Preparation method of fermenting drink of chayote

Abstract

This invention belongs to the field of food processing technology, specifically relating to a method for preparing a fermented chayote beverage. The method utilizes a dual-strain fermentation process using *Saccharomyces cerevisiae* and *Lactobacillus plantarum*. The resulting fermented chayote beverage is yellow-green in color, glossy, with a uniform liquid, free of impurities, possessing the delicate aroma of chayote, a harmonious flavor, a balanced sweet and sour taste, a refreshing and smooth texture, and a pure flavor. Furthermore, experiments have demonstrated that the fermented chayote beverage prepared by this invention exhibits high SOD enzyme activity, strong DPPH and ABTS free radical scavenging ability, and high vitamin C content, demonstrating significant antioxidant activity. It is a relatively ideal functional chayote beverage, providing a theoretical basis and technical support for the industrial production of chayote.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and specifically relates to a method for preparing a fermented chayote beverage. Background Technology

[0002] Chayote ( Sechium edule ( Jacq. ) Swartz Chayote, a perennial vine belonging to the genus Chayote in the Cucurbitaceae family, originated in Central America and Mexico. Introduced to China in the 19th century, it is widely cultivated in southern regions such as Fujian and Yunnan. The fruit is pear-shaped or oblate, with a light green skin and crisp, juicy flesh, possessing characteristics of both a vegetable and a fruit. Studies have shown that chayote has a water content of over 90%, only 19 kcal / 100g, and is rich in dietary fiber, making it a typical low-sugar, low-fat healthy food. Chayote is rich in minerals, with high levels of potassium, calcium, and magnesium, and low sodium. This high-potassium, low-sodium characteristic helps regulate blood pressure balance, while dietary fiber promotes intestinal peristalsis and improves metabolic syndrome. Furthermore, chayote extract has significant antioxidant activity, showing great potential in delaying aging and preventing chronic diseases.

[0003] Currently, the use of chayote has expanded from fresh consumption to diversified processing fields. In the food industry, its pulp can be directly processed into preserves or compound jams; in the pharmaceutical field, extracts from chayote fruit, tender shoots, and tubers are used to develop functional drugs. For example, patent document CN1068253A discloses a method for producing chayote preserves using a sugar-preserving and honey-processing technique. This method uses chayote as the main raw material, pre-treats it, and then combines it with fruits that have rich aroma and color, using a sugar-preserving and honey-processing technique to produce chayote preserves with natural color, aroma, and flavor. This method is simple and easy to implement, has low production costs, and produces high-quality products, providing a new and abundant source of raw materials for preserve production.

[0004] Patent document CN115227751A discloses a method for preparing chayote extract. The method includes the following steps: S1, adding water and a pretreatment agent to chayote powder to obtain a pretreatment mixture; S2, adding a stabilizer and cellulase to the pretreatment mixture, followed by centrifugation to obtain a crude extract; S3, concentrating, purifying, and drying the crude extract to obtain chayote extract. This method solves the problems of low flavonoid content and poor stability in chayote extracts in the prior art.

[0005] However, the industrialization of chayote still faces multiple bottlenecks. For example, the short shelf life of chayote restricts long-distance transportation and market expansion. The preparation of chayote extracts still suffers from low content of active ingredients and poor stability. Therefore, researching and developing an effective method to solve the problems of easy spoilage and high storage and transportation losses of fresh chayote, and to significantly extend its shelf life, remains an urgent challenge. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing a fermented chayote beverage. This invention utilizes *Saccharomyces cerevisiae* and *Lactobacillus plantarum* for dual-strain fermentation to produce the beverage. The invention systematically analyzes the effects of key process parameters—initial sugar content, fermentation temperature, fermentation time, and inoculum size—on the sensory quality and physicochemical properties of the chayote pulp enzyme. Furthermore, this invention investigates the changes in the nutritional components of the chayote pulp enzyme during fermentation, elucidating the nutritional composition patterns during the fermentation process, and providing a theoretical basis and technical support for the industrial production of chayote pulp enzyme.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for preparing a fermented chayote beverage, comprising the following steps: Step S1: Wash the chayote, peel it, cut it into chunks, and deactivate the enzymes to obtain chayote chunks; Step S2: Juice the chayote chunks obtained in step S1, filter, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize, and obtain chayote juice. Step S3: Add white sugar to the chayote juice obtained in step S2. The amount of white sugar added is 6-8% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast culture, introduce oxygen, and ferment at a temperature of 27-33 ℃ for 10-20 h. After fermentation, inoculate with Lactobacillus plantarum culture, introduce oxygen for 1-3 h, seal, and ferment at a temperature of 35-39 ℃ for 10-20 h. Centrifuge, take the supernatant to obtain chayote pulp enzyme, sterilize, and package to obtain the product.

[0008] The strain of *Saccharomyces cerevisiae* used in this invention is SMHCC D24918, Latin name: Saccharomyces cerevisiae The strain of *Lactobacillus plantarum* used in this invention is numbered SMHCC D16021, with the Latin name: Lactobacillus plantarum .

[0009] Furthermore, the enzyme inactivation treatment in step S1 is blanching in boiling water for 10-15 seconds.

[0010] Furthermore, in step S3, the inoculation amount of the brewer's yeast liquid is 3-7% of the total volume of the chayote juice.

[0011] Furthermore, the viable count of the brewer's yeast culture is 1×10⁻⁶. 10 ~1×10 12 cfu / mL.

[0012] Furthermore, in step S3, the inoculation amount of Lactobacillus plantarum solution is 3-7% of the total volume of chayote juice.

[0013] Furthermore, the viable count of the *Lactobacillus plantarum* bacterial solution is 2.5 × 10⁻⁶. 9 ~2.5×10 11 cfu / mL.

[0014] Furthermore, step S3 also includes adding purslane juice to the chayote juice. The purslane juice is obtained by juicing purslane, filtering, taking the filtrate, and homogenizing the filtrate.

[0015] Furthermore, in step S3, the volume ratio of chayote juice to purslane juice is 1:(0.2~0.6).

[0016] Secondly, the present invention also claims protection for the chayote fermented beverage prepared by the method described above.

[0017] In addition, the present invention also provides the application of the chayote fermented beverage in the preparation of products for weight control or blood lipid improvement.

[0018] This invention uses sensory evaluation to investigate the optimal fermentation process for chayote juice, considering factors such as fermentation time, fermentation temperature, inoculum size of *Saccharomyces cerevisiae* and *Lactobacillus plantarum*, and initial sugar content. The order of influence of each factor on the sensory evaluation of the chayote juice pulp enzyme is: fermentation time > inoculum size > initial sugar content > fermentation temperature. The optimal fermentation conditions are: initial sugar content adjusted to 7%, fermentation with 6% *Saccharomyces cerevisiae* for 14 hours, followed by fermentation with 6% *Lactobacillus plantarum* for another 14 hours. The fermentation temperature for the first stage with *Saccharomyces cerevisiae* was 31℃, and the fermentation temperature for the second stage with *Lactobacillus plantarum* and *Saccharomyces cerevisiae* was 38℃. Under these optimal fermentation conditions, the chayote juice pulp enzyme achieved the highest sensory evaluation score of 84.6, with a total sugar content of 48.23±1.24 mg / mL, a reducing sugar content of 27.63±1.33 mg / mL, and a total acid content of 3.04±0.3 g / L.

