Preparation method of rose and physalis alkekengi enzyme beverage

Abstract

The preparation method comprises the following steps: mixing soybean whey with rose residue powder, inoculating a mixed seed solution of lactobacillus plantarum SJ-L-1 and saccharomyces cerevisiae, and fermenting to prepare a physalis alkekengi stock solution. According to the invention, lactobacillus plantarum SJ-L-1 and saccharomyces cerevisiae are utilized, soybean whey is used as a fermentation substrate, and rose residue powder is used as an auxiliary agent to prepare the sour pulp beverage. The obtained physalis alkekengi beverage has bright rose red color, not only retains the color, fragrance and taste of roses, but also eliminates the peculiar smell of soybean whey, meanwhile, ester fragrance and mellow fragrance are generated in the fermentation process, the flavor is rich, the taste is sour and refreshing, in addition, glucoside type isoflavone is converted into aglycone type isoflavone to the greatest extent, and the nutritional value of the rose physalis alkekengi beverage is improved. The method is simple in technological process, easy and convenient to operate, low in cost and easy to industrialize.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and particularly relates to a method for preparing a rose physalis enzyme beverage. Background Art

[0002] Tofu is a traditional food in my country, made by coagulating fresh hot soy milk. Tofu is rich in nutrients, and eating it can bring us various health benefits. However, many nutrients in tofu, such as oligosaccharides, bioactive compounds, soy isoflavones, etc., are lost to soy whey during the production process. Soy whey is a by-product of tofu production and contains a high concentration of water-soluble soy nutrients. According to traditional processing technology, 1 kg of soybeans turns into tofu, producing about 8.95 liters of soy whey. Soy whey, also known as yellow pulp water, is often discharged as wastewater. Yellow pulp water contains relatively rich nutrients, with a biochemical oxygen demand of up to 5000-10000 mg / L and a chemical oxygen demand of 15000-24000 mg / L. After the yellow pulp water from the soy product processing plant is discharged into nature, it not only loses precious nutrients, but also provides sufficient nutrients for the reproduction of harmful microorganisms, thereby aggravating the pollution of the environment.

[0003] In recent years, people have mainly applied soy whey in the following ways: (1) by using soy whey as a raw material for extracting functional substances. For example, separating soy isoflavones, soy whey protein and soy oligosaccharides, etc. However, this treatment method still produces a lot of waste during the extraction process and cannot solve the pollution problem of soy whey; (2) using soy whey as a microbial fermentation matrix to prepare lactic acid bacteria fermented beverages. However, the fermentation strains used are mostly transplanted directly from dairy fermentation, and there is a lack of exclusive strains suitable for soy whey fermentation. There are problems such as difficulty in removing the beany smell, strong sour taste, and unclear nutritional function positioning. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a rose physalis enzyme beverage in view of the deficiencies of the prior art. The present invention utilizes the soy whey fermentation-specific strain Lactobacillus plantarum SJ-L-1 isolated from the physalis used in the production of traditional physalis tofu, screens medicinal and edible ingredients with good hedging effects on beany smell, selects rose residue, an industrial byproduct of rose deep processing that is low in cost and also in urgent need of comprehensive utilization, as an auxiliary raw material for soy whey fermentation, and prepares a rose physalis enzyme beverage with a high isoflavone content, providing a highly feasible method for the comprehensive utilization of soy whey.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A preparation method of a rose physalis enzyme beverage, in which soybean whey is mixed with rose residue powder, and a mixed seed solution of Lactobacillus plantarum SJ-L-1 and Saccharomyces cerevisiae is inoculated, and the physalis stock solution is prepared by fermentation.

