Preparation and processing method of coconut-based metaplasm coffee

Abstract

The invention discloses a preparation and processing method of coconut-based metagen coffee, and belongs to the field of coffee processing. Coconut water is fermented by lactobacillus plantarum HNU531, a drying aid beta-cyclodextrin is added, and freeze drying is performed to prepare the coconut-based metagen, and the coconut-based metagen has good solubility. By additionally adding the coconut-based metagen into the instant coffee, the contents of gallic acid, isomaltose, trehalose and the like which are beneficial to a human body in the coffee can be increased. The sour taste and bitter taste of the coffee can be reduced, and the quality of the coffee is improved.

Description

Technical Field

[0001] This invention relates to a method for preparing and processing coconut-based post-biotic coffee, belonging to the field of coffee processing technology. Background Technology

[0002] Coffee is a widely consumed non-alcoholic beverage, its flavor primarily composed of a combination of sensory attributes such as bitterness, acidity, and sweetness. With the diversification of consumer demands, the market has placed higher requirements on coffee products with harmonious flavors, lower stimulant levels, and certain health benefits. How to improve issues such as excessive bitterness and insufficient acidity / sweetness while maintaining the characteristic flavor of coffee has become an important research direction in the coffee processing field. Existing technologies for improving coffee flavor mainly include controlling raw material quality, altering roasting levels, optimizing extraction conditions, and flavor adjustment through fermentation or blending. Among these, microbial fermentation is considered a crucial means of influencing coffee flavor composition, as it can affect the balance of acidity, sweetness, and bitterness by altering the composition of organic acids, sugars, and their precursors. However, existing fermentation processes are mostly concentrated at the fresh coffee cherry or green bean stage, resulting in batch-specific processes with limited controllability, and insufficient ability to specifically adjust bitterness and enhance acidity / sweetness in the final beverage.

[0003] Furthermore, to impart certain health attributes to coffee products, some studies have attempted to introduce probiotics or their fermentation products into the coffee system. However, active probiotics are quite sensitive to processing conditions such as temperature and pH, exhibiting poor stability during coffee preparation and making it difficult to guarantee consistent product quality. Simultaneously, directly adding probiotics or fermentation broth can easily interfere with the original flavor of the coffee, affecting its taste harmony. Epigenetics, as metabolites and cell components formed during microbial fermentation, possess characteristics such as good heat resistance and high stability, enabling them to adapt to food processing conditions and gradually gaining attention in the functional food field. However, in current technologies, epigenetics are mainly used in dairy products or fruit and vegetable beverage systems, with limited application in coffee products, particularly lacking a technical solution that can simultaneously achieve flavor regulation and certain functional activities. Coconut-based raw materials are rich in polysaccharides, lipids, and various fermentable substrates, possessing a certain natural sweetness and mild flavor characteristics. Current technologies mostly use them as beverage bases or flavoring ingredients, and a mature method for preparing epigenetics from coconut substrate fermentation and further using them in coffee processing has not yet been developed. Existing blends of coconut and coffee are mostly limited to simple mixing, with limited effect on reducing coffee bitterness and enhancing its sweet and sour flavor.

[0004] Therefore, it is still necessary to provide a new method for preparing and processing coconut-based post-biotic coffee, which can effectively reduce the bitterness of coffee and improve the balance of acidity and sweetness of coffee while ensuring processing adaptability and product stability, so as to meet the needs of flavor quality and product application. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing and processing coconut-based post-biotic coffee. The method involves preparing a stable post-biotic by fermenting a coconut matrix with a specific Lactobacillus plantarum, and then applying it to coffee products to reduce coffee bitterness, improve coffee acidity and sweetness, and enhance the overall sensory quality.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a strain of Lactobacillus plantarum ( Lactiplantibacillus plantarum HNU531, this strain was deposited at the Guangdong Provincial Microbial Culture Collection Center on December 15, 2025, with the culture collection number GDMCC No: 67494.