[0019] Furthermore, this invention also tested the relevant physicochemical indicators of chayote. The final results for the chayote pulp enzyme were as follows: In the antioxidant index determination, the ABTS free radical scavenging rate reached 89.44±0.073%, the DPPH free radical scavenging rate reached 78.56±0.013%, the SOD enzyme activity was 56.71±0.58 U / mL, and the total phenol content was 18.56±0.45 mg / L. This indicates that the fermented chayote pulp enzyme contains high antioxidant activity, effectively inhibiting the production of lipid oxidation off-flavors and making the chayote pulp enzyme have a harmonious aroma. The protein content was 3.7±0.21 mg / mL, the vitamin C content was 106.24±0.94 nmol / g, and the total pectin content was 82.58±0.49 mg / mL. This indicates that the fermented chayote pulp enzyme has a more refreshing and smooth taste, rich flavor layers, and good nutritional value.

[0020] Furthermore, experiments revealed that the chayote fermented beverage prepared according to this invention can reduce the weight of obese mice and improve their blood lipid levels. Simultaneously, the inventors unexpectedly discovered during their exploratory experiments that fermenting a beverage by mixing chayote and purslane significantly enhances the weight-loss and lipid-lowering effects of the fermented beverage, indicating that the fermented beverage prepared according to this invention has the effects of weight loss and reducing the risk of hyperlipidemia.

[0021] In summary, compared with the prior art, the method for preparing chayote fermented beverage provided by the present invention has the following advantages: (1) The chayote fermented beverage prepared by the method of the present invention has a yellow-green color, a glossy appearance, uniform juice, no impurities, a fresh aroma of chayote, a harmonious aroma, a perfect balance of sweet and sour, a refreshing and smooth taste, and a pure flavor.

[0022] (2) The chayote fermented beverage prepared by the method of the present invention has the advantages of high SOD enzyme activity, strong DPPH and ABTS free radical scavenging ability, and high vitamin C content. It has significant antioxidant activity and is a relatively ideal functional chayote fermented beverage. This method is of great value for developing a series of new chayote products, enriching the variety of chayote products, and expanding the market application fields of chayote. Attached Figure Description

[0023] Figure 1 The graph shows the effect of fermentation time on the sensory evaluation of chayote pulp enzyme.

[0024] Figure 2 The graph shows the effect of fermentation temperature on the sensory evaluation of chayote pulp enzyme.

[0025] Figure 3 The graph shows the effect of inoculation amount on the sensory evaluation of chayote pulp enzyme.

[0026] Figure 4 The graph shows the effect of initial sugar content on the sensory evaluation of chayote pulp enzyme. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Experiment 1: An Exploratory Experiment on Chayote Pulp Enzyme 1. Experimental Method: 1.1 Chayote Fermentation Process: (1) Raw material selection: Select fresh chayote, free from mold and insect holes, wash the mud and impurities on the surface of the chayote skin, peel it after washing, and cut it into pieces; (2) Inactivation of enzymes: Blanch the cut chayote pieces in 100 ℃ water for 10~15 s to inactivate enzymes; (3) Pulping: Take out the chayote pieces and put them into a juicer to extract the juice. Pour the extracted chayote juice into a homogenizer for a second pulverization. (4) Filtration: Filter the chayote juice through two layers of gauze to remove the chayote residue; (5) Sterilization: Sterilize at 121 °C for 15 min; (6) Ingredient adjustment: Add white sugar to adjust the sugar content of the chayote juice to the required level; (7) Inoculation and fermentation: The inoculation amount of the two microorganisms is the same. First, yeast is inoculated. After it completes the preset fermentation cycle, Lactobacillus plantarum is then introduced to achieve the synergistic fermentation of the two strains until the predetermined time point is reached.

[0029] (8) Sterilization: After fermentation is complete, sterilize at 121 °C for 15 min.

[0030] 1.2 Single-factor experiment on chayote pulp enzyme: The optimal fermentation process parameters were determined based on the sensory evaluation of single-factor experiments, with fermentation time, fermentation temperature, inoculum size, and initial sugar content as the core elements of the fermentation process.

[0031] (1) Fermentation time optimization experiment: Under constant process parameters (yeast culture temperature 28 ℃, Lactobacillus plantarum culture temperature 37 ℃, inoculum ratio 3%, initial sugar content 6%), five fermentation times of 8 h, 12 h, 16 h, 20 h and 24 h were set.

[0032] (2) Fermentation temperature verification experiment: Maintain the basic process parameters of 3% inoculum, 12 h fermentation time and 6% initial sugar content, and set the combination gradient of yeast culture temperature 27 ℃ / 30 ℃ / 33 ℃ and Lactobacillus plantarum culture temperature 35 ℃ / 37 ℃ / 39 ℃ respectively.

[0033] (3) Inoculation amount optimization experiment: Under the constant conditions of fermentation time of 12 h, yeast culture temperature of 28 ℃, Lactobacillus plantarum culture temperature of 37 ℃ and initial sugar concentration of 6%, five gradient inoculation amounts of 1%, 3%, 5%, 7% and 9% were set.

[0034] (4) Experiment on the effect of initial sugar content: The basic formula with a fermentation cycle of 12 h, yeast culture temperature of 28 ℃, Lactobacillus plantarum culture temperature of 37 ℃ and inoculum amount of 3% was used to prepare fermentation substrates with six sugar content gradients of 6%, 8%, 10%, 12%, 14% and 16%.

[0035] 1.3 Orthogonal Experiment on Chayote Pulp Enzyme: Based on the results of previous single-factor experiments, this study designed L9(3) 4 An orthogonal experimental design was used to optimize four key process parameters: fermentation time, fermentation temperature of the compound strain, inoculum size, and initial sugar content. Sensory evaluation scores were used as the core assessment value. A three-level, four-factor orthogonal experiment was conducted to systematically investigate the effects of interactions between various factors on the quality of chayote pulp enzyme, and to determine the optimal fermentation process parameters for chayote pulp enzyme. See Table 1 for details.

[0036] Table 1. Factor Levels in the Orthogonal Experiment for Chayote Pulp Enzyme 1.4 Detection of functional nutritional components of chayote pulp enzyme: 1.4.1 Determination of reducing sugars: The detection was performed according to the kit instructions. Standard glucose solutions with concentrations of 0.05, 0.10, 0.15, 0.20, and 0.25 mg / mL were prepared according to the instructions. Using distilled water as a reference, the absorbance was measured at 540 nm to obtain absorbance A. 标准 Simultaneously, blank tubes were prepared, and the absorbance was measured as Ablank. The concentration of the standard glucose solution was used as the ordinate, and the absorbance value ΔA (ΔA = Ablank) was plotted on the ordinate. 标准 -A 空白Using y as the abscissa, a linear regression model was constructed and a standard curve equation was plotted. The standard curve was y = 0.3147x + 0.0071, with R² = 0.9991. After centrifuging the sample at 3500 rpm for 10 minutes, the supernatant was carefully transferred to clean centrifuge tubes. Detection tubes and control tubes containing the sample were prepared simultaneously. The absorbance of the system was measured at 540 nm using a dual-beam UV-Vis spectrophotometer. The absorbance was calculated using the formula ΔA. 样品 =A 检测 -A 对照 Calculate the absorbance value of the sample to obtain the reducing sugar concentration of the sample.