[0007] The design idea of the present invention: In order to obtain strains with a fast acid production rate and excellent flavor of the fermented physalis beverage, compare the flavors and sensory properties of strains from different sources fermenting to prepare physalis in soybean whey, so as to screen out special strains for the production of physalis beverages; adopt the compound fermentation method of lactic acid bacteria and yeast to reduce the irritating sour taste caused by excessive fermentation of lactic acid bacteria, and at the same time improve the product through the synergistic fermentation of yeast and lactic acid bacteria; screen out medicinal and edible homologous ingredients with good hedging effects on bean odor, and finally select the industrial by-product rose residue of rose deep processing with low cost and also in urgent need of comprehensive utilization as an auxiliary raw material for the fermentation of soybean whey to prepare a rose physalis enzyme beverage with a high isoflavone content.

[0008] Lactobacillus plantarum SJ-L-1 was deposited at the General Microbiological Center of the China Committee for Culture Collection of Microorganisms on July 14, 2022, with the deposit number: CGMCC No. 25209.

[0009] The inoculation amount of the mixed seed solution is 2% v / v, calculated based on the total volume of the mixture of soybean whey and rose residue powder.

[0010] In the mixed seed solution, the ratio of the Lactobacillus plantarum SJ-L-1 seed solution to the Saccharomyces cerevisiae seed solution is 1:1.

[0011] The Lactobacillus plantarum seed solution is prepared as follows: Lactobacillus plantarum SJ-1 is inoculated into 20 mL of broth medium and cultured at 37 °C for 12 h for activation.

[0012] The Saccharomyces cerevisiae seed solution is prepared as follows: Commercial Saccharomyces cerevisiae is inoculated into 20 mL of YPD medium and cultured at 30 °C for 12 h for activation.

[0013] In the present invention, the soybean whey comes from the soybean whey water in the production process of physalis tofu and is treated by concentration and sterilization. For the sterilization treatment, the sterilization temperature is 72 °C and the sterilization time is 30 min.

[0014] The rose residue powder is treated by ultraviolet sterilization. Specifically, the rose residue powder is spread flat in a petri dish, the lid is opened and placed in a clean bench, and irradiated with a 15 W ultraviolet lamp for 30 min for sterilization.

[0015] In one embodiment, the addition ratio of the rose residue powder in the soybean whey is 0.5 g / 100 mL.

[0016] Fermentation conditions: Static culture is carried out at 30 °C for the first 160 h, and the temperature is adjusted to 37 °C in the last 8 h.

[0017] In the present invention, sorbitol, guar gum and sodium citrate are added to the obtained Physalis stock solution, wherein, based on the mass of the stock solution, the added amount of sorbitol is 5.00%, the added amount of guar gum is 0.3%, and the added amount of sodium citrate is 0.20%.

[0018] The invention provides a method for preparing a rose physalis enzyme beverage with a high isoflavone content. The method comprises the following steps: using plant lactobacillus SJ-1 and commercial brewing yeast with soybean whey as a fermentation matrix and using rose dregs powder as an auxiliary agent, thereby helping to increase the isoflavone content and preparing a functional physalis beverage with a high isoflavone content. The method further improves the flavor and taste of the rose physalis enzyme beverage with a high isoflavone content by adjusting the beverage formula, thereby providing a new idea for the comprehensive utilization of soybean whey and rose dregs and having broad application prospects and economic significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The pH changes of soybean whey fermented by six lactic acid bacteria strains.

[0020] Figure 2 The changes in acid production of soybean whey fermented by six lactic acid bacteria strains.

[0021] Figure 3 Response surface plot and contour lines for the interaction between sorbitol addition and guar gum addition on sensory scores.

[0022] Figure 4 Response surface plot and contour plot for the interaction between sorbitol addition amount and sodium citrate addition amount on sensory scores.

[0023] Figure 5 Response surface plot and contour plot for the interaction between guar gum addition and sodium citrate addition on sensory scores.

[0024] Collection information:

[0025] Lactobacillus plantarum SJ-L-1

[0026] Depository: China National Microbiological Culture Collection Administration General Microbiology Center

[0027] Address: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing

[0028] Date of deposit: July 14, 2022

[0029] Deposit number: CGMCC No.25209

[0030] Classification: Lactobacillus plantarum DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0032] In the following embodiments, the experimental methods are conventional methods unless otherwise specified; the reagents and materials can be obtained from commercial sources unless otherwise specified.

