Fermented cassava dreg and composite cassava powder granular material and preparation method thereof
Patent Information
- Application Number
- CN202611355392.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-03
- Publication Date
- 2026-11-03
AI Technical Summary
Existing cassava residue has high moisture content, is prone to spoilage, is difficult to store and transport, has poor formability, and unstable particle strength when used directly, resulting in low resource utilization efficiency.
By pretreating cassava residue and fermenting it with compound bacteria, then mixing, granulating, and drying the compound cassava flour, binder, and water in a specific ratio, a granular material with uniform particle size, suitable moisture content, and certain compressive strength is prepared.
It significantly shortens the raw material pretreatment cycle, solves the problems of high moisture content, easy spoilage, difficult storage and transportation, and poor formability of cassava residue, and realizes high-value resource utilization and continuous clean production of cassava processing by-products.
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Figure CN123023701A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of resource utilization of cassava processing by-products and preparation of granular materials, specifically to a fermented cassava residue and composite cassava flour granular material and its preparation method. Background Technology
[0002] Cassava is a commonly used plant-based raw material in starch processing, food processing, and related industries. During the crushing, screening, washing, filtration, and starch extraction processes, a large amount of cassava residue is generated. This residue contains a certain amount of starch, cellulose, hemicellulose, and soluble organic matter, and is typically characterized by high moisture content, uneven particle size, and easy perishability. Direct storage or discharge can easily lead to rancid odors, microbial growth, and organic pollution. Direct drying is energy-intensive, and the resulting material is highly dispersible and has poor flowability, making it inconvenient for storage, transportation, and continuous use. Some cassava residue may also contain residual cyanogenic glycosides, thus requiring appropriate fermentation, drying, or detection and control steps during resource utilization.
[0003] Existing technologies for utilizing cassava residue mainly include direct drying, crushing and mixing, anaerobic treatment, and single fermentation. Directly dried cassava residue powder is prone to agglomeration, resulting in insufficient particle strength and generating significant dust during transportation and feeding. When using cassava starch alone as a molding raw material, although the resulting granules have a certain degree of cohesion, drying shrinkage is significant, making it difficult to simultaneously achieve good water resistance, compressive strength, and storage stability. Furthermore, the moisture content, fiber content, and residual starch content vary considerably between different batches of cassava residue. Without proper formulation adjustment and homogenization, unstable granulation rates, large particle size deviations, and inconsistent finished product strength can easily occur. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention aims to provide a fermented cassava residue and composite cassava flour granular material and its preparation method, thereby solving the problems of high moisture content, easy spoilage, difficult storage and transportation, poor formability, and unstable particle strength when cassava residue is directly used. Another objective of this invention is to provide a method for preparing the aforementioned granular material, which involves pretreating cassava residue and fermenting it with compound bacteria, then mixing it with composite cassava flour, a binder, and water in a specific ratio, granulating, and drying in stages to obtain a granular product with relatively uniform particle size, suitable moisture content, and a certain compressive strength.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A fermented cassava residue and composite cassava flour granular material, by weight, comprises 30-55 parts fermented cassava residue, 40-65 parts composite cassava flour, 3-8 parts binder and 5-18 parts water; The composite cassava flour comprises cassava starch, cassava flour, and modified starch, with a mass ratio of 50–80:15–40:2–10. The resulting granular material has a moisture content not exceeding 12% and a particle size of 2–8 mm. The mass percentages of each component are based on the dry basis or the mass of the material after moisture content conversion before entering the mixing process. When the fermented cassava residue contains high moisture content, its moisture content should be measured first and the dry basis feed amount should be calculated to ensure consistency in the formula across different batches.
[0006] Furthermore, the fermented cassava residue is obtained by inoculating dehydrated cassava residue with a compound microbial agent for fermentation. The compound microbial agent includes at least two of lactic acid bacteria, yeast, and Bacillus, and the inoculation amount is 0.1% to 2.0% of the mass of the dehydrated cassava residue. Preferably, the compound microbial agent includes Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis, with a viable cell ratio of 1–3:1–3:1–2. Fermentation can consume some of the easily perishable soluble organic matter, improve the odor and uniformity of the material, and make the cassava residue into a material state suitable for subsequent crushing and mixing.