[0037] 1.4.2 Determination of total sugar: The testing procedure was strictly followed according to the kit's instruction manual. Using a precision pipette and volumetric flask method, standard working solutions with concentration gradients of 0.1, 0.2, 0.5, 0.8, and 1.0 mg / mL were prepared using glucose standard as the primary reference. Using distilled water as a reference, absorbance was measured at 540 nm to obtain absorbance A. 标准 Simultaneously, blank tubes were prepared, and the absorbance was measured to be A. 空白 The standard glucose solution concentration is used as the ordinate, and the absorbance value ΔA (ΔA = A) is used as the plot. 标准 -A 空白 Using y as the abscissa, a linear regression model was constructed and a standard curve equation was plotted. The standard curve was y = 1.7005x + 0.0191, with R² = 0.9991. After centrifuging the sample at 3500 rpm for 10 minutes, the supernatant was carefully transferred to a clean centrifuge tube and measured according to the instructions to obtain ΔA. 样品 (ΔA) 样品 =A 样品 -A 空白 The total sugar content of the sample was calculated according to the instructions.

[0038] 1.4.3 Determination of total acidity: According to the national standard GB12345-2021 "Determination of Total Acidity in Food", the indicator titration method was used for detection. 20 mL of the fermentation sample was placed in a sterile centrifuge tube and centrifuged at 3500 rpm for 10 minutes. After centrifugation, 5 mL of the supernatant was transferred to a 50 mL volumetric flask and diluted to the mark with deionized water to prepare a 10-fold dilution working solution. 10 mL of the dilution was transferred to a 250 mL Erlenmeyer flask, and 1-2 drops of freshly prepared phenolphthalein indicator (1 g phenolphthalein dissolved in 60 mL of 95% ethanol, diluted to 100 mL with water) were added. Titration was performed with 0.01 mol / L or 0.1 mol / L sodium hydroxide standard titration solution until a faint red color persisted for 30 seconds. The volume of sodium hydroxide standard titration solution consumed was recorded. The determination was performed three times, and a blank experiment was also conducted. The calculation formula is as follows: In the formula: X is the total acid content, g / L; c represents the concentration of the sodium hydroxide standard titration solution, mol / L; V1 represents the volume of sodium hydroxide standard titration solution consumed when titrating the test solution, and V2 represents the volume of sodium hydroxide standard titration solution consumed when titrating the blank, mL; k represents the acid conversion factor, with lactic acid as the standard conversion factor, 0.090; F represents the dilution factor of the sample solution; V represents the sample volume used for determination, mL.

[0039] 1.4.4 Determination of total phenols: The method for determining tea polyphenols is based on the standard GB / T 31740.2. Weigh 0.5 g of chemically pure gallic acid standard and transfer it to a clean brown volumetric flask. Dilute to 100 mL with deionized water, ensuring the solution homogeneity meets the requirements of GB / T601-2016 "Preparation of Standard Titration Solutions for Chemical Reagents". Measure 1, 3, 5, 7, and 9 mL of the standard solution into 100 mL volumetric flasks and dilute to the mark with distilled water to prepare a series of gallic acid standard solutions with concentrations of 50, 150, 250, 350, and 450 mg / L. Use a double-beam UV-Vis spectrophotometer to measure the absorbance of each concentration of standard solution at the characteristic absorption wavelength of 765 nm. Plot the gallic acid equivalent concentration on the x-axis and correct the absorbance values ​​(A). 标准 -A 空白 Using the ordinate (Y-axis), establish the standard curve equation. Place the fermentation sample broth in a sterile centrifuge tube and centrifuge at 3500 rpm for 10 minutes. Carefully measure 0.1 mL of the supernatant into a 10 mL volumetric flask, add 0.5 mL of Folin-Ciocalteu solution, mix well, and allow to react at room temperature. Add sodium carbonate solution within 8 minutes, bringing the volume to 10 mL. Incubate in the dark at room temperature for 1 hour, and then measure the absorbance at [insert value here].

[0040] 1.4.5 Protein assay: Perform the test according to the kit instructions. Using reagent 1 as a reference, measure the absorbance at 540 nm to obtain absorbance A. 标准 Meanwhile, using distilled water as a reference, a blank tube was prepared, and the absorbance was measured to be A. 空白 The sample was centrifuged at 3500 rpm for 10 minutes using a high-speed centrifuge. After centrifugation, the supernatant was transferred to a sterile centrifuge tube, and the absorbance A of the sample was obtained according to the kit's operating procedures. 测定 Calculate the protein concentration of the sample according to the instructions.

[0041] 1.4.6 SOD enzyme activity assay: Strictly follow the testing procedure outlined in the kit's instruction manual. Preheat the spectrophotometer for at least 30 minutes, adjust the wavelength to 560 nm, and zero the instrument with distilled water. Simultaneously equilibrate the temperature of reagents one, two, and four. Add an appropriate amount of sample, following the order and dosage specified in the instructions. After thorough mixing, incubate at 37 ℃ for 30 minutes. Then, transfer the sample to a 1 mL glass cuvette and measure the absorbance at 560 nm to obtain A. 样品 A 样品对照 A 空白 and A 空白对照 Calculations yielded , By controlling the sample inhibition rate within the 30%–70% linear response range, which conforms to the linear fitting requirements of the Michaelis-Menten equation double reciprocal plotting method, the dose-response relationship of the enzyme activity assay results can be ensured to conform to the Beer-Lambert law. The 50% inhibition rate (IC50) corresponds to the optimal detection signal-to-noise ratio (S / N ≥ 10:1), at which point the weighted sum of random and systematic errors is minimized.

[0042] 1.4.7 Ascorbic acid (AsA) determination: AsA, also known as Vitamin C, should be detected according to the kit instructions. Using the standard solution as a reference, record the absorbance values ​​(A) of each concentration of the standard solution at the specified wavelength. 标准 The absorbance A of the sample was measured according to the instructions. 测定 The vitamin C concentration of the sample was calculated according to the instructions.

[0043] 1.4.8 ABTS Measurement: Prepare an ABTS solution of concentration [concentration value missing] with methanol, mix it thoroughly with an equal volume of potassium persulfate solution, and store it in the dark until ready for use. Dilute the above working solution with methanol to achieve an absorbance of [absorbance value missing] at a wavelength of 734 nm. Take 0.5 mL of the sample, add it to the working solution, and react at room temperature in the dark for 10 min. Measure the absorbance at [absorbance value missing].

[0044] In the formula: A1 represents the absorbance of 0.5 mL sample + 4 mL ABTS; A2 represents the absorbance of 0.5 mL sample + 4 mL methanol; A0 represents the absorbance of 0.5 mL methanol + 4 mL ABTS.

[0045] 1.4.9 DPPH Measurement: Prepare a 0.2 mmol / L DPPH solution with anhydrous ethanol. Take 0.5 mL of the sample, add the working solution, and react the sample at room temperature in the dark for 30 min. Measure the absorbance at a wavelength of 517 nm.

[0046] In the formula: A1 represents the absorbance of 1 mL sample + 2 mL DPPH-ethanol solution; A2 represents the absorbance of 1 mL sample + 2 mL ethanol; A0 represents the absorbance of 1 mL ethanol + 2 mL DPPH-ethanol solution.

[0047] 1.4.10. Determination of total pectin: Strictly follow the testing procedure as described in the kit's instruction manual. Prepare standard solutions with concentrations of 1.5, 1, 0.5, 0.25, 0.125, and 0.0625 μmol / mL as required by the instructions. Using distilled water as a reference, measure the absorbance under the specified conditions to obtain absorbance A. 标准 Simultaneously, blank tubes were prepared, and the absorbance was measured to be A. 空白 A standard curve was plotted with the concentration of the standard solution as the x-axis and the absorbance as the y-axis. The standard curve is shown in Figure R. 2 =0.9994. Prepare sample tubes and control tubes according to the instructions, obtain the absorbance of the samples, and calculate the total pectin concentration of the samples according to the instructions.

