to about 62.8%, indicating that the methods remove amorphous constituents while preserving crystalline cellulose.

[0157] In some embodiments, method 100 further comprises dispersing 150 the nanocellulose network in water to form a nanocellulose gel. In practice, mechanically processing 140 frequently yields a hydrated network directly. However, in some embodiments, the initially formed network is re-dispersed into water at a target solid content to standardize gel properties, for example at solids contents that are at least, equal to, or between any two of about 0.5, 1.0, 1.5, and 2.0 wt%, and in some embodiments typically in a range of about 1.0-2.0 wt%. Dispersing 150 can include adding the network to water, agitating (e.g., with a mixer or stirrer), and optionally sonicating to ensure uniform distribution. Nanocellulose gels prepared this way can exhibit gel points at solids concentrations that are at least, equal to, or between any two of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.5, 2.0, and 2.5 wt%. In some embodiments, the gel point is determined by a tube inversion assay, in which a gel at its gel point remains self-supporting when the tube is inverted. In some embodiments, the process is configured such that nanocellulose gels are self-supporting at solids contents at or below about 2.0 wt% in a tube inversion assay, which is indicative of a high degree of nanofibrillation.

[0158] In some embodiments, method 100 further includes depositing 160, which involves depositing the nanocellulose network onto a substrate. In some embodiments, depositing 160 comprises filtering a nanocellulose gel through a porous support such as a PVDF membrane, filter paper, or other porous substrate using vacuum filtration or gravity-driven filtration.

[0159] In some embodiments, method 100 further includes drying 170, which involves drying the deposited network to form a nanocellulose sheet. Drying 170 can be performed at room temperature, at an elevated temperature below the degradation temperature of cellulose (e.g., 30-100 °C), or under reduced pressure. Drying times can be at least, equal to, or between any two ofClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT12, 4, 8, 12, and 24 hours depending on thickness and conditions. In some embodiments, method 100 further comprises pressing the deposited nanocellulose network prior to or during drying. In some embodiments, wet or semi-dried sheets are hot-pressed at temperatures that are at least, equal to, or between any two of 60, 80, 100, and 120 °C for at least, equal to, or between any two of 0.5, 1, 2, 5, and 10 minutes under pressure. For example, sheets hot-pressed at about 80 °C for about 2 minutes yielded smooth surfaces and uniform thickness suitable for mechanical testing. Hot pressing can densify the network, reduce surface roughness, and improve inter-fibrillar bonding, thereby increasing mechanical strength.

[0160] In some embodiments, method 100 further includes alkali washing 180, which involves alkali washing the plant biomass prior to contacting 120. In some embodiments, alkali washing 180 is particularly advantageous for more resilient biomass such as pineapple mesocarps. Alkali washing 180 can include soaking the biomass in an aqueous alkali solution (e.g., sodium hydroxide) at a concentration that is at least, equal to, or between any two of 1, 2, 4, and 8 wt% NaOH, for a duration that is at least, equal to, or between any two of 1, 12, 24, 48, and 72 hours at a temperature that is at least, equal to, or between any two of 20, 40, and 60 °C. Following alkali treatment, the fibers are typically washed with water until neutral pH is reached, thereby removing residual alkali and solubilized components such as hemicellulose and lignin fragments. Alkali washing can reduce resistance to shredding or blending and can facilitate subsequent fibrillation, as evidenced by pineapple fibers that become more amenable to mechanical processing after sodium hydroxide treatment. In some embodiments, alkali washing also increases the ability of derived cellulose network-based substrates to support plant growth.

[0161] In some embodiments, method 100 further includes bleaching 190, which involves bleaching the plant biomass prior to contacting 120. In some embodiments, bleaching 190 is done after alkali washing 180. Bleaching 190 can include treating the alkali-washed fibers with an oxidizing agent, such as hydrogen peroxide, at a concentration that is at least, equal to, or between any two of 1, 3, 5, and 10 wt% H2O2, at a temperature that is at least, equal to, or between any two of 60, 70, 80, and 90 °C, for a time that is at least, equal to, or between any two of 0.5, 1, 2, and 4 hours. Bleaching 190 can further reduce residual chromophores, lignin, and hemicellulose, improving fiber brightness and, in some cases, enhancing fibrillation. In some embodiments, alkali washing alone is sufficient to yield high-performing substrates for plant growth, and bleaching isClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1omited to reduce costs and chemical usage. In some embodiments, method 100 includes one or more alkali washing 180 and bleaching 190 the plant biomass.

[0162] Method 100 is not limited to a single sequence of steps. In some embodiments, the core operations of providing 110, contacting 120, separating 130, and mechanically processing 140 are carried out once in that order. In some embodiments, contacting 120 and separating 130 are carried out in two or more contacting / separating cycles prior to mechanically processing 140, such that providing 110 is followed by a plurality of 120 / 130 cycles and at least one separating 130 of a cellulose-rich fraction precedes mechanically processing 140 of that cellulose-rich fraction. In addition to separating 130, which separates the cellulose-rich fraction from the deconstructed plant biomass produced by contacting 120, other separating operations can be performed before, between, or after any of the core operations. For example, coarse solids may be removed from the plant biomass before or during providing 110, and water or other liquids may be removed from nanocellulose gels or sheets after mechanically processing 140. In some embodiments, alkali washing 180 and bleaching 190 are carried out on the plant biomass before any contacting 120. In some embodiments, alkali washing 180 and / or bleaching 190 are carried out between two contacting 120 operations or between a contacting 120 and a subsequent separating 130. In some embodiments, alkali washing 180 and / or bleaching 190 are carried out after at least one separating 130 on the cellulose-rich fraction prior to mechanically processing 140.

[0163] In some embodiments, dispersing 150 to form a gel, depositing 160 on a substrate, pressing, and drying are performed after mechanically processing 140 and are implemented as online operations in a continuous process, while in other embodiments one or more of these optional downstream steps are carried out as discrete batch operations. In typical implementations, however, providing 110 is followed by at least one instance of contacting 120, at least one instance of separating 130 the cellulose-rich fraction produced by contacting 120, and mechanically processing 140 of that cellulose-rich fraction, because providing a low-lignin plant biomass and then deconstructing and isolating a cellulose-rich fraction in this sequence facilitates formation of cellulose nanofibrils with the desired morphology and properties.

[0164] The present disclosure provides cellulose nanofibrils having an average diameter in a range of 2-200 nm, obtainable by methods including providing plant biomass having less than 15 wt% lignin, contacting the biomass with an aqueous medium at 20-100 °C to form a cellulose-rich fraction, separating the cellulose-rich fraction, and processing the fraction in water to produce theClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1network. In some embodiments, the cellulose nanofibrils are provided as a highly entangled fibrous network called a nanocellulose network observable under SEM or AFM, with fibrils forming interconnected bundles and nanoscale gaps between adjacent fibrils.

[0165] In some embodiments, cellulose nanofibrils include a mixture of elementary fibrils (e.g., about 2-5 nm in apparent diameter) and small bundles (e.g., about 10-40 nm in apparent diameter) whose arrangement and entanglement contribute to gel and sheet behavior. In some embodiments, the amount of non-cellulosic residuals surrounding the fibrils is relatively low compared to wood-derived nanocellulose, with residuals on the order of or less than about 20% by mass.

[0166] In some embodiments, individual cellulose fibrils in the nanocellulose network have nanoscale diameters. In some embodiments, average apparent fibril diameter is at least, equal to, or between any two of 2, 5, 10, 15, 20, 30, 40, 60, 80, 100, 150, and 200 nm, as determined from statistical analysis of microscopy images. In some embodiments, a majority of fibrils have apparent diameters less than about 40 nm, and in some embodiments at least, equal to, or between any two of 50, 60, 70, 80, and 90% of the fibrils in the network have apparent diameters in a range of 10-40 nm. These small fibril diameters can contribute to high specific surface area, efficient formation of percolated networks at low solids contents, and strong inter-fibrillar bonding in densified nanocellulose sheets. In some embodiments, the nanocellulose network is provided in the form of an aqueous gel. Nanocellulose gels are formed when the fibrillar network extends throughout the aqueous phase, producing a self-supporting material that does not flow under gravity at or above a certain solids concentration (the gel point). Gels derived from different biomass sources can exhibit different gel points, reflecting differences in fibrillation level, fiber aspect ratio, and residual components. In some embodiments, highly fibrillated, high-aspect-ratio cellulose nanofibrils can percolate at low solids content. Gels derived from date-derived nanocellulose fibrils may exhibit a wide range of gel points. In some embodiments, gel points for gels derived from non-wood biomass are at least, equal to, or between any two of 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, and 2.5 wt%.