[0033] In the following embodiments, the formulation of the MRS solid medium is as follows: peptone 10 g, beef extract powder 3 g, sodium chloride 5 g, agar 15 g, distilled water 1 L, pH 7.3 ± 0.1.

[0034] In the following embodiments, the formulation of the MRS liquid medium is as follows: it only lacks agar, and the other components are the same as those of the MRS solid medium.

[0035] In the following embodiments, the formulation of the modified MRS solid medium is as follows: only 2% calcium carbonate is added, and the other components are the same as those of the MRS solid medium.

[0036] In the following embodiments, the formulation of the YPD medium is as follows: tryptone 20 g, yeast extract powder 10 g, glucose 20 g, distilled water 1000 ml, natural pH.

[0037] The rose residue powder is treated by ultraviolet sterilization. Specifically, the rose residue powder is spread flat in a petri dish, the lid is opened and placed in a clean bench, and irradiated with a 15 W ultraviolet lamp for 30 min for sterilization.

[0038] Example 1 Isolation of Lactic Acid Bacteria Strains from Physalis alkekengi

[0039] Test materials: naturally fermented Physalis alkekengi from a tofu factory in Yanqing, Beijing;

[0040] (1) Activation and proliferation culture of Physalis alkekengi: Take 5 mL of Physalis alkekengi and inoculate it into 20 ml of sterilized soybean whey medium according to a volume ratio of 25% v / v, and statically culture it in a 37°C incubator for 48 h.

[0041] (2) Isolation of strains: Pipette 1 mL of Physalis alkekengi and put it into a centrifuge tube containing 9 mL of normal saline. After vortexing and shaking thoroughly, immediately pipette 1 mL of the suspension and add it to a centrifuge tube containing 9 mL of normal saline. Repeat this step to obtain three dilution gradients of 10-4, 10-5, and 10-6. Since lactic acid bacteria are facultative anaerobes and grow well under anaerobic conditions, the dilution pour plate method (pouring plate method) is used for inoculation. Take 100 μL of the dilution solutions of the above three gradients in blank petri dishes, pour into the MRS broth medium containing 2% CaCO3 that has been melted and cooled to about 45°C, and incubate it upside down in a 37°C constant temperature incubator for 48 h.

[0042] (3) Pick colonies with clear zones and different colony characteristics (colony size, colony color, clear zone size) on the plate, and use the three-zone streaking method to streak and isolate them on MRS solid medium until single colonies appear.

[0043] (4) Observe the growth and morphological differences of the colonies. Pick single colonies with different colony morphologies for Gram staining and microscopic examination of the colony morphology. Select Gram-positive bacteria and transfer them to MRS plates, incubate at 37 °C for 48 h, and pick single colonies and transfer them to slant medium for preservation.

[0044] (5) Prepare seed solutions from the 6 strains of Gram-positive lactic acid bacteria (L-2-1, L-3-1, L-4-1, SJ-L-1, L-7-16, L-1-16) screened in Example 1. After inoculating them into liquid medium and culturing for 12 h, centrifuge at 5000 g for 5 min at 4 °C. Wash the obtained bacterial sludge twice with physiological saline, and then inoculate it into soy whey sterilized at 72 °C for 30 min at a ratio of 2% (v / v). Ferment at 37 °C for 12 h and conduct sensory evaluation to select a lactic acid bacteria strain with good flavor, which is identified as Lactobacillus plantarum SJ-L-1 (hereinafter referred to as SJ-L-1 for short).

[0045] Example 2 Comparison of Acid Production Capabilities of Lactic Acid Bacteria

[0046] (1) Inoculate the 6 strains of lactic acid bacteria (L-2-1, L-3-1, L-4-1, SJ-L-1, L-7-16, L-1-16) screened in Example 1 into MRS liquid medium respectively. After culturing for 24 h, centrifuge at 5000 g for 5 min at 4 °C. Wash the obtained bacterial sludge twice with physiological saline, and then inoculate it into soy whey sterilized at 72 °C for 30 min at a ratio of 2% (v / v). Ferment at 37 °C for 12 h and measure the changes in pH and acid production during the fermentation process.