[0048] 1.4.11 Color difference measurement: The color of chayote pulp enzyme was determined using a colorimeter, with three measurements taken for the same sample and the average value taken. Using unfermented chayote juice as a standard, the color difference (ΔE) between the chayote pulp enzyme and the unfermented chayote juice was calculated using the following formula: In the formula: L is the brightness value of chayote pulp enzyme; L0 is the brightness value of chayote juice; α is the greenness value of chayote pulp enzyme; α0 is the greenness value of chayote juice; b is the yellowness value of chayote pulp enzyme; b0 is the yellowness value of chayote juice.

[0049] 1.4.12 Sensory evaluation: Nine volunteers, after training, formed an evaluation panel to conduct sensory evaluations of the chayote pulp enzyme, assessing its color, texture, aroma, and taste using a comprehensive evaluation method. The sensory evaluation criteria for the chayote pulp enzyme are shown in Table 2. The average score was calculated based on each evaluator's evaluation.

[0050] Table 2 Sensory Evaluation Table for Chayote Pulp Enzyme 2. Experimental Results: 2.1 Results and Analysis of Single-Factor Experiments: 2.1.1 Effect of fermentation time on sensory evaluation of chayote pulp enzyme: The effect of fermentation time on the sensory evaluation of chayote pulp enzyme is as follows: Figure 1 As shown. Figure 1 The following figures illustrate the effects of fermentation time on the sensory evaluation of chayote pulp enzymes. (a) The effect of fermentation time on SOD enzyme activity and sensory score; (b) The effect of fermentation time on protein and sensory score; (c) The effect of fermentation time on vitamin C and sensory score; (d) The effect of fermentation time on sugar content and sensory score; (e) The effect of fermentation time on total phenols and sensory score; (f) The effect of fermentation time on total acid and sensory score; and (g) The effect of fermentation time on antioxidant capacity and sensory score. The same letter indicates no significant difference (P>0.05), and different letters indicate significant differences (P<0.05).

[0051] Depend on Figure 1 It can be known that: The dynamic changes in various physicochemical indicators of chayote pulp enzymes over fermentation time reflect the rapid succession of microbial metabolic activities and the phased characteristics of substrate competition. At fermentation times of 8 h and 12 h, *Lactobacillus plantarum* and yeast proliferate rapidly, consuming large amounts of reducing sugars and total sugars as carbon sources through glycolysis, resulting in an overall decreasing trend in their content. Simultaneously, pectinase and cellulase secreted by microorganisms disrupt the chayote cell structure, releasing bound phenolic substances, causing the total phenol content to peak at 12 h. At the same time, vitamin C (AsA) content decreases slowly due to oxidation and microbial metabolic consumption, while SOD enzyme activity generally increases at 12 h as yeast activates its antioxidant defense system to resist the initial fermentation environmental stress. The total acid content, affecting the product's sour taste, accumulates rapidly with the acid-producing metabolism dominated by *Lactobacillus plantarum*, driving a decrease in the environmental pH. At 16 hours of fermentation, the chayote pulp enzyme is in an acidic environment, which inhibits the activity of some neutral proteases. Total phenols begin to decrease slowly due to oxidative polymerization or microbial degradation, while protein content shows a steady upward trend due to the continuous decomposition of plant proteins by extracellular proteases and the release of microbial proteins through autolysis. At this point, the further consumption of reducing sugars slows down the rate of total acid production. Additionally, the participation of some organic acids in secondary metabolism causes a temporary decline in total acid content at 16 hours of fermentation, resulting in a milder sour taste that harmonizes with the aroma of chayote. SOD enzyme activity, inhibited by the acidic environment and the shift in microbial metabolic focus to carbon source utilization, reaches its lowest point at 20 hours of fermentation. However, antioxidant activity peaks at 16 hours due to the synergistic effect of total phenols and SOD enzyme, at which point free radical scavenging ability is strongest. At 24 hours of fermentation, *Lactobacillus plantarum* adapts to the environment and recovers its activity, reactivating the SOD synthesis mechanism and causing a second increase in its content. Total acid increases again due to continuous acid production by *Lactobacillus plantarum* and the generation of Maillard reaction intermediates. At this point, the continuous accumulation of protein can effectively enhance the nutrient absorption rate of enzymes, while the linear decline of vitamin C highlights its disadvantages in heat sensitivity and metabolic priority. Further fermentation exacerbates the loss of vitamin C, and the release of ammonia due to the death of bacteria leads to the deterioration of the flavor of chayote pulp enzyme.

[0052] Based on the above analysis, 16 hours was selected as the optimal fermentation time. When fermented for 16 hours, the chayote pulp enzyme exhibited moderate total acid and sugar content, a perfect balance of sweet and sour, a refreshing and smooth taste, rich fruity aroma and refreshing flavor, and a bright color, achieving the highest sensory score. Under these conditions, the SOD enzyme activity was 8.98 U / mL, protein content was 5.61 mg / mL, vitamin C content was 158.47 mg / mL, total sugar content was 58.76 mg / mL, reducing sugar content was 20.97 mg / mL, total phenol content was 11.21 mg / L, total acid content was 3.32 g / L, DPPH free radical scavenging rate was 49.9%, ABTS free radical scavenging rate was 76.29%, and the sensory score was 70.67.

[0053] 2.1.2 Effect of fermentation temperature on sensory evaluation of chayote pulp enzyme: The effect of fermentation temperature on the sensory evaluation of chayote pulp enzyme is as follows: Figure 2 As shown. Figure 2 The following figures illustrate the effects of fermentation temperature on the sensory evaluation of chayote pulp enzymes. (a) The effect of fermentation temperature on SOD enzyme activity and sensory score; (b) The effect of fermentation temperature on protein and sensory score; (c) The effect of fermentation temperature on vitamin C and sensory score; (d) The effect of fermentation temperature on sugar content and sensory score; (e) The effect of fermentation temperature on total phenols and sensory score; (f) The effect of fermentation temperature on total acid and sensory score; and (g) The effect of fermentation temperature on antioxidant capacity and sensory score. The same letter indicates no significant difference (P>0.05), and different letters indicate significant differences (P<0.05).

[0054] Depend on Figure 2 It can be known that: The influence of the fermentation temperature combination of *Saccharomyces cerevisiae* and *Lactobacillus plantarum* on the physicochemical indicators and sensory evaluation during the fermentation of chayote pulp enzymes reflects the dynamic balance between the metabolic characteristics of the strains and their temperature sensitivity. When *Saccharomyces cerevisiae* was fermented at 30℃ and *Lactobacillus plantarum* at 37℃, the sensory score of the chayote pulp enzymes reached its peak. At 30℃, *Saccharomyces cerevisiae* exhibited highly efficient sugar metabolism, preferentially breaking down polysaccharides in chayote into monosaccharides, leading to a temporary increase in total sugar content, while simultaneously generating ethanol and esters, imparting a fresh chayote aroma to the fermented chayote pulp. During this stage, SOD enzyme activity increased due to the enhanced antioxidant stress response of the yeast; while protein content decreased due to the breakdown of chayote plant protein into small peptides by proteases secreted by *Saccharomyces cerevisiae*. Although vitamin C showed a decreasing trend due to oxidation and microbial consumption, it retained some acid-regulating function. When the temperature switched to 37℃, the metabolic activity of *Lactobacillus plantarum* significantly increased, but the total acid content decreased due to the volatilization of organic acids promoted by high temperature or the participation of acids in Maillard reactions to generate caramel-like flavor compounds. Meanwhile, the thermostable protease secreted by *Lactobacillus plantarum* further breaks down the remaining proteins into amino acids, while the release of intracellular proteins from bacterial autolysis causes the protein content to rebound. The upward trend in total phenol content during this stage is attributed to the high temperature promoting the degradation of cell wall polysaccharides, releasing more bound phenolic substances. Furthermore, the SOD enzyme activity reaches its peak at this time due to the synergistic effect of total phenols and small molecule peptides, effectively inhibiting the production of lipid oxidation odors.