[0167] Nanocellulose gels may exhibit shear-thinning behavior, wherein viscosity decreases with increasing shear rate. In some embodiments, nanocellulose gels exhibit high low-shear viscosity, suggesting a more strongly entangled network. In some embodiments, the gels display substantially frequency-independent G', indicative of a stable, elastic-dominant, true gel-like material. Thus, in some embodiments, the nanocellulose gel is configured to exhibit shear-thinning behavior and a storage modulus greater than the loss modulus over one or more frequency rangesClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1at small strain. In some embodiments, nanocellulose gels exhibit high dispersion stability. In some embodiments, nanocellulose gels do not appreciably sediment for at least, equal to, or between any two of 1, 2, 4, 8, 12, and 24 hours under quiescent conditions at room temperature.

[0168] In some embodiments, the nanocellulose network is provided in the form of a nanocellulose sheet. In some embodiments, nanocellulose sheets are substantially dehydrated. In some embodiments, nanocellulose sheets are densely packed, layered nanocellulose domains. Sheets can be formed by depositing a nanocellulose gel onto a substrate, draining or filtering off water, and drying to obtain a continuous network of nanofibrils. The resulting structures resemble nanopaper, with overlapping fibrils forming layered stacks and strong inter-fibrillar bonding via hydrogen bonding and mechanical entanglement. In some embodiments, sheet thickness is at least, equal to, or between any two of about 10, 20, 50, 80, 100, and 200 pm, depending on solids content, deposition volume, and drying / pressing conditions.

[0169] In some embodiments, nanocellulose sheets exhibit enhanced tensile strengths. In some embodiments, nanocellulose sheets exhibit ultimate tensile strengths that are at least, equal to, or between any two of 5, 10, 20, 30, 40, 50, 60, and 70 MPa, with strains at break that are at least, equal to, or between any two of 1, 2, 5, 10, and 16%, and elastic moduli that are at least, equal to, or between any two of 1000, 2000, 3000, 4000, 5000, and 6000 MPa. In some embodiments, nanocellulose sheets exhibit relatively lower ultimate tensile strengths and lower strains at break, for example due to residual macro-scale wrinkles or less complete fibrillation, while in other embodiments nanocellulose sheets exhibit tensile strengths and moduli comparable to reference nanocellulose sheets produced from other cellulosic sources. In some embodiments, nanocellulose sheets exhibit primarily elastic deformation up to failure at strains that are at least, equal to, or between any two of 0.5, 1.0, and 1.5%, whereas in other embodiments significant plastic deformation is observed prior to failure.

[0170] In some embodiments, nanocellulose sheets may exhibit various optical properties. In some embodiments, nanocellulose sheets exhibit relatively high transmittance in the visible region, indicating relatively high optical clarity. For the clearest sheets, transmittance can increase from around 1% in the UV region (e.g., at wavelengths below about 380 nm) to about 10% near the UV-visible boundary (e.g., around 400 nm), and can continue rising across the visible region to reach on the order of about 16% at wavelengths of approximately 800 nm. In other embodiments, nanocellulose sheets are largely opaque in the visible range, with transmittance remaining belowClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT11-2% across both UV and visible regions. Such opacity may be attributed to residual impurities, surface roughness, or both. In some embodiments, nanocellulose sheets exhibit less than 1% transmittance in the UV spectrum, indicating effective UV-blocking capability.

[0171] In some embodiments, cellulose nanofibrils comprise cellulose primarily in the cellulose I allomorph, with little or no conversion to cellulose II. X-ray diffraction (XRD) spectra of nanocellulose sheets may exhibit three main peaks at about 20 ~ 16.3°, 22.3°, and 34.8°, corresponding to the (110), (200), and (004) crystalline planes typical of cellulose I. According to some embodiments, the crystallinity indices (CrI) of cellulose nanofibrils according to this embodiment range from about 36.1% to about 62.8%, indicating that amorphous constituents are substantially removed while crystalline cellulose domains are preserved. In some embodiments, cellulose nanofibrils exhibit crystallinity indices of at least, equal to, or between any two of 36, 40, 45, 50, 55, 60, and 63%.

[0172] FTIR spectra of cellulose nanofibrils may show characteristic cellulose bands, including O-H stretching near 3362 cm C-H stretching near 2922 cm ', and C-O-C / C-O vibrations in the 1000-1200 cm1region. After processing, FTIR spectra show substantial reduction or disappearance of peaks associated with lignin and hemicellulose (e.g., at 1580, 1490, 1450, and 1730-1740 confirming effective removal of these non-cellulosic components while preserving cellulose structure.

[0173] In some embodiments, a plant growth substrate comprises an aqueous nanocellulose gel that includes water and cellulose nanofibrils having an average diameter in a range of 2-200 nm dispersed therein, the cellulose nanofibrils being obtainable by any of the methods described herein for producing cellulose nanofibrils from plant biomass having less than 15 wt% lignin (for example, method 100, including any of the optional embodiments thereof). In some embodiments, the cellulose nanofibrils of the plant growth substrate are obtainable by a method comprising providing a plant biomass having less than 15 wt% lignin, contacting the plant biomass with an aqueous medium at 20-100 °C to deconstruct the biomass and form a cellulose-rich fraction, separating the cellulose-rich fraction from the deconstructed biomass, and mechanically processing the cellulose-rich fraction in water to produce the cellulose nanofibrils, optionally with one or more repeated contacting and separating cycles as described herein.

[0174] In some embodiments, the plant biomass used to produce the cellulose nanofibrils has less than 15 wt% lignin and comprises tissue of one or more fruits or vegetables, for example fruit-Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1or vegetable-derived tissues as described herein. In some embodiments, the plant growth substrate is configured for use in an indoor farming system selected from hydroponic and aeroponic cultivation systems, for example as a mat, plug, or bed of aqueous nanocellulose gel. In some embodiments, the indoor farming system is an aeroponic system in which the aqueous nanocellulose gel supports plant roots while nutrient solution is intermittently sprayed or misted. In some embodiments, the plant growth substrate is formulated for growing microgreens. In some embodiments, the nanocellulose gel further comprises a microbial inoculant comprising Trichoderma dispersed within the gel to promote plant health and root development.

[0175] In some embodiments, nanocellulose gels or sheets produced according to method 100 are configured to act as substrates for hydroponic or aeroponic plant cultivation. Conventional hydroponic and aeroponic systems often use aqueous nutrient solutions together with synthetic or mineral substrates. In some embodiments, the plant growth substrate comprises an aqueous nanocellulose gel that is self-supporting at a cellulose nanofibril solids content of less than, equal to, or between any two of 2.5, 2.0, 1.5, or 1.0 wt%. In some embodiments, plants are cultivated directly on the aqueous nanocellulose gel substrates, with the gel acting both as a water-retentive support and as a structural medium compatible with standard indoor farming hardware. In some embodiments, yields of plants grown on substrates made from cellulose nanofibrils according to these methods are comparable to yields on conventional cellulose pulp-based or nanocellulose substrates, while using approximately 50% less fiber mass, indicative of efficient water and nutrient management and the high specific surface area of the nanocellulose network.

[0176] In some embodiments, plants such as microgreens grown on plant growth substrates comprising aqueous nanocellulose gels produced according to method 100 wilt more slowly than plants grown on conventional cellulose pulp-based substrates when subsequently stored under controlled temperature and humidity conditions. In some embodiments, plants cultivated on a plant growth substrate subsequently stored under controlled temperature and humidity may exhibit delayed wilting relative to the same plants cultivated on a cellulose pulp-based substrate under comparable conditions. In some embodiments, microgreens cultivated on such nanocellulose gel substrates and then stored at about 4 °C and about 90% relative humidity can remain visibly fresh for up to about 30 days, whereas comparable microgreens grown on cellulose pulp-based substrates wilt fully over similar time frames; in other embodiments, when stored at about 21 °C and about 62% relative humidity, microgreens grown on nanocellulose gel substrates can remain visibly freshClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1for up to about 20 days while microgreens grown on cellulose pulp-based substrates wilt completely over that period. In some embodiments, this delayed wilting behavior is attributed to the high surface area and water retention capacity of the nanocellulose network, which reduces dehydration stress and maintains moisture around roots and stems during storage. In some embodiments, nanocellulose substrates produced from food waste via the mild, low-energy processing routes described herein have substantially lower estimated production costs than conventional cellulose pulp-based or wood-derived nanocellulose substrates, particularly when bleaching is omitted and low-energy blending is used instead of ball milling or high-pressure homogenization, making these plant growth substrates attractive for indoor farming and other high-volume applications. In some embodiments, the process is further configured to be circular, such that harvested plant material from plants cultivated on nanocellulose gel substrates is reused as plant biomass feedstock for subsequent implementation of method 100 to produce additional cellulose nanofibrils, nanocellulose gel substrates, or both. In some embodiments, circularized plant biomass can include the cultivated plant’s roots, hypocotyls, stems, cotyledonary tissues, or other tissues that are rich in parenchymatous, low-lignin cells. In some embodiments using microgreens as the cultivated plants, circularized plant biomass can include the microgreen’s roots, hypocotyls, stems, cotyledonary tissues, or other tissues that are rich in parenchymatous, low-lignin cells.EXAMPLES