[0007] Furthermore, the preparation of the fermented cassava residue includes: dehydrating the cassava residue to a moisture content of 45% to 70%, adjusting the pH to 4.5 to 6.5, fermenting it at 25 to 38°C for 24 to 96 hours, and drying and pulverizing it to 20 to 60 mesh after fermentation; Preferably, cassava residue can be dehydrated by pressure filtration, screw extrusion, or centrifugal dehydration; fermentation can be carried out in fermentation tanks with stirring mechanisms, closed fermentation boxes, or fermentation vessels with temperature detection functions. During fermentation, excessively high temperatures should be avoided to prevent cell inactivation or localized drying of the material. If necessary, stirring or turning over the material slowly can ensure uniform temperature and moisture distribution.
[0008] Furthermore, the modified starch is one or more of pregelatinized cassava starch, oxidized cassava starch, hydroxypropyl cassava starch, or cross-linked cassava starch; the binder is one or more of dextrin, pregelatinized starch, sodium carboxymethyl cellulose, or sodium alginate. The modified starch is used to adjust the water absorption, gelatinization, and molding characteristics of the mixture, while the binder is used to enhance the binding force between wet particles. Specific selections can be adjusted according to the fiber content of the raw materials, equipment pressure, and target particle strength.
[0009] Furthermore, in a preferred embodiment, the granular material further includes 0.5 to 5 parts by weight of a functional additive, which is one or more of calcium carbonate, talc, lignin sulfonate, stearate, or plant fiber. The functional additive can be used to adjust the filling, lubrication, anti-blocking, demolding, or structural support properties of the granules. The compressive strength of the granular material is not less than 10 N. The compressive strength can be measured by sampling under the same moisture content and particle size conditions to reduce the influence of testing conditions on the results.
[0010] Furthermore, the present invention also provides a method for preparing the above-mentioned particulate material, comprising the following steps: S1, the cassava residue is cleaned, washed and dehydrated to obtain pretreated cassava residue; S2, add compound microbial agent to pretreated cassava residue for fermentation to obtain fermented cassava residue; S3, the fermented cassava residue is dried and pulverized to obtain fermented cassava residue powder; S4, mix fermented cassava residue powder, compound cassava powder, binder and water to obtain a mixture; S5, granulate the mixture to obtain wet granules; S6, the wet particles are dried, cooled and sieved to obtain particulate material.
[0011] The beneficial effects of this invention are as follows: Compared with traditional direct drying of cassava residue or single starch molding processes, the fermented cassava residue and composite cassava flour granules and their preparation method provided by this invention significantly shorten the raw material pretreatment cycle. At the same time, it effectively solves the technical problems of high moisture content, easy spoilage, difficult storage and transportation, poor formability, and unstable particle strength of cassava residue, enabling high-value resource utilization and continuous clean production of cassava processing by-products. Specific beneficial effects include: (1) By dehydrating, adjusting pH and fermenting with compound bacteria, the storage instability caused by easily perishable components in cassava residue is reduced, and the moisture and particle size of the raw materials are more suitable for subsequent processing. (2) By combining cassava starch, cassava flour and modified starch, the binding and shaping effect of starch, the solid filling effect of flour and the regulating effect of modified starch on water absorption and structural strength are taken into account, thereby improving the particle forming rate and particle uniformity. (3) Through the synergistic effect of binder, water conditioning and granulation pressure, the resulting granules have good integrity, reducing breakage and dust during transportation and feeding. (4) By segmented drying and finished product screening, the moisture content of the finished product can be controlled within a range of no more than 12% while avoiding excessive hardening and cracking of the particle surface, and the utilization rate of raw materials can be improved by recycling. (5) The process steps of this method are clear and the equipment is highly adaptable. It can be implemented using common dehydration, mixing, granulation, drying and screening equipment, and is suitable for continuous or intermittent utilization of cassava processing by-products. Attached Figure Description
[0012] Figure 1 This is a flowchart illustrating the composition and molding process of the particulate material of the present invention; Figure 2 This is a flowchart illustrating the inoculation process for fermented cassava residue according to the present invention. Figure 3This is a flowchart illustrating the preparation process of fermented cassava residue powder according to the present invention. Figure 4 This is a flowchart illustrating the preparation process of the composite cassava flour and binder of the present invention. Figure 5 This is a flowchart illustrating the preparation process of the functional additive-containing particulate material of the present invention. Figure 6 This is a flowchart illustrating the overall preparation process of the particulate material of this invention. Figure 7 This is a flowchart illustrating the composition and fermentation process of the compound microbial agent of the present invention. Figure 8 This is a flowchart of the cassava residue pretreatment and pH adjustment process of the present invention. Figure 9 This is a flowchart of the mixture conditioning and granulation process of the present invention; Figure 10 This is a flowchart illustrating the segmented drying, sieving, and recycling process of the particulate material according to the present invention. Detailed Implementation
[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0014] like Figures 1 to 10 As shown, the granular material preparation process of this invention includes steps such as raw material pretreatment, compound microbial fermentation, drying and pulverizing of fermented materials, compound cassava flour formulation, mixing and humidification, granulation, segmented drying, cooling, and sieving. There is a continuous material transfer relationship between each step. Buffer silos can be set up during production according to equipment capacity, but prolonged open storage of fermented cassava residue under high temperature and high humidity conditions should be avoided.