[0055] Based on the above analysis, the optimal fermentation temperature for *Saccharomyces cerevisiae* was determined to be 30 ℃, and for *Lactobacillus plantarum*, it was 37 ℃. This temperature combination represents the optimal fermentation temperature process parameters for chayote pulp enzyme. Under this temperature combination, the chayote pulp enzyme exhibits a moderate accumulation of reducing sugars, balancing sweetness and sourness, and its antioxidant activity is at its peak, effectively inhibiting the production of lipid oxidation off-flavors. Under these conditions, the SOD enzyme activity was 10.99 U / mL, protein content was 3.08 mg / mL, vitamin C content was 126.15 mg / mL, total sugar content was 70.72 mg / mL, reducing sugar content was 21.37 mg / mL, total phenol content was 10.87 mg / L, total acid content was 7.68 g / L, DPPH free radical scavenging rate was 61.06%, ABTS free radical scavenging rate was 84.58%, and the sensory score was 72.22 points.

[0056] 2.1.3 Effect of inoculum size on sensory evaluation of chayote pulp enzyme: The effect of inoculum size on the sensory evaluation of chayote pulp enzyme is as follows: Figure 3 As shown. Figure 3The following figures illustrate the effect of inoculum size on the sensory evaluation of chayote pulp enzymes. (a) The effect of inoculum size on SOD enzyme activity and sensory score; (b) The effect of inoculum size on protein and sensory score; (c) The effect of inoculum size on vitamin C and sensory score; (d) The effect of inoculum size on sugar content and sensory score; (e) The effect of inoculum size on total phenols and sensory score; (f) The effect of inoculum size on total acid and sensory score; and (g) The effect of inoculum size on antioxidant activity and sensory score. The same letter indicates no significant difference (P>0.05), and different letters indicate significant differences (P<0.05).

[0057] Depend on Figure 3 It can be known that: During the fermentation of chayote pulp enzymes, the effect of inoculum size on sensory evaluation was reflected through the dynamic balance between microbial metabolic intensity and substrate competition. The highest sensory scores were achieved when both *Saccharomyces cerevisiae* and *Lactobacillus plantarum* had an inoculum size of 5%. Under the condition that both *Saccharomyces cerevisiae* and *Lactobacillus plantarum* had an inoculum size of 5%, metabolic efficiency and product coordination were balanced: initially, the microbial community proliferated moderately, with *Saccharomyces cerevisiae* preferentially breaking down sugars to produce ethanol and esters; simultaneously, the acid production rate of *Lactobacillus plantarum* matched sugar consumption, resulting in a gradual increase in total acid content and avoiding excessive acidification that could stimulate the taste. At this stage, SOD enzyme activity reached its peak due to the microbial community's antioxidant stress response, scavenging free radicals while inhibiting the production of lipid oxidation off-flavors. The increasing protein content stemmed from the balance between protease activity and substrate supply at a moderate inoculum size, which effectively decomposed plant proteins to improve texture while avoiding excessive accumulation of bitter peptides. An inoculum of 5% Saccharomyces cerevisiae and Lactobacillus plantarum achieved the optimal balance between functional activity, flavor balance and texture improvement by optimizing the microbial metabolic rhythm. Under these conditions, the synergistic peak of total acid, total phenol and SOD enzyme activity supported antioxidant and flavor stability, while the moderate conversion of sugars and proteins avoided resource depletion and by-product accumulation.

[0058] Based on the above analysis, an inoculum size of 5% for both *Saccharomyces cerevisiae* and *Lactobacillus plantarum* is the optimal inoculum size. Under these conditions, the SOD enzyme activity was 11.76 U / mL, protein content was 3.79 mg / mL, vitamin C content was 152.19 mg / mL, total sugar content was 27.97 mg / mL, reducing sugar content was 24.78 mg / mL, total phenol content was 7.72 mg / L, total acid content was 2.52 g / L, DPPH free radical scavenging rate was 55.56%, ABTS free radical scavenging rate was 72.53%, and sensory score was 70.56 points.

[0059] 2.1.4 Effect of initial sugar content on sensory evaluation of chayote pulp enzyme: The effect of initial sugar content on the sensory evaluation of chayote pulp enzyme is as follows: Figure 4 As shown. Figure 4 The following figures illustrate the effect of initial sugar content on the sensory evaluation of chayote pulp enzymes. (a) shows the effect of initial sugar content on SOD enzyme activity and sensory score; (b) shows the effect of initial sugar content on protein and sensory score; (c) shows the effect of initial sugar content on vitamin C and sensory score; (d) shows the effect of initial sugar content on sugar content and sensory score; (e) shows the effect of initial sugar content on total phenols and sensory score; (f) shows the effect of initial sugar content on total acid and sensory score; and (g) shows the effect of initial sugar content on antioxidant capacity and sensory score. The same letter indicates no significant difference (P>0.05), and different letters indicate significant differences (P<0.05).

[0060] Depend on Figure 4 It can be known that: During the fermentation of chayote pulp enzymes, differences in initial sugar content affect microbial metabolic pathways and product composition, thus determining sensory quality. At an initial sugar content of 6%, the carbon source supply and microbial needs are well-matched, resulting in a more balanced synergistic metabolism between *Saccharomyces cerevisiae* and *Lactobacillus*. This avoids product deficiency in the low-sugar group while mitigating metabolic inhibition in the high-sugar group. Furthermore, the synergistic accumulation of total acid and total phenols, the increasing trend of antioxidant activity, and the dynamic conversion of proteins and sugars balance smoothness and bitterness threshold; the phased retention of vitamin C enhances flavor complexity through acidity regulation. The optimal initial sugar content was set at 6%. Under this condition, the sensory evaluation score was the highest, the SOD enzyme activity was 15.28 U / mL, the protein content was 2.03 mg / mL, the vitamin C content was 71.83 mg / mL, the total sugar content was 29.81 mg / mL, the reducing sugar content was 26.14 mg / mL, the total phenol content was 13.22 mg / L, the total acid content was 1.9 g / L, the DPPH free radical scavenging rate was 61.32%, the ABTS free radical scavenging rate was 77.62%, and the sensory score was 76.63 points.

[0061] 2.2 Analysis of Orthogonal Experiment Results: 2.2.1 Analysis of the results of orthogonal optimization of chayote pulp enzyme production process: Based on the sensory scores from single-factor experiments, orthogonal experiments were conducted to analyze the effects of fermentation time (A), fermentation temperature (B), inoculum size (C), and initial sugar content (D) on sensory scores. The results of the orthogonal experiments are shown in Table 3. Table 3 shows that the order of influence of each factor on the sensory scores of chayote pulp enzyme is as follows: [Table data would be inserted here]. Analysis of the orthogonal experimental results indicates that the optimal combination for chayote pulp enzyme fermentation is A1B3C3D3. Fermentation time is the most significant influencing factor on the sensory evaluation of chayote pulp enzyme. Fermentation time determines the fermentation duration of yeast and Lactobacillus plantarum, thus affecting the total acid and sugar content in the final product and its flavor. Inoculum size is a secondary factor, affecting the metabolic rhythm of the microbial community in the final chayote product. Fermentation temperature and initial sugar content have no significant impact on the sensory scores of chayote pulp enzyme. The optimal fermentation conditions for chayote pulp enzyme are as follows: adjust the initial sugar content to 7%, add 6% inoculum of Saccharomyces cerevisiae and ferment for 14 h, then add 6% inoculum of Lactobacillus plantarum and continue fermentation for 14 h. The fermentation temperature of the first stage of Saccharomyces cerevisiae is 31 ℃, and the fermentation temperature of the second stage of Lactobacillus plantarum and Saccharomyces cerevisiae is 38 ℃.