[0177] Example 1: Materials. Several sources of plant biomass were analyzed according to the procedures described herein. These include pineapple mesocarp, carrot periderms, watermelon, date fruit, date pomace. Pineapple mesocarp and carrot periderm were collected from kitchens at Khalifa University. Carrots (Australian imported), Khalas dates, and watermelons were purchased from supermarkets in Abu Dhabi, United Arab Emirates. Date pomace was obtained from a dateprocessing facility in the United Arab Emirates. All experiments using deionized (DI) water were conducted using DI water having a resistivity of about 15.0 MQ cm at 25 °C, produced using a water purification system (Elix®; Merck Millipore). tert-Butyl alcohol (TBA; ACS reagent, >99.0%) was purchased from Sigma Aldrich. Sodium hydroxide pellets (CAS No. 1310-73-2), hydrogen peroxide (30%), and anhydrous acetic acid (analysis grade, CAS No. 64-19-7) were obtained from Merck. Polyvinylidene fluoride (PVDF) membrane filters having a nominal pore size of 0.2 pm and a diameter of 90 mm were purchased from Sterlitech.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0178] Example 2: Cellulose nanofibril gel preparation. Tissues from several plant biomass sources were examined for this study: carrot xylem (CX), carrot periderm (CP), watermelon pericarp (WP) watermelon mesocarp (WM), date fruit (DF), and date pomace (DP). Each of these tissues may be characterized by low lignin content, high water content, and relatively soft mechanics before and after food-based processing.

[0179] The following procedure was used to process tissues to make cellulose nanofibrils (CNFs) and gels made thereof. An excess amount of DI water at room temperature was added to tissue samples and heated to bring the mixture to boil. Since then, it was allowed to continue boiling for 30 min. The washing water was discarded. This step comprised one washing cycle. For each tissue sample, multiple cycles of washing were done, but the number of cycles and water temperature varied. For CP samples, 4 washing cycles were done using a higher water temperature exhibiting high bubbling intensity For delicate samples such as WM, 3 washing cycles were done at boiling temperature (about 98-100 °C) under relatively gentle boiling, as indicated by lower bubbling intensity corresponding to lower heat input. For DF samples, 3 washing cycles were also done at boiling temperature under gentle boiling conditions, and during the third cycle the dates were immersed in freshly boiled water and then left to soak overnight at room temperature without continuous heating. In these procedures, bubbling intensity reflects the applied heat input (e.g., heating power and vessel configuration) rather than a change in bulk liquid temperature. For DP, CX, and WP samples, boiled DI water at a ratio of 1:10 (DP:DI water, w / v) was mixed with the pomace, covered with aluminum foil, and placed on a hot plate to maintain a temperature of about 80 °C with continuous slow stirring for 1 hour. While still hot, the pomace was subsequently filtered with a piece of cloth supported by a mesh sieve and was gently pressed to remove excess water. This procedure was then repeated for an additional 1 hour at about 80 °C with continuous slow stirring, followed by hot filtration and gentle pressing, so that the DP samples underwent two washing cycles to ensure thorough washing. Following washing cycles, the tissue samples were strained from the water and cooled to room temperature.

[0180] Washed tissue samples were then added to DI water at a ratio of 2:1 (DI watertissue sample). Samples were then blended using 500W Kenwood blender (BLP16.150WH) at lowest power setting for 5 minutes. Samples were then centrifuged at 5000 rpm for 15 min to separate cellulose nanofibrils from water. The separated CNFs exhibited gel-like properties in water, and such CNFs are hereafter described as CNF gels. For DF and DP samples, multiple centrifugationClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1cycles were performed, with the resulting product being separated from black tannins residues until maximum possible separation was achieved while ensuring optimum gel recovery.

[0181] FIG. 2A illustrates images of date (left), carrot (middle), and watermelon (right) tissues before contacting with an aqueous medium, according to some embodiments. FIG. 2B illustrates images of date (left), carrot (middle), and watermelon (right) tissues after contacting with an aqueous medium, according to some embodiments. FIG. 3A illustrates images of a watermelon tissue before (left) and after (right) contacting with an aqueous medium, according to some embodiments. FIG.3B illustrates images of a carrot tissue before (left) and after (right) contacting with an aqueous medium, according to some embodiments.

[0182] FIG. 4 illustrates images of networks of cellulose nanofibrils in the form of an aqueous gel made from the tissue of DF, CX, CP, WM, WP, and DP, according to some embodiments. The colors of several sample-derived cellulose nanofibril networks resulted from residual components retained from the original samples.

[0183] Example 3: Solid content and Yield analysis. The solid content (%) of cellulose nanofibril gels was determined by measuring their mass before (mw) and after (md) drying in the oven at 50°C and overnight to evaporate all the moisture presents in the samples:z Amdsolid content (%) = - X 100%mw

[0184] Two solid content values were obtained for each sample: (i) the total mass of solids before processing and (ii) the total mass of solids after processing. The overall yield of cellulose nanofibril extraction process was then calculated as the product the two solid content values using the following equation:total mass of solids after processingYield= T toTtali - mass o rf so rliads n be rfore p -rocessi -ngX 100%

[0185] FIG. 5 illustrates a chart showing comparative % yields post-hydrothermal treatment, post-processing, and total, where the total yield refers to the overall fraction of solids retained after the entire extraction process, according to some embodiments. The highest yields after hydrothermal treatment were observed for DP (51%) and CP (36%), whereas the lowest yields were WM and DF at 5.5% and 7.9%, respectively. All samples showed relatively high yields following the subsequent processing step. The highest total yield was measured for CP at around 32%, followed by DP at 23%.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0186] Example 4: Alkali and bleach treatments. Some preparation processes of cellulose nanofibril gels also included alkali and bleach treatments according to the following procedures. Pineapple mesocarp (PM) samples were alkali treated by thoroughly washing samples with water, blending, and soaking in a 4 wt.% NaOH solution for 48 hours at room temperature. The soaking step did not use additional heat or mechanical stirring processes. After soaking, the fibers were rinsed with water repeatedly until a neutral pH was achieved. The treated fibers were then stored in a refrigerator at 4°C for use in subsequent experiments.

[0187] Alkali-treated PM samples were then subjected to a combined boiling and bleaching treatment by being processed in a 5 wt% hydrogen peroxide (H2O2) solution at about 80 °C for 2 hours, for example after blending, soaking in NaOH, and rinsing to neutral pH. During this step, the fibers were maintained at the target temperature (e.g., on a hot plate) so that boiling in the H2O2 solution and bleaching occurred simultaneously. After bleaching, the fibers were thoroughly washed with deionized water until a neutral pH was achieved, and the washed fibers were then stored in a refrigerator at about 4 °C for use in subsequent experiments. Raw pineapple mesocarp fibers exhibit resistance to processing when processed using a blender which results in most of the fibers remaining at the microscale or larger. Such resistance is effectively reduced by adding an alkali treatment step, after which, the fibers become highly susceptible to mechanical processing. Introducing a secondary blending step after alkali treatment alone, or alkali treatment and bleaching, enables the obtaining of nano-scale fiber gels. FIGS. 6A-D illustrate images of nanocellulose gels derived from PM used as substrates for growing mustard microgreens, according to some embodiments.

[0188] Example 5: SEM analysis. The structure and size of cellulose nanofibril gels and cellulose nanofibril sheets were analyzed using a Quanta™ 450 FEG scanning electron microscope (SEM). For cellulose nanofibril gels, a droplet of a diluted nanofibril suspension (0.005%) was placed onto a gold-coated silicon wafer and left to dry at room temperature overnight. SEM images were then captured at an accelerating voltage of 3 kV.