[0007] This invention also provides a coconut-based epigenetic agent, the preparation method of which includes the following steps: After filtering coconut water through gauze, third-generation Lactobacillus plantarum HNU531 was inoculated into the coconut water for fermentation. After fermentation, the fermentation liquid was inactivated to obtain coconut-based postbiotic fermentation product.

[0008] Preferably, *Lactobacillus plantarum* HNU531 is inoculated into MRS liquid medium and cultured at 37°C for 24 h; 200 µL of the bacterial culture is passaged for 24 h, and then passaged again for 24 h to obtain the third generation; the third generation bacterial culture is centrifuged at 4000 r / min for 5 min, the supernatant is discarded, and the culture is resuspended in physiological saline, then added to coconut water, and fermented at 37°C for 24 h; after fermentation, 10%–30% of the drying agent β-cyclodextrin is added, and coconut-based postbiotics are prepared by freeze drying.

[0009] Preferably, Lactobacillus plantarum HNU531 is used in a 10 8 ~10 10 The inoculum was inoculated into coconut water at a dose of CFU / mL.

[0010] Preferably, the fermentation broth is inactivated by treatment at 90–110°C for 10–20 min.

[0011] The present invention also provides products containing the aforementioned Lactobacillus plantarum HNU531 or the aforementioned metabiotic.

[0012] In one embodiment, the product includes food, medicine, or health products.

[0013] In one embodiment, the food includes beverages.

[0014] The present invention also provides a method for improving coffee quality by mixing coffee powder with the post-genetic agent and then brewing it.

[0015] In one embodiment, the coconut-based post-biotic is mixed with coffee powder at an addition ratio of 5% to 20% to prepare a coconut-based post-biotic coffee product.

[0016] In one embodiment, the coconut-based post-biotic coffee, while preserving the basic flavor characteristics of coffee, reduces the bitterness of coffee and enhances its acidity and sweetness, thereby improving the overall sensory evaluation.

[0017] In one embodiment, improving coffee quality includes increasing the content of gallic acid, isomaltose, and / or trehalose in the coffee.

[0018] The present invention also provides the application of the aforementioned Lactobacillus plantarum HNU531 and / or its postgenes in the preparation of coconut-based coffee.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The coconut-based post-biotic prepared by this invention, when applied to coffee, can effectively reduce the bitterness of coffee without significantly damaging its original flavor characteristics, while enhancing its acidity and sweetness, resulting in a more harmonious flavor and significantly improved sensory quality.

[0020] This invention uses coconut substrate as a fermentation substrate to prepare postbiotics. Coconut water is rich in sugars, various amino acids and minerals, making it suitable as a natural culture medium for the growth and metabolism of Lactobacillus plantarum, which is beneficial for obtaining postbiotic fermentation products with stable composition.

[0021] This invention uses postbiotics in coffee products, avoiding the problem of poor stability of live probiotics during coffee processing and storage. Postbiotics have good heat resistance and strong processing adaptability, which helps to improve the consistency and stability of product quality.

[0022] Preservation of biological materials: Lactobacillus plantarum ( Lactiplantibacillus plantarum HNU531, taxonomically named Lactiplantibacillus plantarum It was deposited on December 15, 2025 at the Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC No: 67494. Attached Figure Description

[0023] Figure 1 Electronic tongue changes in coffee and coconut-based post-biotic coffee.

[0024] Figure 2 Cluster analysis diagram of metabolites from coffee and coconut-based post-biotic coffee. Detailed Implementation

[0025] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0026] The coffee powder used in the following examples was purchased from Hainan Nongken Mushan Coffee Co., Ltd. Other commercially available coffee powders or coffee powder obtained by grinding commercially available coffee beans can also achieve the effects of the present invention.