[0062] Table 3. Orthogonal optimization experiment and results analysis of chayote pulp enzyme. 2.2.2 Analysis of Optimal Process Validation Results: The optimal fermentation process for chayote was verified. The fermentation process involved adjusting the initial sugar content to 7%, adding 6% inoculum of Saccharomyces cerevisiae for 14 hours of fermentation, followed by adding 6% inoculum of Lactobacillus plantarum for another 14 hours of fermentation. Under the conditions that the fermentation temperature of the first stage of Saccharomyces cerevisiae was 31 ℃ and the fermentation temperature of the second stage of Lactobacillus plantarum and Saccharomyces cerevisiae was 38 ℃, the A1B3C3D3 combination product obtained the highest sensory score of 84.6 points. The chayote pulp enzyme obtained under these fermentation conditions was yellow-green in color, glossy, with uniform juice, no impurities, and had the fragrance of chayote. The aroma was harmonious, the sweet and sour taste was just right, the taste was refreshing and smooth, and it had the flavor of chayote with a pure taste.

[0063] 2.3 Analysis of Physicochemical Indicators of Chayote Pulp Enzyme: 2.3.1 Analysis of SOD enzyme activity and antioxidant properties: (1) SOD enzyme activity analysis: Superoxide dismutase (SOD) is ubiquitous in organisms and serves as the body's first line of defense against excessive hydroxyl radicals and reactive oxygen species such as hydrogen peroxide. SOD activity is also closely related to its scavenging rate against DPPH and ABTS radicals. Table 4 shows that the SOD activity after fermentation was 56.71 ± 0.58 U / mL, significantly higher than before fermentation. This is because the fermentation process utilizes multiple mechanisms—microbial biosynthesis and secretion, release and activation of endogenous enzymes, substrate transformation to provide precursors, and optimization of the enzymatic reaction environment—to synergistically enhance the SOD activity in chayote pulp enzymes. This indicates that fermentation effectively improves the antioxidant activity of the product.

[0064] (2) Radical scavenging capabilities of DPPH and ABTS: Each individual factor during fermentation affects the final antioxidant activity of the product. The scavenging effect on ABTS and DPPH free radicals is a commonly used indicator for evaluating in vitro antioxidant capacity. Table 4 shows that after fermentation, the ABTS free radical scavenging rate reached 89.44±0.073%, and the DPPH free radical scavenging rate reached 78.56±0.013%, significantly higher than before fermentation. This indicates that chayote cells undergo a stress response during fermentation and enzymatic hydrolysis, releasing endogenous antioxidant components as cofactors to enhance their free radical scavenging ability. This pattern aligns with the findings proposed by scholar Wei Jianmin in his research on the antioxidant activity of enzymes.

[0065] Table 4. Results of SOD enzyme activity and antioxidant activity analysis of chayote pulp before and after fermentation. 2.3.2 Analysis of total phenol content and total acidity: (1) Total phenol content analysis: Polyphenols are widely found in plant-based foods and possess strong antioxidant properties; related studies show they are abundant in enzymes. The increase in total phenol content before and after fermentation is related to the high temperature promoting cell wall destruction and inhibiting phenol oxidase activity during fermentation. As shown in Table 5, the total phenol content of the fermented product reached 18.56±0.45 mg / L, a significant increase compared to before fermentation, effectively inhibiting the production of lipid oxidation off-flavors.

[0066] (2) Total acid content analysis: Total acidity is one of the main quality indicators of enzyme products. During fermentation, the total acid content is related to the volatilization of organic acids due to high temperature or the participation of acids in Maillard reactions to generate caramel-like flavor substances. As shown in Table 5, the total acid content of the product after fermentation reached 3.04±0.3 g / L, which effectively balanced the sweetness and sourness of the chayote pulp enzyme.

[0067] Table 5. Analysis results of total phenols and total acids in chayote pulp before and after fermentation. 2.3.3 Analysis of protein and vitamin C content: (1) Protein content analysis: During fermentation, protein degradation enhances enzyme absorbability, and the resulting peptides further improve functional activity, texture, and smoothness. Table 6 shows that the protein content of the fermented product reached 3.7 ± 0.21 mg / mL, a decrease compared to before fermentation. This is because yeast secretes proteases that break down chayote plant protein into small peptides. The decrease in protein content improves the smoothness of the chayote pulp enzyme.

[0068] (2) Vitamin C content analysis: Vitamin C is a water-soluble vitamin that is sensitive to heat, light, and oxygen, and is easily oxidized and decomposed. During the fermentation of chayote pulp enzyme, the dynamic changes in vitamin C content reflect the complex interactions between microbial metabolism, oxidation reactions, and environmental conditions. Table 6 shows that the vitamin C content reached 106.24 ± 0.94 nmol / g after fermentation, effectively regulating the acidity of the fermented chayote pulp enzyme and enhancing its flavor profile. This change indicates that during fermentation, microorganisms directly synthesize or indirectly protect vitamin C through metabolic activities. Simultaneously, enzymatic hydrolysis and cell rupture promote the conversion of bound substances into free substances, while the acidic environment and the synergistic effect of antioxidants reduce its degradation, ultimately leading to a significant increase in vitamin C content after fermentation.

[0069] Table 6. Analysis results of enzyme protein and vitamin C in chayote pulp before and after fermentation. 2.3.4 Analysis of total pectin and sugar content: (1) Analysis of total pectin content: Pectin is a natural high-molecular-weight polysaccharide found in the primary cell walls and middle lamella of plants. During fermentation, it not only serves as a nutrient source but also enhances yeast metabolism and influences the final product's taste and flavor by improving the fermentation environment. Table 7 shows that the total pectin content after fermentation reached 82.58 ± 0.49 mg / mL, improving the enzyme's nutritional value and market competitiveness. The key reason for the significant increase in total pectin content after fermentation is that insoluble protopectin is converted into soluble pectin through enzymatic hydrolysis and released into the solution through cell structure disruption. Simultaneously, the acidic environment stabilizes the pectin's solubility.

[0070] (2) Sugar content analysis: Reducing sugars and total sugars play crucial roles in enzyme fermentation, and their interaction directly affects fermentation efficiency and the quality of the final product. Reducing sugars, with their rapid fermentation characteristics, directly influence the fermentation rate and product formation, while total sugars provide a wide range of energy sources required by microorganisms. Table 7 shows that after fermentation, the reducing sugar content reached 27.63±1.33 mg / mL, and the total sugar content reached 48.23±1.24 mg / mL. Compared to before fermentation, the decrease in reducing sugars and total sugars reduced the cloying sweetness and gave the fermented chayote pulp enzyme a fruity aroma and refreshing taste. The increase in reducing sugars and total sugars after fermentation is due to the conversion of polysaccharides into monosaccharides or oligosaccharides under enzymatic hydrolysis, the release of stored sugars through cell structure destruction, and the metabolic preferences of microorganisms and the acidic environment providing conditions for sugar accumulation.