[0189] For morphological analysis of unprocessed biomass, samples were freeze-dried, immersed in TBAfor 10 minutes, and analyzed using a scanning electron microscope (JEOL JSM-7610F FEG-SEM). For morphological analysis of processed cellulose nanofibrils, a 0.001-0.005 wt% droplet of nanofibril suspension was placed onto a gold-coated silicon wafer and left to dry at room temperature overnight.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0190] SEM images were then captured at an accelerating voltage of 5 kV and emission current of around 60 pA. At similar conditions, surface and cross-sectional morphology of the thin sheets were also analyzed using SEM before and after mechanical testing. The diameter of cellulose nanofibrils was then measured from SEM images using ImageJ software (NIH, USA). Diameter values from +100 individual fibrils were collected across several micrographs to establish a size distribution histogram. Surface topography of the fibers was also analyzed using atomic force microscopy (CSI NanoObserver 2 AFM). 0.001 wt% droplets of CNWP and CNDF were placed on silicon wafers. Cantilever with a nominal resonance frequency of -300 kHz was employed. The images were further analyzed using Gwyddion 2.69 software (Czech Metrology Institute, Czech Republic).

[0191] FIGS.7A-B illustrate SEM images of carrot periderm following hydrothermal treatment, according to some embodiments. FIGS. 8A-B illustrate SEM images of watermelon mesocarp following hydrothermal treatment, according to some embodiments. FIGS. 9A-C illustrate SEM images of date fruit following hydrothermal treatment, according to some embodiments. These results indicate that the treated biomass highlighted thin cell walls and loose nanofibrils present in the resulting nanonetworks. Across the different plant biomass types, the lumen cross-sectional size ranged from approximately 16.7 pm in CP up to approximately 318 pm in WM, with the largest cells observed in WM. Such large, thin-walled parenchyma cells are characteristic of tissues with high water content, where the primary function is storage of water, soluble sugars, nutrients, and metabolites rather than mechanical support. In these tissues, pectin, cellulose, and hemicellulose typically predominate, and lignin is nearly absent, in contrast to structural or vascular regions (for example, xylem) where lignification contributes to rigidity. Distinct nanofibril networks with nanoscale gaps between adjacent nanofibrils were evident in all samples, consistent with removal of non-cellulosic components by hydrothermal pre-treatment and exposure of underlying nanocellulose structures.

[0192] FIGS. 10A-D illustrate SEM images of cellulose nanofibrils derived from CP, according to some embodiments. FIGS. 11A-C illustrate SEM images of networks of cellulose nanofibrils derived from CX, according to some embodiments. FIGS. 12A-C illustrate SEM images of networks of cellulose nanofibrils derived from WM, according to some embodiments. FIG. 13 illustrates an image of cellulose nanofibrils derived from PM tissue, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0193] The results of at least the CX SEM analysis demonstrate that minimal processing of only 5 minutes of low power blending was sufficient to obtain cellulose nanofibril gels from such samples. Such findings suggest that non-wood biomass, such as fruits and vegetables, naturally contain cellulose fibers at the nanoscale and does not require extensive processing to fibrillate or isolate them. The same was tested on WM samples and similar results were obtained, wherein a generalized approach can be extrapolated for low lignin-containing plants. Size distribution analyses of the extracted cellulose nanofibrils was conducted based on the obtained SEM images. The resulting cellulose nanofibrils are referred to herein as follows: carrot xylem derived (CNCX), carrot periderm derived (CNCP), watermelon pericarp (CNWP), watermelon mesocarp derived (CNWM), date fruit derived (CNDF), and date pomace derived (CNDP).

[0194] FIGS. 14A-F illustrate SEM images of CNDF, CNCX, CNCP, CNWM, CNWP, and CNDP networks of cellulose nanofibrils, respectively. These results indicate that samples were nanofibrillated, without evident fractions that did not undergo sub-cellular sizes fractionation. Further, these results show a high degree of fibrillation reaching an average diameter of 80.4 nm.FIG. 15 illustrates a chart showing average diameters of CNDF, CNCX, CNCM, CNWM, CNWP, and CNDP, according to some embodiments. FIGS. 16A-F illustrate charts showing average diameters of CNDF, CNCX, CNCP, CNWE, CNWP, and CNDP cellulose nanofibrils, according to some embodiments.

[0195] All cellulose nanofibrils consisting of either elementary fibrils or bundles, exhibited average apparent diameter lower than 40 nm. CNWP yielded the finest fibers, with the lowest average diameter of 16.6 ±6 nm being observed, as further displayed in its significantly narrower distribution curve compared to other samples. CN date pomace had an average diameter of 31.6 ±11.5 nm comparableto that of CNCP (30.6± 10.2 nm). These results also indicate CN date pomace has greater variability, evidenced by residual particles being still present and not fully removed. CNDF and CNWM nanofibrils were larger, with average diameters of 36± 14.4 nm and 36.7± 12.1 nm, respectively.

[0196] Example 6: Atomic force microscopy (AFM) analysis. The nanoscale morphologies of cellulose nanofibril isolated from watermelon pericarp was further characterized using AFM. FIG.17 illustrates an AFM image of cellulose nanofibrils derived from watermelon mesocarp (samples WM1-4), according to some embodiments. FIG. 18A illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp (sample WM1), according to someClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1embodiments. FIG.18B illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp (sample WM2), according to some embodiments. FIG. 18C illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp (sample WM3), according to some embodiments. FIG. 18D illustrates a chart showing a height profile of a cellulose nanofibril derived from watermelon mesocarp (sample WM4), according to some embodiments.

[0197] As seen in these results, cellulose nanofibrils derived from watermelon mesocarps exhibited a high degree of fibrillation, where the height profiles showed diameters between 2.1 and 5.4 nm, clearly showcasing elementary sized nanofibrils. The presence of smaller fibers than those previously reported in wood could be associated with the fact that the cellulose may aggregate in an uncontrolled manner as a result of a high pectin content in the extracellular matrix. Though some reports suggested that such sizes could also be observed from wood cellulose nanofibrils. The succession of amorphous and crystalline domains was also evidenced by the presence of kinked regions for the smaller fibers. Previous studies proposed that kinks occur at the amorphous domains of cellulose, where the fibrils chains are less ordered and thus more susceptible to local bending or slippage under stress. The results of this example demonstrate that the highest grade of nanocellulose can be extracted in its pristine state due to the lack of treatments affecting paracrystallinity of cellulose and its surface functional groups. Of note, the amount of residuals apparent around the fibers was surprisingly small compared to wood, where up to 20% residuals are associated with hemicelluloses, which typically form nanoparticles within the wood-cellulose nanofibril gels.

[0198] Example 7: X-ray diffraction (XRD) analysis. X-ray diffractometer (XRD PANalytical Empyrean) was used to evaluate the crystallinity of the samples. Cu-Ka radiation was used to obtain diffraction data over a 20 range of 5° to 80° at 45 kV and 40 mA. FIG. 19 illustrates six x-ray diffraction (XRD) spectra of CNDP, CNWP, CNWM, CNCP, CNCX, and CNDF networks of cellulose nanofibrils, according to some embodiments. FIGS.20A-F illustrate XRD spectra of DF, CX, CM, WM, WP, and DP plant biomasses before and after processing, according to some embodiments. In these figures, post-processing samples have the prefix “CN” and pre-processing samples have no prefix.

[0199] XRD analysis of the obtained cellulose nanofibril from 6 different non-wood sources revealed three distinct peaks at 20 ~ 16.3°, 22.3°, and 34.8°, corresponding to the (110), (200) andClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1(004) crystalline planes, typical of plant’s cellulose I allomorph. The crystallinity index (CrI (%)) was calculated using Segal’s equation:

[0200] The apparent CrI of the cellulose nanofibrils showed that CNWP exhibited the highest crystallinity of around 62.8%, followed by CNCX(52.6%), CNDF (46.7%), CNWM (44.0%), CNCP (38.7%), and CN date pomace (36.1%). Removal of crystal forming non-cellulosics is apparent in all samples, where comparing to raw samples - particularly considering the reduction of the broad amorphous hump between 20 ~ 15° and 22.5°.

[0201] Example 8: Gelling point analysis. A known mass and solid (%) of wet fibers gel was placed in a container (glass jar). Water was gradually added drop by drop to the sample, to dilute the mixture, and mixed using vortex mixer to ensure uniform distribution. The jar was then inverted for 1 min to observe the behavior under the effect of gravity. This procedure was repeated until the wet fibers lost their integrity and began to flow or fall. The concentration, solid (%), of the gel at this stage is called the gel point or gelling point.