[0015] Example 1: Preparation of Fermented Cassava Residue Powder Fresh, wet cassava residue is first sieved through a 2mm mesh screen to remove stones, metal shavings, plastic pieces, wood chips, and other coarse impurities. The sieved residue is then rinsed once with clean water at a water-to-residue ratio of 1:3. After rinsing, it is dehydrated using a screw extruder to obtain pre-treated cassava residue with a moisture content of approximately 58%. The rinsing water can be recycled process water, which should be filtered and its organic load controlled according to actual conditions to avoid bringing obviously decaying materials back into the production system.
[0016] A compound microbial agent was prepared using *Lactobacillus plantarum*, *Saccharomyces cerevisiae*, and *Bacillus subtilis*, with a viable cell ratio of 2:2:1. The inoculum amount of the compound microbial agent was 0.8% of the wet mass of the pretreated cassava residue. Before inoculation, the compound microbial agent was dispersed in a small amount of clean water to form a bacterial solution, which was then sprayed into the cassava residue while being stirred at low speed to ensure uniform distribution of the bacterial solution. The pH of the material was adjusted to 5.5 by adding food-grade calcium carbonate. The material was then placed in a fermentation chamber equipped with a temperature probe and ventilation holes and fermented at 32℃ for 60 hours. During fermentation, the material was stirred every 12 hours to ensure that the temperature and moisture content were relatively uniform between the center and the edges. When the material temperature exceeded 38℃, the ambient temperature was lowered or the material was stirred to dissipate heat.
[0017] After fermentation, the material is fed into a belt dryer and dried under hot air conditions of 60-80℃ to reduce the moisture content of the fermented cassava residue to below 10%. The dried material is then pulverized using a hammer mill and sieved through a 40-mesh screen. The undersize material is used as fermented cassava residue powder; the oversize material is returned to the mill for secondary pulverization. The resulting fermented cassava residue powder should be loose, without obvious lumps or a putrid odor. If there is a risk of cyanogenic glycoside residue residue in the raw material, samples should be taken for testing after this step, and appropriate safety limit controls should be implemented according to the product's intended use.
[0018] Example 2: Preparation of Compound Tapioca Flour Cassava starch, cassava flour, and pregelatinized cassava starch were sieved separately to remove lumps and then weighed at a mass ratio of 70:25:5. Cassava starch provides basic binding and shaping properties, cassava flour increases solids content and improves the skeletal structure of the particles, and pregelatinized cassava starch increases water absorption rate and initial strength of wet particles during room temperature mixing. The three powders were added to a horizontal ribbon mixer and mixed for 10 minutes. The mixer speed was adjusted to ensure uniform flow of the powders without significant dust generation.
[0019] In other embodiments, pregelatinized cassava starch can be replaced with oxidized cassava starch, hydroxypropyl cassava starch, or cross-linked cassava starch, or a combination of two or more of these. The specific type and amount of modified starch should be determined based on the water absorption rate of the mixture, granulation pressure, particle surface condition, and end use. When oxidized cassava starch is used, the dispersibility of the material can be improved; when hydroxypropyl cassava starch is used, the structural stability under humid and hot conditions can be improved; when cross-linked cassava starch is used, the ability of the particles to retain their structure in a certain moisture environment can be enhanced.
[0020] Example 3: Preparation of particulate materials Weigh out 45 parts of fermented cassava residue powder obtained in Example 1, 50 parts of composite cassava powder obtained in Example 2, 5 parts of dextrin, and 1.5 parts of calcium carbonate by dry weight. Add the powders to a mixer and premix for 8 minutes. Then, add water by spraying to adjust the moisture content of the mixture to 24%. Keep the mixer running during the water addition process. After the water is added, continue mixing for 12 minutes to obtain a mixture with basically uniform color and moisture content. A small amount of the mixture can be clumped together when squeezed in the hand but easily dispersed when lightly touched; this serves as a simple judgment of its state before granulation. The final moisture content will still be determined by testing.