[0071] Table 7. Analysis results of total pectin and sugar content in chayote pulp enzymes before and after fermentation. 2.3.5 Color Difference Analysis: In color difference detection, △L represents the change in brightness, with positive values ​​indicating a whiter color and negative values ​​indicating a darker color. △a represents the change in red and green, with positive values ​​indicating a redder color and negative values ​​indicating a greener color. △b represents the change in yellow and blue, with positive values ​​indicating a yellower color and negative values ​​indicating a bluer color. △E represents the total color difference, used to measure the degree of difference between two colors. The larger the △E value, the greater the color difference. Unfermented chayote pulp was used as the standard sample, and the results were compared with fermented chayote pulp enzyme. The results are shown in Table 8.

[0072] After fermentation, △a is positive, indicating a greenish tint, but the difference is small and cannot be distinguished by the naked eye. △b is positive, indicating a yellowish tint; △E is large, indicating a significant color difference between fermented chayote pulp enzyme and unfermented chayote pulp; △L is positive, indicating that fermented chayote pulp enzyme is whitish. The main pigment in chayote pulp is β-carotene, which maintains strong stability in the pH range of 3 to 7

[23] . After fermentation, the color of chayote pulp enzyme changes from bluish-green to an attractive pale yellowish-green, with a glossy appearance, no browning, uniform texture, and no impurities or sediment. It differs from the color of unfermented chayote pulp, but is more attractive overall.

[0073] Table 8. Color difference analysis of chayote pulp enzymes before and after fermentation. 3. Experimental conclusions: 3.1 Based on sensory evaluation, the optimal fermentation process for chayote juice was determined by exploring the fermentation time, temperature, inoculum size of *Saccharomyces cerevisiae* and *Lactobacillus plantarum*, and initial sugar content. The order of influence of various factors on the sensory score of chayote pulp enzyme was: fermentation time > inoculum size > initial sugar content > fermentation temperature. The optimal fermentation conditions were: adjusting the initial sugar content to 7%, adding 6% inoculum of Saccharomyces cerevisiae for 14 h of fermentation, followed by adding 6% inoculum of Lactobacillus plantarum for another 14 h of fermentation. The fermentation temperature for the first stage of Saccharomyces cerevisiae was 31 ℃, and the fermentation temperature for the second stage of Lactobacillus plantarum and Saccharomyces cerevisiae was 38 ℃. Under the optimal fermentation conditions, the chayote pulp enzyme achieved the highest sensory score of 84.6 points, with a total sugar content of 48.23±1.24 mg / mL, a reducing sugar content of 27.63±1.33 mg / mL, and a total acid content of 3.04±0.3 g / L. This indicates that under these conditions, the chayote pulp enzyme had a perfect balance of sweet and sour, possessing the fruity aroma and refreshing taste of chayote.

[0074] 3.2. The relevant physicochemical indicators of chayote were tested, and the final results for chayote pulp enzyme were as follows: The antioxidant properties of the fermented chayote pulp enzyme were as follows: ABTS free radical scavenging rate reached 89.44±0.073%, DPPH free radical scavenging rate reached 78.56±0.013%, SOD enzyme activity was 56.71±0.58 U / mL, and total phenol content was 18.56±0.45 mg / L. These results indicate that the fermented chayote pulp enzyme possesses high antioxidant activity, effectively inhibiting the production of lipid oxidation off-flavors and resulting in a more harmonious aroma. The protein content was 3.7±0.21 mg / mL, vitamin C content was 106.24±0.94 nmol / g, and total pectin content was 82.58±0.49 mg / mL. These findings suggest that the fermented chayote pulp enzyme has a smoother, more refreshing taste, rich flavor profile, and good nutritional value. Using unfermented chayote juice as a standard, the color differences of the chayote pulp enzyme were measured as follows: ΔL = 2.54 ± 34, Δa = 1.15 ± 0.86, Δb = 4.58 ± 0.57, and ΔE = 19.15 ± 0.92. Analysis of these color difference parameters showed that the Δa, Δb, and ΔL values ​​of the fermented chayote pulp enzyme were all positive, indicating that fermentation caused the chayote pulp enzyme to shift towards a yellowish-green color, with increased brightness, becoming closer to a pale yellowish-green and glossy. The ΔE value significantly increased compared to before fermentation, which is due to the influence of microbial metabolites, resulting in a noticeable color difference between the fermented and unfermented chayote pulp enzyme.

[0075] Example 1: A method for preparing a fermented chayote beverage Step S1: Wash the chayote, peel it, cut it into chunks, and blanch the cut chayote chunks in 100℃ water for 10 seconds to inactivate the enzymes, thus obtaining chayote chunks. Step S2: Juice the chayote chunks obtained in step S1, filter with two layers of gauze, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize at 121 ℃ for 15 min to obtain chayote juice. Step S3: Add white sugar to the chayote juice obtained in step S2, wherein the amount of white sugar added is 6% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast solution, wherein the inoculation amount of brewer's yeast solution is 5% of the total volume of the chayote juice, and the viable count of the brewer's yeast solution is 10. 12 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 33 °C for 16 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at 5% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 9 The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 39 °C for 16 hours, centrifuged, and the supernatant was collected to obtain chayote pulp enzyme. The enzyme was then sterilized at 121 °C for 15 minutes and packaged.

[0076] Example 2: A method for preparing a fermented chayote beverage Step S1: Wash the chayote, peel it, cut it into chunks, and blanch the cut chayote chunks in 100 ℃ water for 12 seconds to inactivate the enzymes, thus obtaining chayote chunks. Step S2: Juice the chayote chunks obtained in step S1, filter with two layers of gauze, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize at 121 ℃ for 15 min to obtain chayote juice. Step S3: Add white sugar to the chayote juice obtained in step S2, wherein the amount of white sugar added is 7% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast solution, wherein the inoculation amount of brewer's yeast solution is 6% of the total volume of the chayote juice, and the viable count of the brewer's yeast solution is 1×10⁻⁶. 11 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 31 °C for 14 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at a concentration of 6% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 10 The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 38 °C for 16 hours, centrifuged, and the supernatant was collected to obtain chayote pulp enzyme. The enzyme was then sterilized at 121 °C for 15 minutes and packaged.

[0077] Example 3: A method for preparing a fermented chayote beverage Step S1: Wash the chayote, peel it, cut it into chunks, and blanch the cut chayote chunks in 100 ℃ water for 15 seconds to inactivate the enzymes, thus obtaining chayote chunks. Step S2: Juice the chayote chunks obtained in step S1, filter with two layers of gauze, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize at 121 ℃ for 15 min to obtain chayote juice. Step S3: Add white sugar to the chayote juice obtained in step S2, wherein the amount of white sugar added is 8% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast solution, wherein the inoculation amount of brewer's yeast solution is 7% of the total volume of the chayote juice, and the viable count of the brewer's yeast solution is 1×10⁻⁶. 10 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 27 °C for 12 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at 7% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 11 The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 35 °C for 12 hours, centrifuged, and the supernatant was collected to obtain chayote pulp enzyme. The enzyme was then sterilized at 121 °C for 15 minutes and packaged.