[0202] FIG. 21A illustrates a graph showing gelling point concentrations of gels made from CNDF, CNCX, CNCP, CNWP, CNWM, and CNDP, according to some embodiments. FIG. 21B illustrates a chart showing gelling point % values of nanocellulose gels made from carrot xylem and carrot periderms, according to some embodiments. CNWP exhibited the lowest gelling point concentrations obtained by tube inversion assays of 0.68%, which could be attributed to a highly fibrillated cellulose nanofibril structure, characterized by a small fiber diameter as also suggested by SEM and AFM micrographs analysis. An increasing interaction with water is unlocked with the higher surface area of the watermelon pericarp nanofibrils and their high aspect ratio leads to gelation at low concentration, below what is typically observed for wood nanocelluloses.

[0203] CNDP showed the highest gel concentration at ca. 2.0% followed by CNDF at ca. 1.48%. This trend was also observed in the gelation behavior of CNWM, which exhibited a gelling point close to that of CNDF, at 1.39%. Difference in gelation concentrations, which cannot be directly associated with diameters measured, are likely to be associated with floc size and individualization of nanofibrils. Residuals, such as phenolic compounds, may also play a role as they can alter fiberfiber interactions.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0204] For gels made from CNCP, CNWM, CNDF, and CNDP this processing route provided a near-complete transformation of the biomass into cellulose nanofibrils, with gelation concentrations typically in the range of about 0.68-2.0 wt% and apparent fiber diameters comparable to those observed for elementary cellulose fibrils. Generally, all gels showed ability to retain their fibers network integrity at low concentrations. However, CNCX has a lower gelling point than CNCP; this indicates a higher degree of fibrillation of the cellulose nanofibrils in the xylem. In particular, the gel point of carrot xylem reached about 1.08 wt%, whereas the gel point of carrot periderm was about 1.39 wt%.

[0205] Following gel point was also conducted on alkali-treated and bleached pineapple mesocarp nanofibrils. FIG. 22 illustrates an image showing results of gelling point analysis of a nanocellulose gel derived from pineapple tissue, according to some embodiments. These results indicate that the gel point is approximately 1.27 wt%, indicating that these fibers also form stable gels at relatively low solid contents.

[0206] Example 9: UV-Vis Spectroscopy Analysis. UV-vis absorbance spectra of both the supernatants and gels collected after centrifugation were measured using LAMBDA 1050 UV / Vis / NIR spectrometer at a wavelength range of 200-900 nm, with 1 nm interval. Prior testing, the gels and their corresponding supernatants were diluted to 0.01 wt%. UV-vis transmission spectra of the sheets were acquired at the same conditions. Freestanding sheets were mounted directly in the beam path, with air as the reference. All measurements were performed at room temperature.

[0207] FIG.23A illustrates a UV-vis spectrum of CNDF, according to some embodiments. FIG.23B illustrates a UV-vis spectrum of CNCX, according to some embodiments. FIG.23C illustrates a UV-vis spectrum of CNCP, according to some embodiments. FIG. 23D illustrates a UV-vis spectrum of CNWM, according to some embodiments. FIG. 23E illustrates a UV-vis spectrum of CNWP, according to some embodiments. FIG. 23F illustrates a UV-vis spectrum of CNDP, according to some embodiments. UV-Vis spectroscopic analysis indicated that CNCP and CNWP did not have specific adsorption peak between 200 and 900 nm, wherein only a slight shoulder could be observed at 280 nm. A clearer adsorption band was more clearly observed for CNDP, CNDF, and CNWM, which is more likely to be associated with phenolic residues rather than protein given the original nature of the tissues Absorbance at 900 nm is dominated by light scattering rather than molecular absorption and therefore reflects the relative opacity or turbidityClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1of each dispersion. At this wavelength, the CNWP sample exhibited the lowest absorbance, indicating the least scattering (i.e., the highest clarity) among the tested networks of cellulose nanofibrils. For all samples, it is likely that a set of residuals are convoluted, leading to the absence of clear adsorption bands. This suggests the presence of aromatic or phenolic compounds, reflecting their higher gelling thresholds (2.0% and 1.48%, respectively).

[0208] UV spectra of the supernatant were also analyzed. FIG.24A illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNDF, according to some embodiments. FIG. 24B illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNCX, according to some embodiments. FIG. 24C illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNCP, according to some embodiments. FIG. 24D illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNWM, according to some embodiments. FIG.24E illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNWP, according to some embodiments.FIG. 24F illustrates a UV-vis spectrum of supernatant taken after centrifugation of CNDP, according to some embodiments. At around 200-220 nm, all samples showed a dominant peak, with the highest intensity observed for the CNDF and CNDP supernatants. Another pronounced peak at around 280 nm was also evident in these same samples (CNDF and CNDP). These peaks are attributed totransition in aromatic compounds such as residual phenols, tannins or small lignin-derived fragments, that contain chromophoric groups capable of absorbing in this range. At around 460 nm, a distinct peak observed mainly on the UV spectra of CNCX and CNCP supernatants, but not on those of the other samples. This peak corresponds most likely to carotenoids (P-carotene), a characteristic pigment in carrots. These results confirm that non-cellulosic compounds and other water-soluble extractives, commonly present in fruit wastes, were further removed during centrifugation step, as shown in the SEM image of CNWM supernatant with fine fibers also observed.

[0209] Example 10: FTIR analysis. Fourier-transform infrared (Bruker Vertex 80v FT-IR) was used to evaluate the chemical composition and functional groups of the cellulose nanofibril before and after treatment. The samples were crushed after oven drying using piston and mortar, then they were pressed using hand operated pellet press.

[0210] FIGS. 25A-F illustrate superimposed FTIR spectra of CNDF, CNCX, CNCP, CNWP, CNWM, and CNDP before and after processing, according to some embodiments. FIG. 26 illustrates six FTIR spectra of nanocellulose networks derived from CNDF, CNCX, CNCP, CNWP,Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1CNWM, and CNDP, according to some embodiments. Distinct FT-IR peaks corresponding to O-H stretching (3362 cm-1), C-H stretching (2922 cm-1), and C-O-C / C-O vibrations (1000-1200 cm-1) are observed in the processed materials. These features are characteristic of cellulose FT-IR spectra. The FTIR spectrum of the processed samples also shows the disappearance of lignin-associated peaks at 1580, 1490, and 1450 cm ', as well as the aromatic C-H out-of-plane bending at 830-870 cm along with the loss of the hemicellulose-related C=O stretching at 1730-1740 while retaining the cellulose bands, confirming the effective removal of lignin and hemicellulose and the preservation of the cellulose structure.

[0211] Example 11: Rheological analysis. Rheological measurements of the extracted cellulose nanofibrils were performed using rotational rheometer (Anton Paar H-PTD 220 FOR MCR) at a concentration of 2 wt%. Measurements were conducted at 20°C using a parallel plate geometry of 25 mm diameter and fixed 1 mm gap. To determine the viscous behavior of the samples, shear flow tests were conducted over a shear rate range of 0.1 to 1000 s-1. Viscosity as a function of shear rate were recorded at 16 logarithmically spaced points. Amplitude sweep tests were performed to determine the linear viscoelastic region (LVR) in the strain range of 0.01-100% at a constant angular frequency of 1 rad / s. The LVR limit was identified, and a conservative strain amplitude of 0.01% was selected. Subsequently, frequency sweep tests were carried out in the range of 0.1-100 rad / s, within the LVR (strain of 0.01%), using 16 logarithmically spaced points, to determine the storage modulus (G') and loss modulus (G"). To assess thermal stability and structural changes of the cellulose nanofibril suspensions, temperature ramp tests were also conducted from 20 to 80°C, under fixed strain of 0.01% and oscillation frequency of 1 Hz.

[0212] FIG. 27A illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from DF samples, according to some embodiments. FIG. 27B illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from CX samples, according to some embodiments. FIG.27C illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from CP samples, according to some embodiments. FIG. 27D illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from WM samples, according to some embodiments. FIG. 27E illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrils derived from WP samples, according to some embodiments. FIG. 27F illustrates a graph showing results of shear rate analysis of a network of cellulose nanofibrilsClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1derived from DP samples, according to some embodiments. To study the flow behavior of the gels, shear stress was measured as a function of shear rate, and the viscosity vs. shear rate curves were subsequently constructed. All samples exhibited shear-thinning behavior, as expected for cellulose nanofibril suspensions. At low shear rate, CNWP showed the highest viscosity, while CNWM showed the lowest, suggesting that CNWP possesses a more strongly entangled cellulose nanofibril network compared to the others. Up to a shear rate of around 1 s-1, all samples showed comparable slopes, indicating similar initial flow behavior. However, at high shear rates, CNDP demonstrated a steeper profile, reflecting greater sensitivity to shear and ultimately reaching a lower final viscosity than CNWM and the other samples.