[0021] The mixture is fed into an extrusion granulator, where it is granulated using a 4mm diameter perforated plate. The material temperature is controlled between 35 and 50°C during granulation. The extruded strips are cut by a cutter to form wet granules, with a length controlled between 4 and 8mm. If the extrudate exhibits severe adhesion to the wall or breakage, the moisture content of the mixture, the dispersion of the binder, and the temperature of the perforated plate should be checked. If the granules are brittle, the mixing time can be appropriately increased, or the amount of binder can be adjusted within the limits defined in the claims.
[0022] Wet granules enter a belt dryer for segmented drying. The first drying section is set at 65℃ to slowly remove some moisture from the surface and interior of the granules; the second drying section is set at 90℃ to further reduce the moisture content of the granules. During the drying process, the granule layer thickness is kept uniform to avoid localized accumulation that results in an outer dry and inner wet layer. The dried granules then enter a cooling section, where they are cooled to near room temperature and then sieved to obtain finished granules with a particle size of 2–8 mm. The undersized fines are returned to the mixing step, while the oversized coarse materials are crushed and returned to the granulation step.
[0023] Example 4: Adjustment plan within the formula range In another embodiment, the mixture comprises 35 parts fermented cassava residue, 58 parts compound cassava flour, 4 parts sodium carboxymethyl cellulose, 12 parts water, and 2 parts lignin sulfonate. The mass ratio of cassava starch, cassava flour, and oxidized cassava starch in the compound cassava flour is 60:30:10. The fermented cassava residue uses a material with a moisture content of 52%, inoculated with *Lactobacillus plantarum* and *Saccharomyces cerevisiae* at an inoculation amount of 0.5% of the wet base material mass, and the pH is adjusted to 5.0. Fermentation is carried out at 28°C for 48 hours. The mixture is then moistened to a moisture content of 21% and granulated using a disc granulator with the disc surface temperature controlled at 30–45°C. The resulting wet granules are dried using two stages of hot air drying at 70°C and 100°C.
[0024] In another embodiment, the mixture comprises 52 parts fermented cassava residue, 42 parts compound cassava flour, 6 parts pregelatinized starch, 15 parts water, and 3 parts plant fiber. The mass ratio of cassava starch, whole cassava flour, and cross-linked cassava starch in the compound cassava flour is 75:20:5. The moisture content of the mixture is controlled at 27%, and granulation is performed using a rotary granulator at a temperature of 40–60°C to obtain wet granules with a particle size of 3–6 mm. These granules are then dried in a first stage at 55–75°C and a second stage at 80–105°C.
[0025] Process control and testing methods In this invention, the moisture content of cassava residue is calculated by weighing the sample and drying it to constant weight at 105℃; the fermentation temperature is detected using a temperature probe inserted into the material, with at least two locations tested: the center and the edge; the pH value is determined by mixing the material with deionized water at a mass ratio of 1:10, stirring thoroughly, and then taking the extract for testing. The viable count of the compound microbial agent is determined according to the conventional plate count method for the selected strain or the supplier's inspection report, and the proportion of viable counts is used as the measurement basis during mixing.
[0026] The moisture content of the finished product should be tested after cooling to avoid testing deviations caused by sampling at high temperatures. Particle size should be determined by sieving using a standard sieve with aperture sizes corresponding to 2mm and 8mm; finished particles should be retained between two sieve apertures. Particle compressive strength can be determined using a single-particle compressive strength tester. Randomly select at least 20 particles, apply axial pressure to each particle, record the maximum load at which the particle breaks, and use the average of the measured values as the batch compressive strength. Batch stability can be improved by controlling the fermentation endpoint, the moisture content of the mixture, the granulation temperature, the drying rate, and the proportion of recycled material from sieving.
[0027] Working Principle and Usage: The granular material of this invention can be metered, conveyed, or fed according to specific applications before use. After microbial action, the fermented cassava residue undergoes improved material condition. The cassava starch and modified starch in the composite cassava flour form a continuous or semi-continuous bound phase under the action of water addition and granulation pressure, coating or connecting the fermented cassava residue powder, whole cassava flour, and functional additives within the granular structure. After drying, the reduced moisture content solidifies the bound phase, forming granules with a certain compressive strength. The specific proportions of different raw materials can be adjusted within the scope defined in the claims to adapt to different equipment and applications.