[0027] Example 1: Lactobacillus plantarum ( Lactiplantibacillus plantarum Screening and identification of HNU531 This study collected fecal samples from 50-year-old men in Chang'an Village, Changfeng Town, Wanning City, Hainan Province, and prepared 10-fold dilution gradients using a 10-fold dilution method. -1 -10 -5 100 μL of each diluted sample solution was spread onto MRS agar medium and anaerobically incubated at 37°C for 48 h. After multiple isolation, purification, and culture cycles, and after identifying the morphology of Gram-stained bacteria under a microscope, samples with a single morphology were retained, and samples containing other bacteria were discarded.

[0028] Identification of isolates: DNA was extracted from the isolates according to the kit. PCR was then performed to amplify the 16S rRNA gene of each sample. The amplified products were then electrophoresed using 0.8% agarose gel electrophoresis. Sequencing was performed by Qingdao Pengxiang Biotechnology.

[0029] The sequence of the isolate was compared with NCBI, and the highest Query cover and Ident information in the output results were selected as the species-level identification result of the isolate, which was identified as Lactobacillus plantarum and later named Lactobacillus plantarum HNU531.

[0030] The plant lactobacillus ( Lactiplantibacillus plantarum HNU531 colonies were incubated on agar medium at 37°C for 24 h. The colonies were milky white, 0.1-0.2 cm in diameter, with a smooth, moist, raised surface and neat edges. Under an optical microscope, they appeared as rods.

[0031] The method for determining the acid tolerance of the strain is as follows: Adjust the pH of the MRS broth medium to 2.0 and 3.0 respectively using 1 mol / L HCl. Then, the activated strain is added at a ratio of 10... 10CFU / mL inoculum was inoculated into MRS broth medium at different pH values ​​and incubated at 37℃ for 4 h. After 10-fold serial dilutions, the inoculum was plated onto MRS agar medium, and the viable cell count was determined to calculate the survival rate and characterize the strain's tolerance. The method for determining the strain's bile salt tolerance is as follows: the activated strain was inoculated at 10... 10 Inoculated at a CFU / mL inoculum into MRS broth containing 0.3% ox bile salts, incubated at 37°C for 4 h, and then serially diluted 10-fold before being plated onto MRS agar. The viable bacterial count was determined, and the survival rate was calculated to characterize the strain's tolerance. Experiments revealed that *Lactobacillus plantarum* (… Lactiplantibacillus plantarum HNU531 exhibits good tolerance, with 38% tolerance at pH 2, 83% tolerance at pH 3, and 14% tolerance to bile salts.

[0032] Example 2: Preparation of coconut-based post-biotic coffee In this embodiment, *Lactobacillus plantarum* (…) was selected. Lactiplantibacillus plantarum HNU531, this strain was deposited at the Guangdong Provincial Microbial Culture Collection Center on December 15, 2025, with the culture collection number GDMCC No: 67494.

[0033] Lactobacillus plantarum HNU531 was inoculated into MRS liquid medium and cultured at 37℃ for 24 h to obtain the first-generation bacterial culture. 200 µL of the first-generation culture was inoculated into fresh MRS liquid medium and cultured at 37℃ for 24 h to obtain the second-generation bacterial culture. Another 200 µL of the second-generation culture was inoculated into fresh MRS liquid medium and cultured at 37℃ for 24 h to obtain the third-generation bacterial culture, which was then used for further processing. Fresh coconut water was filtered through gauze to remove impurities, resulting in clear coconut water. The third-generation Lactobacillus plantarum HNU531 bacterial culture was centrifuged at 4000 r / min for 5 min, the supernatant was discarded, and the cells were resuspended in physiological saline. The resuspended bacterial culture was inoculated into the filtered coconut water at an inoculation rate of 3% (v / v), with an initial inoculation volume of 1×10⁻⁶. 9 Fermentation was carried out at 37℃ for 24 h using CFU / mL to obtain a fermentation broth. After fermentation, the broth was placed in an autoclave and treated at 100℃ for 15 min to inactivate the fermentation broth, yielding a coconut-based post-biotic fermentation broth. Subsequently, 10% β-cyclodextrin was added to the coconut-based post-biotic fermentation broth, and after thorough mixing, it was freeze-dried to obtain coconut-based post-biotic freeze-dried powder. Coffee powder was used as the raw material, and the coconut-based post-biotic freeze-dried powder was added to it at a ratio of 10% of the coffee powder mass. The mixture was thoroughly mixed using conventional methods to prepare a coconut-based post-biotic coffee product.