[0213] The microstructure of viscoelastic materials determines the form of the frequency sweep curves, which were herein studied at a strain of 0.01% as it was determined from amplitude sweep test. Over the entire stain range, both CNWP, and CNCX showed storage modulus (G') higher than loss modulus (G") representing an elastic dominant gel with a stable structure. Moreover, the G' curve of both samples is nearly flat, frequency independent, suggesting stable and a true gel-like materials with strong fiber-fiber interactions occurring. The highest stability was observed for CNWP with the values of dynamic moduli reaching up to around 3700 Pa, and 950 Pa for G' and G", respectively. An important factor influencing the storage modulus of cellulose nanofibril gels is the aspect ratio of the fibers. Materials with a high aspect ratio tend to form extensive entanglements, which restricts fiber mobility under flow and leads to the formation of a stable, interconnected network, resulting in a higher storage modulus. This further infers that watermelon pericarp and carrot xylem based gels have higher aspect ratio fibers. The remaining samples, CNDF, CNWM, CNCP, and CNDP, showed a higher G' than G"; however, at higher frequency, a crossover is observed reflecting disruption of the gel network under faster oscillations and points to the presence of a sol-gel transition or a weak gel structure that breaks down at higher frequencies. Across the entire temperature range (20-80°C), all gels exhibited storage moduli significantly higher than their corresponding loss moduli, confirming that the systems maintain a predominantly elastic, gel-like character. Fluctuations mainly in G" were observed mostly in CNDF- and CNDP-based suspensions. Such instability may arise from residual components or impurities that interfere fibril-fibril interactions, thereby destabilizing the network and leading to more sensitive viscous response to temperature variations.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0214] Example 12: TGA analysis. Thermogravimetric Analysis (TGA) was done using a high-temperature TGA system (STA 449 F3 Jupiter series, Netzsch, Germany). Measurements were conducted on ~5 mg specimens under an air purge flow of 30 mL / min and employing a heating program from 40°C to 1000°C at a constant rate of 5°C / min. Derivative thermogravimetric (DTG) curves were obtained for all fiber samples to assess decomposition stages.

[0215] To investigate the fibers’ thermal decomposition and mass loss profiles, TGA analysis was performed. FIG. 28A illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from DF samples, according to some embodiments. FIG.28B illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from CX samples, according to some embodiments. FIG. 28C illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from CP samples, according to some embodiments. FIG. 28D illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from WM samples, according to some embodiments. FIG. 28E illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from WP samples, according to some embodiments. FIG. 28F illustrates a graph showing results of thermogravimetric analysis of a network of cellulose nanofibrils derived from DP samples, according to some embodiments. The TGA curves of the obtained samples display the thermal degradation behavior of the cellulosic materials show typical three stage weight loss patterns. The initial minor loss below 110°C corresponds to moisture evaporation, the major degradation between around 250°C and 380°C corresponds to cellulose depolymerization and glycosidic bond cleavage, and the residual mass above 400°C represents char formation and degradation of the remaining inorganic residues.

[0216] Example 13: Sedimentation analysis. Fiber suspensions (0.25 wt% in 5 mL of DI water) were sonicated for 5 minutes to guarantee uniform dispersion in order to improve dispersion stability. The suspensions were then left to settle undisturbed in glass containers for a full day. In order to compare the sedimentation profiles of the various fiber suspensions, which were all created at similar beginning volumes, photographic images were recorded throughout the settling process.

[0217] To examine the dispersion stability of the 6 gels, stability assays were done by sedimentation over prolonged times. FIG. 29 illustrates a chart showing percentage drop of cellulose nanofibrils over time during sedimentation tests of CNDF, CNCX, CNCP, CNWM,Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1CNWP, and CNDP, according to some embodiments. FIG. 30 illustrates images of sedimentation analysis of cellulose nanofibrils made from DF, CX, CP, WP, WM, and DP samples, according to some embodiments. Within the first 7 minutes, a rapid 80% sedimentation was observed in CNDP forming a sedimented gel layer at the bottom and leaving an almost clear supernatant above. This was followed by an equilibrium phase with no further change in height for the remainder of the test. CNCP followed a similar pattern but with 70% of the sedimentation occurring in two stages: an initial rapid sedimentation of 60% within the first 15 minutes, followed by 10% that occurred at lower rate. Afterward, the sedimentation height stabilized, leaving a visibly turbid supernatant, indicating partial fiber suspension. CNWM demonstrated the highest dispersion stability, as they did not sediment throughout the 24-hour test. This was followed by CNCX, which exhibited gradual sedimentation over multiple stages. Less than 10% occurred within the first 5 minutes, and the test ended with less than 25% of partial sedimentation. Among the samples, CNDF showed a moderate stability, with the sedimentation front remaining at approximately 50% of the initial suspension height at the end of the test.

[0218] 0.2% fiber solutions in water were prepared for the different samples and kept in narrow glass jars. The solutions were then left to settle in the jars starting from full height and the final sedimentation heights were recorded after 24 hours.

[0219] Sedimentation assays were also done on pineapple tissue having been treated with various pretreatments. FIG. 31 illustrates suspension stability results of pineapple tissue having been treated with different combinations of alkali treatment (AT), bleaching (BL), and mechanical processing (ball milling, BM), including raw fiber, alkali-treated (AT), alkali-treated and bleached (AT+BL), alkali-treated, bleached, and ball-milled (AT+BL+BM), and alkali-treated, bleached, and blended for 30 minutes (AT+BL+B1), according to some embodiments. These results show the final sedimentation heights of 0.2% solutions observed after 24 hours for raw, alkali-treated, alkali-treated and bleached, and alkali-treated bleached and blended PM fibers. While alkali treatment increased sedimentation height, no significant change was observed after bleaching. However, secondary blending led to a substantial increase in sedimentation height with minimal visible separation from the bulk of the solution, indicating enhanced dispersibility.

[0220] Example 14: Planting trials, cellulose nanofibril gels made from samples were used as substrates for microgreen growing and compared with a commercially available (control) cellulose nanofibril gel according to the following procedure. A fixed amount of Trichoderma was mixedClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1with water to ensure proper dispersion, after which cellulose nanofibril gels were added. The control substrate used 5% cellulose nanofibril gel and the sample substrate used 2.5% sample cellulose nanofibril gel. The mixture was thoroughly blended and evenly distributed into the punnets. The plastic punnets were sanitized with 1% H2O2 before use. Then, a fixed quantity of mustard seeds was then spread uniformly across the prepared substrate. Six replicates were prepared for each treatment.

[0221] Plants were first germinated in a controlled germination chamber and then transferred to a planting chamber, where the substrates were periodically irrigated with a nutrient solution formulated specifically for microgreens over a nine-day period. After this period, the plants were harvested for analysis under wilting trials. Wilting trials consisted of placing plants under controlled conditions to evaluate their response to water stress after being harvested. The primary objective was to assess the water retention capabilities of the substrates, including conventional pulp-based substrates. Two storage conditions were tested: one in a refrigerator at 4°C with 90% relative humidity, and the other at room temperature (21 °C) with 62% relative humidity. Over a 10-day interval, photographs of the punnets were taken at regular intervals, and visual observations of wilting were monitored to assess substrate performance and plant response to water stress under these differing conditions.

[0222] FIG. 32 illustrates images showing results of comparative wilting analysis using conventional pulp substrates and nanocellulose gel derived from plant biomass, according to some embodiments. These results indicated the ability of different substrates to maintain the freshness of microgreens under two storage conditions: room temperature (21 °C with 62% relative humidity) and refrigeration (4°C with 90% relative humidity). At room temperature, microgreens grown on the commercial pulp substrate completely wilted after 20 days, while those on the nanofibril-based substrate remained visibly fresh. Similarly, under refrigerated conditions, microgreens on the commercial pulp substrate wilted completely after 30 days, while those on the nanofibril substrate still appeared fresh. These results highlight a clear difference in the substrates' ability to retain moisture and maintain plant freshness over extended periods. The performance of the nanofibril substrate is attributed to its high surface area and excellent water retention properties, which help sustain the moisture levels required by the plants. Unlike commercial pulp, which loses water more quickly and dries out the substrate, nanofibrils can hold onto water more effectively, reducing dehydration stress on the plants. This ability allows microgreens grown on nanofibril substrates toClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1maintain their freshness for longer, even under conditions that typically promote wilting. These findings suggest that cellulose nanofibril gel substrates made according to processes described herein are a promising, sustainable alternative to commercially available cellulose nanofibril gels for improving the post-harvest shelf life of microgreens.