[0028] Additionally, it should be noted that this invention does not require all cassava residue to use the same fermentation equipment. For small-batch production, covered fermentation tanks or fermentation boxes can be used; for continuous production, continuous spiral fermenters or multi-stage fermentation equipment can be used. The fermentation equipment should be able to perform temperature monitoring, material mixing, and necessary venting, and the parts in contact with the cassava residue should be made of corrosion-resistant materials. The granulation equipment can be selected from extrusion granulation, disc granulation, or rotary granulation methods according to the material flowability and target particle size.
[0029] Obviously, the basic principles, main features, and advantages of the present invention have been described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A fermented cassava residue and composite cassava flour granule material, characterized in that, By weight, it includes the following components: 30-55 parts fermented cassava residue, 40-65 parts compound cassava flour, 3-8 parts binder and 5-18 parts water; The composite cassava flour comprises cassava starch, cassava flour, and modified starch, wherein the mass ratio of cassava starch, cassava flour, and modified starch is 50–80:15–40:2–10; the moisture content of the granular material is not higher than 12%, and the particle size is 2–8 mm.
2. The particulate material according to claim 1, characterized in that, The fermented cassava residue is obtained by inoculating dehydrated cassava residue with a compound microbial agent for fermentation. The compound microbial agent includes at least two of lactic acid bacteria, yeast and Bacillus, and the inoculation amount is 0.1% to 2.0% of the mass of dehydrated cassava residue.
3. The particulate material according to claim 2, characterized in that, The preparation of the fermented cassava residue includes: dehydrating the cassava residue to a moisture content of 45% to 70%, adjusting the pH to 4.5 to 6.5, fermenting it at 25 to 38°C for 24 to 96 hours, and then drying and pulverizing it to 20 to 60 mesh.
4. The particulate material according to claim 1, characterized in that, The modified starch is one or more of pregelatinized cassava starch, oxidized cassava starch, hydroxypropyl cassava starch, or cross-linked cassava starch; the binder is one or more of dextrin, pregelatinized starch, sodium carboxymethyl cellulose, or sodium alginate.
5. The particulate material according to claim 1, characterized in that, The granular material further includes 0.5 to 5 parts by weight of functional additives, which are one or more of calcium carbonate, talc, lignin sulfonate, stearate, or plant fiber; the compressive strength of the granular material is not less than 10N.
6. A method for preparing the particulate material according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Remove impurities, wash and dehydrate the cassava residue to obtain pretreated cassava residue; S2. Add compound microbial agent to the pretreated cassava residue and ferment it to obtain fermented cassava residue; S3. Dry and pulverize the fermented cassava residue to obtain fermented cassava residue powder; S4. Mix the fermented cassava residue powder, compound cassava powder, binder and water to obtain a mixture; S5. Granulate the mixture to obtain wet granules; S6. The wet particles are dried, cooled, and sieved to obtain the particulate material.
7. The method according to claim 6, characterized in that, In step S2, the compound microbial agent includes Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis, with a live cell ratio of 1-3:1-3:1-2; the fermentation temperature is 25-38℃, and the fermentation time is 24-96 hours.
8. The method according to claim 6, characterized in that, In step S1, the cassava residue is passed through a sieve with a mesh size of 1-3 mm to remove coarse impurities, and then dehydrated to a moisture content of 45%-70% by pressure filtration or screw extrusion; in step S2, the pH value of the system is adjusted to 4.5-6.5 by adding one or more of calcium carbonate, sodium bicarbonate or food-grade organic acids.
9. The method according to claim 6, characterized in that, In step S4, the mixing time is 5 to 20 minutes, and the moisture content of the mixture is 18% to 30%. In step S5, granulation is carried out using a disc granulator, extrusion granulator, or rotary granulator, and the granulation temperature is 25 to 60°C.
10. The method according to claim 6, characterized in that, Step S6 employs segmented drying, with the first stage drying temperature at 50–75°C and the second stage drying temperature at 75–105°C, drying until the particle moisture content is no higher than 12%. Materials with a particle size less than 2 mm obtained from sieving are returned to step S4 for remixing and granulation, while materials with a particle size greater than 8 mm are crushed and returned to step S5 for regranulation.