[0034] Example 3: Preparation of coconut-based post-biotic coffee In this embodiment, *Lactobacillus plantarum* (…) was selected. Lactiplantibacillus plantarum HNU531, this strain was deposited at the Guangdong Provincial Microbial Culture Collection Center on December 15, 2025, with the culture collection number GDMCC No: 67494.

[0035] Lactobacillus plantarum HNU531 was inoculated into MRS liquid medium and cultured at 37℃ for 24 h to obtain the first-generation bacterial culture. 200 µL of the first-generation culture was inoculated into fresh MRS liquid medium and cultured at 37℃ for 24 h to obtain the second-generation bacterial culture. Another 200 µL of the second-generation culture was inoculated into fresh MRS liquid medium and cultured at 37℃ for 24 h to obtain the third-generation bacterial culture, which was then used for further processing. Fresh coconut water was filtered through gauze to remove impurities, resulting in clear coconut water. The third-generation Lactobacillus plantarum HNU531 bacterial culture was centrifuged at 4000 r / min for 5 min, the supernatant was discarded, and the cells were resuspended in physiological saline. The resuspended bacterial culture was inoculated into the filtered coconut water at an inoculation rate of 4% (v / v), with an initial inoculation volume of 10 μL. 8 Fermentation was carried out at 37℃ for 24 h using CFU / mL to obtain the fermentation broth. After fermentation, the broth was placed in an autoclave and treated at 110℃ for 10 min to inactivate the fermentation broth, resulting in a coconut-based post-biotic fermentation broth. Subsequently, 15% β-cyclodextrin was added to the coconut-based post-biotic fermentation broth, and after thorough mixing, it was freeze-dried to obtain coconut-based post-biotic freeze-dried powder. Coffee powder was used as the raw material, and the coconut-based post-biotic freeze-dried powder was added to it at a ratio of 15% by weight of the coffee powder. The mixture was thoroughly mixed using conventional methods to prepare the coconut-based post-biotic coffee product.

[0036] Example 4: Quality Analysis of Coconut-Based Post-Activated Coffee Sensory evaluation: The review panel consisted of 20 people. Fifteen sensory members, aged 30 and above, conducted sensory evaluations of coconut-based post-biotic coffee products. Evaluation indicators included: mouthfeel, flavor, body, aftertaste, texture, acidity, and overall acceptability. Each coffee sample was evaluated in triplicate according to SCAA standards. The standard brewing method for the sampled coffee was: using 90-95℃ hot water, brewed slowly. Evaluators scored each sample according to Table 1 and recorded the evaluation results.

[0037] Table 1 Sensory Evaluation Scoring Table

[0038] The results are shown in Table 2. The mouthfeel, flavor, acidity, and total score of coconut-based post-biotic coffee were significantly higher than those of regular coffee. Adding coconut-based post-biotics improved the mouthfeel by 63.9%, flavor by 83.8%, and acidity by 71.1%. From a sensory perspective, adding coconut-based post-biotics to coffee significantly improves its flavor, mouthfeel, and acidity, greatly enhancing its quality.

[0039] Table 2 Sensory Evaluation of Coffee and Coconut-Based Post-Oxidant Coffee

[0040] Electronic tongue analysis: Flavor characteristics of coffee and coconut-based post-biotic coffee were detected using an Alpha MOS electronic tongue. After centrifugation, the supernatant of the coconut-based post-biotic coffee sample was retained and filtered through a 0.45 μm filter. The sample was diluted 1:25, and 25 mL of the diluted sample was placed in a sample cup. Electrode cleaning solution, calibration solution, and reference solution were placed in sequence. The electronic tongue detection time was 120 s, and the cleaning time was 10 s.