[0223] FIGS. 6A-D illustrate results of nanocellulose gels made from PM treated with various combinations of alkali and bleach. These results highlight the promising performance of fibers treated with mild alkali processes from food waste as a sustainable alternative to conventional substrates. The alkali-treated fiber derived from food waste yielded 18.66 ± 1.29%, while the alkali-plus-bleached fiber produced a slightly higher yield of 18.85 ± 1.43%. These results indicate that the mild alkali treatment alone is sufficient to produce a substrate capable of supporting plant growth comparable to commercially available sources (19.76 ± 0.52%) without the need for more intensive processing, such as bleaching. In contrast, the alkali-autoclaved and alkali-blended fibers showed slightly lower yields of 17.40 ± 0.93% and 17.12 ± 0.26%, respectively, potentially due to differences in fiber structure or processing effects that could influence substrate uniformity or nutrient availability. Oven-dried fibers performed poorly, with a yield of just 5.63 ± 0.79%, likely because the drying process might have degraded the structural integrity and reduced the substrate's water-holding capacity.

[0224] It is significant to note that these high yields were achieved while using 50% less fiber compared to commercial products, highlighting the efficiency of the treated fibers. The ability of mild alkali treatment to produce high-performing substrates without the additional energy- and resource-intensive bleaching process makes this approach particularly attractive for sustainable and cost-effective hydroponic applications. This approach not only reduces fiber consumption but also minimizes environmental impact, aligning with the goals of resource efficiency and waste valorization.

[0225] Example 15: Cellulose nanofibril sheet preparation. Cellulose nanofibril sheets were prepared using cellulose nanofibril gels according to the following procedure. 40 mL of 0.4 wt% of cellulose nanofibril gels were filtered on PVDF membrane filters using vacuum filtration setup. The resulting cellulose nanofibril sheets were then left to dry overnight at room temperature and subsequently detached from the membrane. To ensure smooth surface and uniform thickness, the sheets were hot-pressed at 80°C for 2 min using heat pressing machine (IMPRESOMATIC 38x38cm).Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0226] To explore the potential of the extracted cellulose nanofibrils for material applications, the prepared gels were tested for their sheet-forming ability. FIG. 33 illustrates images of nanocellulose sheets derived from CNDF, CNCX, CNCP, CNWP, CNWM, and CNDP, according to some embodiments, with two additional images of CNWM zoomed in. FIG. 34 illustrates an SEM image of a cross section of a nanocellulose sheet derived from CNWM, according to some embodiments. FIG. 35 illustrates an XRD spectrum of a commercially available reference cellulose paper. This reference pattern is included to confirm the crystalline structure of the extracted cellulose by comparison, demonstrating that the isolated cellulose exhibits the characteristic diffraction peaks of cellulose I and thereby validating that non-cellulosic components have been successfully removed while preserving the structural integrity of the cellulose phase.

[0227] Sheet morphology enables relative performance in the dried state to be evaluated. The appearance of the sheets was smooth, and the colors reflected those of the gels. Macro-aggregates were visible on all sheets, suggesting that a fraction of large fibers remained. CNWP sheets and CNDP sheets were shown to form nanolayered stacks of nanocellulose, typical of so-called nanopaper but only WP presented a smooth surface, as associated with large unfragmented residuals.

[0228] A key performance property across various applications of nanocellulose-based sheets is their interaction with light, as quantified by UV-vis transmittance measurements. All samples showed a monotonic increasing trend of the T (%) with wavelength, with difference in magnitude and slope among each sheet. In the visible region (400-800 nm), both CNWP and CNCX sheets exhibited the highest T (%) reaching more than 14%. This indicates their high optical clarity with superior nanofibril dispersion. However, CNDP sheets remained nearly opaque with less than 2% T. This significant light absorption is likely associated with poor dispersion, high surface roughness or degree of wrinkles, and the presence of residual contents or other UV-absorbing impurities. In the UV region (200-400 nm), CNDP sheets and CNCP sheets showed relatively low transmittance, below 1%, indicating enhanced UV-blocking capability.

[0229] Example 16: Nanocellulose sheet analysis. Stress-strain behavior revealed significant variation in the mechanical properties depending on the feedstock. Tensile testing was performed on sheets cut into standardized dogbone-shaped specimens with a narrow section measuring 20 mm x 3 mm. The measurements were conducted in the dry state using a universal tensile testerClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1(Instron 5966, USA) equipped with a 10 kN load cell. Typically, three to five specimens per sample were tested Theologically.

[0230] FIG. 36A illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNDF, according to some embodiments. FIG. 36B illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNCX, according to some embodiments. FIG. 36C illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNCP, according to some embodiments. FIG. 36D illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNWM, according to some embodiments. FIG. 36E illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNWP, according to some embodiments. FIG. 36F illustrates a graph showing results of rheological analysis of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0231] FIG. 37A illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNDF, according to some embodiments. FIG. 37B illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNCX, according to some embodiments. FIG. 37C illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNCP, according to some embodiments. FIG. 37D illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNWM, according to some embodiments. FIG. 37E illustrates a graph showing representative tensile stress-strain response of a nanocellulose sheet derived from CNWP, according to some embodiments. FIG. 37F illustrates superimposed graphs showing representative tensile stress-strain response of a nanocellulose sheet derived from CNDP and a comparable wood sample, according to some embodiments.

[0232] FIG. 38A illustrates a graph showing ultimate tensile strength test results of nanocellulose sheets derived from CNDF, CNCX, CNCP, CNWP, CNWM, CNDP, and wood, according to some embodiments. FIG. 38B illustrates a graph showing strain at failure test results of nanocellulose sheets derived from CNDF, CNCX, CNCP, CNWP, CNWM, CNDP, and wood, according to some embodiments. FIG. 38C illustrates a graph showing elastic modulus test results of nanocellulose sheets derived from CNDF, CNCX, CNCP, CNWP, CNWM, CNDP, and wood, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0233] Nanocellulose sheets were also analyzed with UV-vis spectroscopy, TGA analysis, and SEM microscopy. FIG. 39A illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNDF, according to some embodiments. FIG. 39B illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNCX, according to some embodiments. FIG. 39C illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNCP, according to some embodiments. FIG. 39D illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNWM, according to some embodiments. FIG. 39E illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNWP, according to some embodiments. FIG. 39F illustrates a graph showing results of thermogravimetric analysis of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0234] FIG. 40A illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNDF, according to some embodiments. FIG. 40B illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNCX, according to some embodiments. FIG. 40C illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNCP, according to some embodiments. FIG.40D illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNWM, according to some embodiments. FIG. 40E illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNWP, according to some embodiments. FIG. 40F illustrates a UV-vis spectrum of a nanocellulose sheet derived from CNDP, according to some embodiments.

[0235] FIGS. 41A-B illustrate SEM images of the surface of a CNDP sheet prior to mechanical analysis, according to some embodiments. FIGS. 42A-B illustrate SEM images of the surface and a cross-section of a CNDP sheet after mechanical analysis, according to some embodiments. FIG. 43A illustrates an SEM image of the surface of a CNWM sheet before mechanical testing, according to some embodiments. FIG. 43B illustrates an SEM image of the surface of a CNWM sheet after mechanical testing, according to some embodiments. FIGS. 44A-B illustrate SEM images of the surface of a CNDP sheet before mechanical testing, according to some embodiments. FIGS. 44C-E illustrate SEM images of a cross-section of a CNDP sheet before mechanical testing, according to some embodiments. FIGS. 45A-B illustrate SEM images of the surface and a cross-section, respectively, of a CNDP sheet after mechanical testing, according to some embodiments.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0236] Most samples exhibited primarily elastic deformation until failure at strains below 1.5%, typical of nanocellulosic materials, whereas CNWP sheets displayed extended plastic deformation ranging from over 5% to as high as 16% in some cases. Ultimate tensile strength (UTS) was highest for CNWP and CNCX sheets (>50 MPa), followed by CNCP, CNDF, and CNWM (-22-28 MPa), while CNDP sheets exhibited the lowest strength (-5 MPa). CNDP sheets also showed moderate strain values (-2%), likely associated with macro-scale wrinkles in the sheets; once these wrinkles straightened under load, fracture occurred rapidly, reflecting weak intrinsic bonding within the CNDP nanofibril network. Strength trends correlated partly with crystallinity. CNWP, the most crystalline, exhibited moderate stiffness (E - 3300 MPa), lower than CNCX and CNCP (E - 5500 MPa and 3600 MPa, respectively), indicating that multiple micro-scale phenomena influence overall mechanical behavior. SEM and gelation analysis showed that CNWP cellulose nanofibrils are highly fibrillated with a low gelling point, enabling strong inter-fibral entanglement, consistent with rheological measurements indicating a stable, elastic-dominant gel network capable of efficient stress dissipation. Conversely, poor mechanics in CNDP correlate with its low crystallinity, partial fibrillation observed in SEM, and high levels of residual phenolics that interfere with inter-fibral hydrogen bonding, reducing structural integrity.