[0078] Example 4: A method for preparing a fermented chayote beverage Step S1: Wash the chayote, peel it, cut it into chunks, and blanch the cut chayote chunks in 100 ℃ water for 12 seconds to inactivate the enzymes, thus obtaining chayote chunks. Step S2: Juice the chayote chunks obtained in step S1, filter with two layers of gauze, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize at 121 ℃ for 15 min to obtain chayote juice. Step S3: Mix the chayote juice obtained in step S2 with the prickly ash juice, wherein the volume ratio of the chayote juice to the prickly ash juice is 1:0.3, to obtain a mixed liquid. Then add white sugar, wherein the amount of white sugar added is 7% m / v of the total mass of the mixed liquid. Inoculate with brewer's yeast solution, wherein the inoculation amount of brewer's yeast solution is 6% of the total volume of the chayote juice, and the viable count of the brewer's yeast solution is 1×10⁻⁶. 11 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 31 °C for 14 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at a concentration of 6% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 10 The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 38 °C for 16 hours, centrifuged, and the supernatant was collected to obtain chayote pulp enzyme. The enzyme was then sterilized at 121 °C for 15 minutes and packaged.

[0079] Example 4: A method for preparing a fermented chayote beverage Step S1: Wash the chayote, peel it, cut it into chunks, and blanch the cut chayote chunks in 100 ℃ water for 12 seconds to inactivate the enzymes, thus obtaining chayote chunks. Step S2: Juice the chayote chunks obtained in step S1, filter with two layers of gauze, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize at 121 ℃ for 15 min to obtain chayote juice. Step S3: Mix the chayote juice obtained in step S2 with the prickly ash juice. The prickly ash juice is obtained by juicing prickly ash, filtering, collecting the filtrate, and homogenizing the filtrate. The volume ratio of the chayote juice to the prickly ash juice is 1:0.4. Then, add white sugar at 7% m / v of the total mass of the mixture. Inoculate with brewer's yeast solution at 6% of the total volume of the chayote juice, with a viable count of 1×10⁻⁶. 11 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 31 °C for 14 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at a concentration of 6% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 10 The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 38 °C for 16 hours, centrifuged, and the supernatant was collected to obtain chayote pulp enzyme. The enzyme was then sterilized at 121 °C for 15 minutes and packaged.

[0080] Comparative Example 1: A method for preparing a fermented beverage made from *Lepidium apetalum* Step S1: Wash the prickly pear and blanch it in 100 ℃ water for 12 seconds to inactivate the enzymes, thus obtaining pretreated prickly pear. Step S2: Juice the pretreated prickly ash obtained in step S1, filter it with two layers of gauze, collect the filtrate, homogenize the filtrate, filter it, collect the filtrate, sterilize it at 121 ℃ for 15 min to obtain prickly ash juice. Step S3: Add white sugar to the chayote juice obtained in step S2. The amount of white sugar added is 7% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast solution. The inoculation amount of brewer's yeast solution is 6% of the total volume of the chayote juice. The viable count of the brewer's yeast solution is 1×10⁻⁶. 11 The mixture was inoculated with cfu / mL, oxygen was introduced, and fermentation was carried out at 31 °C for 14 h. After fermentation, *Lactobacillus plantarum* culture was inoculated at a concentration of 6% of the total volume of chayote juice, and the viable count of the *Lactobacillus plantarum* culture was 2.5 × 10⁻⁶. 10The concentration of cfu / mL was increased, and the mixture was sealed after purging with oxygen for 2 hours. It was then fermented at 38 °C for 16 hours, centrifuged, and the supernatant was collected to obtain the *Lepidium apetalum* procrease enzyme. This was then sterilized at 121 °C for 15 minutes and packaged to obtain the final product.

[0081] Experiment Example 1: The Weight Loss and Lipid-Lowering Effects of Chayote Fermented Beverage 1. Experimental materials: The chayote fermented beverages prepared in Examples 2 and 4, and the purslane fermented beverage prepared in Comparative Example 1.

[0082] 2. Experimental methods: Forty clean-grade male Kunming mice were selected and, after one week of acclimatization, randomly divided into two groups: a normal control group (n=8) fed a basal diet and the remaining mice fed a high-fat diet. Mouse weight was measured daily. After successful model establishment in week 4, unsuitable mice were removed based on weight, and 32 high-fat mice were selected and randomly divided into four groups of eight each: model group, Example 2 group, Comparative Example 1 group, and Example 4 group. The treatment groups were administered via gavage at a dose of 40 mg / kg / day. The normal control and model groups were given a certain amount of physiological saline. During the treatment period, the normal control group continued to be fed a basal diet, while the other groups were fed a high-fat diet. After 8 weeks of treatment, the weight of each group was measured, and the average weight was calculated. The mice were then fasted for 12 hours, and blood was collected by enucleation, centrifugation, and separation of the supernatant serum. LDL levels in the serum were measured according to the kit instructions. C, HDL C content.

[0083] 3. Experimental Results: The experimental results are shown in Table 9.

[0084] Table 9 Results of the weight loss and lipid-lowering effects of chayote fermented beverage Note: Compared to the model group * This indicates that P < 0.05. ** This indicates that P < 0.01.

[0085] As shown in Table 9, the chayote fermented beverage prepared by this invention has the effect of weight loss and lipid reduction. In particular, the fermented beverage prepared by mixing chayote and prickly ash can significantly enhance the weight loss and lipid reduction effect of the enzyme beverage through interaction between the two.

[0086] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a fermented chayote beverage, characterized in that, Includes the following steps: Step S1: Wash the chayote, peel it, cut it into chunks, and deactivate the enzymes to obtain chayote chunks; Step S2: Juice the chayote chunks obtained in step S1, filter, collect the filtrate, homogenize the filtrate, filter, collect the filtrate, sterilize, and obtain chayote juice. Step S3: Add white sugar to the chayote juice obtained in step S2. The amount of white sugar added is 6-8% m / v of the total mass of the chayote juice. Inoculate with brewer's yeast culture, introduce oxygen, and ferment at a temperature of 27-33 ℃ for 10-20 h. After fermentation, inoculate with Lactobacillus plantarum culture, introduce oxygen for 1-3 h, seal, and ferment at a temperature of 35-39 ℃ for 10-20 h. Centrifuge, take the supernatant to obtain chayote pulp enzyme, sterilize, and package to obtain the product.

2. The method for preparing chayote fermented beverage as described in claim 1, characterized in that, The enzyme inactivation treatment in step S1 is to blanch the food in boiling water for 10-15 seconds.

3. The method for preparing the chayote fermented beverage as described in claim 1, characterized in that, In step S3, the inoculation amount of the brewer's yeast solution is 3-7% of the total volume of the chayote juice.

4. The method for preparing chayote fermented beverage as described in claim 3, characterized in that, The viable count of the brewer's yeast culture is 1×10⁻⁶. 10 ~1×10 12 cfu / mL.

5. The method for preparing the chayote fermented beverage as described in claim 1, characterized in that, In step S3, the inoculation amount of Lactobacillus plantarum solution is 3-7% of the total volume of chayote juice.

6. The method for preparing chayote fermented beverage as described in claim 5, characterized in that, The Lactobacillus plantarum liquid The viable count was 2.5 × 10⁻⁶. 9 ~2.5×10 11 cfu / mL.

7. The method for preparing the chayote fermented beverage as described in claim 1, characterized in that, Step S3 also includes adding chayote juice to the chayote juice. The chayote juice is obtained by juicing chayote, filtering, taking the filtrate, and homogenizing the filtrate.

8. The method for preparing chayote fermented beverage as described in claim 7, characterized in that, In step S3, the volume ratio of chayote juice to purslane juice is 1:(0.2~0.6).

9. A chayote fermented beverage prepared by the method described in any one of claims 1 to 8.

10. The use of the chayote fermented beverage as described in claim 9 in the preparation of products for controlling weight or improving blood lipids.

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