[0041] The results are as follows Figure 1 As shown, the addition of coconut-based post-biotics had little effect on the umami, saltiness, and complex flavor A / B of coffee. However, the acidity of coconut-based post-biotic coffee was significantly higher than that of regular coffee, its sweetness was slightly higher, and its bitterness was significantly lower, which is consistent with the sensory evaluation results in Table 1 above. This further demonstrates that the addition of coconut-based post-biotics can enhance the acidity of coffee and suppress its bitterness, thereby improving the quality of coffee.

[0042] Volatile substances: A certain amount of coffee and coconut-based post-biotic coffee samples were added to the extract containing internal standards, vortexed, and extracted in an ice-water bath. After standing (-20℃, 30 min), the mixture was centrifuged at high speed. The supernatant was transferred to a derivatization vial, and methoxyamine hydrochloride pyridine solution was added for oxime reaction (90 min). Subsequently, derivatization reagent was added and reacted (70℃, 60 min). GC-MS non-target metabolomics analysis of the samples was performed using a TRACE 1610 GC-Orbitrap Exploris high-resolution gas chromatography-mass spectrometry system (Thermo Fisher Scientific). The injection volume was 1 µL, and the split ratio was set to 10:1. The samples were separated by a TG-5 SILMS capillary column (30 m × 0.25 mm × 0.25 µm, Thermo 26096-1420) before being detected by mass spectrometry. The raw GC / MS data were preprocessed using software (Compound Discovery 3.3 SP3), including ion peak filtering, deconvolution, peak matching, and feature extraction, before being used for qualitative and quantitative analysis of metabolites in the metabolomics.

[0043] The results are as followsFigure 2 As shown, the addition of coconut-based post-biotics significantly increased the content of various beneficial components, such as gallic acid, isomaltose, and trehalose. Among these, gallic acid possesses excellent antioxidant, anti-inflammatory, and antibacterial properties, making it a natural antioxidant; isomaltose is a low-GI food, while trehalose also exhibits certain antioxidant and anti-aging functions. These results indicate that coconut-based post-biotic coffee also possesses certain functional properties.

[0044] Obviously, the above embodiments of the present invention are merely examples to illustrate the present invention more clearly, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all implementation methods here. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A strain of Lactobacillus plantarum ( Lactiplantibacillus plantarum HNU531, characterized in that, It was deposited at the Guangdong Provincial Center for Microbial Culture Collection on December 15, 2025, with the culture collection number GDMCC No: 67494.

2. A metabiotic containing *Lactobacillus plantarum* HNU531 as described in claim 1, characterized in that, It is obtained by inoculating the Lactobacillus plantarum HNU531 into coconut water for fermentation and then inactivating it.

3. The epigenetic agent according to claim 2, characterized in that, Inoculate 10g in coconut water 8 ~10 10 CFU / mL Lactobacillus plantarum HNU531 was fermented at 35-40 ℃ for 12-48 h. After inactivation, 10%-30% β-cyclodextrin was added, and the mixture was freeze-dried to obtain the post-biotic.

4. A product containing Lactobacillus plantarum HNU531 as described in claim 1 or a metabiotic as described in claim 2 or 3.

5. The product according to claim 4, characterized in that, The products include food, medicine, or health products.

6. The product according to claim 5, characterized in that, The food includes beverages.

7. A method for improving coffee quality, characterized in that, The coffee powder is mixed with the post-biotic as described in claim 2 or 3 and then brewed.

8. The method according to claim 7, characterized in that, Improving coffee quality includes reducing bitterness, increasing acidity, increasing sweetness, and / or improving mouthfeel.

9. The method according to claim 7, characterized in that, Improving coffee quality includes increasing the content of gallic acid, isomaltose, and / or trehalose in the coffee.

10. The use of Lactobacillus plantarum HNU531 and / or its postgenes as described in claim 1 in the preparation of coconut-based coffee.

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