[0237] To benchmark the prepared hydrogels and mitigate variability due to preparation or measurement methods, a wood-derived cellulose nanofibril sheet was also prepared and tested. This reference material exhibited an ultimate tensile strength of approximately 65 MPa, a strain at break of about 8%, and a modulus of roughly 3300 MPa, demonstrating that non- wood cellulose nanofibril sheets — particularly those from CNWP and CNCX — achieved comparable mechanics despite being produced through substantially milder processes.

[0238] While the embodiment has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the embodiment. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the embodiment without departing from the essential scope thereof. Therefore, it is intended that the embodiment not be limited to the particular embodiment(s) disclosed, but that the embodiment will include all embodiments falling within the scope of the appended claims.Discussion of Possible EmbodimentsClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0239] The following are non-exclusive descriptions of possible embodiments of the present invention.

[0240] According to one aspect, a method of producing cellulose nanofibrils from plant biomass, comprising providing a plant biomass having less than 15 wt% lignin; contacting the plant biomass with an aqueous medium at a temperature in a range of 20-100 °C to produce a deconstructed plant biomass and a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed plant biomass; and mechanically processing the cellulose-rich fraction to form cellulose nanofibrils having an average diameter in a range of 2-200 nm.

[0241] The method of the preceding paragraph can optionally include, additionally and / or alternatively any, one or more of the following features / steps, configurations and / or additional components.

[0242] For example, the method may further include wherein the plant biomass has less than 14 wt% lignin.

[0243] For example, the method may further include wherein the plant biomass has less than 13 wt% lignin.

[0244] For example, the method may further comprise dispersing the cellulose nanofibrils in water to form a nanocellulose gel.

[0245] For example, the method may further include wherein the nanocellulose gel has a solids content of less than 2.0 wt% and is self-supporting as determined by a tube inversion assay.

[0246] For example, the method may further comprise repeating contacting and separating steps one or more times prior to processing.

[0247] For example, the method may further include wherein the plant biomass is tissue of one or more fruits and vegetables.

[0248] For example, the method may further include wherein the plant biomass comprises parenchymatous tissue.

[0249] For example, the method may further comprise one or more of alkali washing the plant biomass and bleaching the plant biomass prior to contacting.

[0250] For example, the method may further include wherein separating comprises centrifuging the deconstructed plant biomass to obtain the cellulose-rich fraction.

[0251] According to another aspect, a plant growth substrate comprising an aqueous nanocellulose gel, the nanocellulose gel comprising water and cellulose nanofibrils having anClient Docket No. 2025-011-02B&A Docket No. 4105.126PCT1average diameter in a range of 2-200 nm dispersed therein, the cellulose nanofibrils being obtainable by a method comprising providing a plant biomass having less than 15 wt% lignin; contacting the plant biomass with an aqueous medium comprising water at a temperature in a range of 20-100 °C to deconstruct the biomass and form a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed biomass; and processing the cellulose-rich fraction in water to produce the cellulose nanofibrils.

[0252] The plant growth substrate of the preceding paragraph can optionally include, additionally and / or alternatively any, one or more of the following features / steps, configurations and / or additional components.

[0253] For example, the plant growth substrate may further include wherein the plant growth substrate is configured for use in an indoor farming system selected from hydroponic and aeroponic cultivation systems.

[0254] For example, the plant growth substrate may further include wherein the indoor farming system is an aeroponic system.

[0255] For example, the plant growth substrate may further include wherein the nanocellulose gel is self-supporting as determined by a tube inversion assay at a cellulose nanofibril solids content of less than or equal to 2.0 wt%.

[0256] For example, the plant growth substrate may further include wherein the plant biomass comprises tissue of one or more fruits and vegetables.

[0257] For example, the plant growth substrate may further include wherein the plant biomass comprises tissue selected from carrot periderm, carrot xylem, watermelon mesocarp, watermelon pericarp, date fruit, date pomace, pineapple mesocarp, and combinations thereof.

[0258] For example, the plant growth substrate may further comprise a microbial inoculant comprising Trichoderma dispersed within the nanocellulose gel.

[0259] For example, the plant growth substrate may further include wherein the plant growth substrate is formulated for growing microgreens.

[0260] For example, the plant growth substrate may further include wherein microgreens cultivated on the plant growth substrate and subsequently stored under controlled temperature and humidity exhibit delayed wilting relative to microgreens cultivated on a cellulose pulp-based substrate under comparable conditions.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1

[0261] For example, the plant growth substrate may further include wherein the cellulose nanofibrils are obtainable by a method further comprising repeating contacting and separating steps one or more times prior to processing.

Claims

Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT1CLAIMS1. A method of producing cellulose nanofibrils from plant biomass, comprising:providing a plant biomass having less than 15 wt% lignin;contacting the plant biomass with an aqueous medium at a temperature in a range of 20- 100 °C to produce a deconstructed plant biomass and a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed plant biomass; and mechanically processing the cellulose-rich fraction to form cellulose nanofibrils having an average diameter in a range of 2-200 nm.

2. The method of claim 1, wherein the plant biomass has less than 14 wt% lignin.

3. The method of claim 2, wherein the plant biomass has less than 13 wt% lignin.

4. The method of claim 1, further comprising dispersing the cellulose nanofibrils in water to form a nanocellulose gel.

5. The method of claim 4, wherein the nanocellulose gel has a solids content of less than 2.0 wt% and is self-supporting as determined by a tube inversion assay.

6. The method of claim 1, further comprising repeating contacting and separating steps one or more times prior to processing.

7. The method of claim 1, wherein the plant biomass is tissue of one or more fruits and vegetables.

8. The method of claim 1, wherein the plant biomass comprises parenchymatous tissue.

9. The method of claim 1 , further comprising one or more of alkali washing the plant biomass and bleaching the plant biomass prior to contacting.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT110. The method of claim 1, wherein separating comprises centrifuging the deconstructed plant biomass to obtain the cellulose-rich fraction.

11. A plant growth substrate comprising an aqueous nanocellulose gel, the nanocellulose gel comprising water and cellulose nanofibrils having an average diameter in a range of 2-200 nm dispersed therein, the cellulose nanofibrils being obtainable by a method comprising:providing a plant biomass having less than 15 wt% lignin;contacting the plant biomass with an aqueous medium comprising water at a temperature in a range of 20-100 °C to deconstruct the biomass and form a cellulose-rich fraction; separating the cellulose-rich fraction from the deconstructed biomass; and processing the cellulose-rich fraction in water to produce the cellulose nanofibrils.

12. The plant growth substrate of claim 11, configured for use in an indoor farming system selected from hydroponic and aeroponic cultivation systems.

13. The plant growth substrate of claim 12, wherein the indoor farming system is an aeroponic system.

14. The plant growth substrate of claim 11, wherein the nanocellulose gel is self-supporting as determined by a tube inversion assay at a cellulose nanofibril solids content of less than or equal to 2.0 wt%.

15. The plant growth substrate of claim 11 , wherein the plant biomass comprises tissue of one or more fruits and vegetables.

16. The plant growth substrate of claim 11, wherein the plant biomass comprises tissue selected from carrot periderm, carrot xylem, watermelon mesocarp, watermelon pericarp, date fruit, date pomace, pineapple mesocarp, and combinations thereof.Client Docket No. 2025-011-02B&A Docket No. 4105.126PCT117. The plant growth substrate of claim 11, further comprising a microbial inoculant comprising Trichoderma dispersed within the nanocellulose gel.

18. The plant growth substrate of claim 11 , wherein the plant growth substrate is formulated for growing microgreens.

19. The plant growth substrate of claim 11, wherein microgreens cultivated on the plant growth substrate and subsequently stored under controlled temperature and humidity exhibit delayed wilting relative to microgreens cultivated on a cellulose pulp-based substrate under comparable conditions.

20. The plant growth substrate of claim 11, wherein the cellulose nanofibrils are obtainable by a method further comprising repeating contacting and separating steps one or more times prior to processing.

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