[0047] (2) The methods for measuring the changes in pH and acid production during the fermentation process are as follows:

[0048] Measurement of pH: Measure the pH of the fermented sour pulp using a pH meter at 25 °C.

[0049] Measurement of acid production: Take 3 ml of the sample in a conical flask, dilute it 10 times with distilled water, use 0.1% phenolphthalein as an indicator, and titrate it with 0.1% mol / L sodium hydroxide solution. When the solution turns pink and does not fade after 30 s, it is regarded as the titration end point. Calculate according to the following formula: X - Content of total acid in the sample (calculated as lactic acid), g / L; c - Concentration of the standard sodium hydroxide titrant, mol / L; V1 - Volume of the standard sodium hydroxide solution consumed in titrating the test solution, ml; V2 - Volume of the standard sodium hydroxide solution consumed in the blank test, ml; 0.09 - Conversion factor of lactic acid; F - Dilution factor of the test solution; V 样 - Volume of the sample, ml; 1000 - Conversion factor.

[0050] (3) The results are as Figure 1 and Figure 2 shown. It can be seen from Figure 1 that within 12 h of lactic acid bacteria fermentation, the pH of soy whey fermented by 6 lactic acid bacteria strains generally shows a downward trend. Among them, before 8 h of fermentation, the overall downward trend is relatively intense, while after 8 h, the downward trend gradually flattens. Among them, the trend changes of SJ-L-1, L-7-16, L-1-16, and L-4-1 are relatively obvious, while the downward change trends of L-3-1 and L-2-1 are relatively gentle. It can be seen from Figure 2 the change in the acid production content of 6 lactic acid bacteria during growth. Starting from the acid production rate, through comparison, it can be clearly seen that during the 12 h period, the acid production rates of all 6 strains show an upward trend. Among them, the acid production rates and acid production amounts of strains SJ-L-1 and L-7-16 are significantly higher than those of other strains. From the total acid production, strains SJ-L-1, L-7-16, and L-4-1 all have obvious advantages. The change trends of strains L-2-1 and L-3-1 are relatively gentle. After 8 h, the acid production amount gradually increases, but compared with other strains, they do not have advantages in terms of acid production rate and acid production amount. At 12 h, their acid production amounts are only 12.00 g / L and 10.25 g / L.

[0051] Example 3 Sensory evaluation of rose physalis

[0052] (1) Inoculate the pre-activated lactic acid bacteria seed liquid and Saccharomyces cerevisiae seed liquid in a sterilized mixed system of 200 ml of rose residue powder and soy whey at a ratio of 1:1. Incubate statically at 30 °C for the first 160 h, and then adjust the temperature to 37 °C for the last 8 h. Conduct sensory evaluation according to Table 1 and the formula, and obtain the total score with the following formula: Sensory score = Appearance * 20% + Odor * 20% + Texture * 40% + Acceptability * 20%.

[0053] The lactic acid bacteria seed liquid is prepared as follows: Inoculate the seed liquid into 20 mL of broth medium and activate and culture it at 37 °C for 12 h.

[0054] The Saccharomyces cerevisiae seed liquid is prepared as follows: Inoculate Saccharomyces cerevisiae into 20 mL of YPD medium and activate and culture it at 30 °C for 12 h.

[0055] Table 1 Sensory evaluation scoring criteria for rose physalis beverage

[0056]

[0057]

[0058] Table 2 Sensory evaluation scores of 6 kinds of Physalis alkekengi rose beverages

[0059] Appearance Flavor Texture SJ-L-1 + Saccharomyces cerevisiae 90 87 93 L-2-1 + Saccharomyces cerevisiae 88 80 85 L-3-1 + Saccharomyces cerevisiae 85 82 85 L-4-1 + Saccharomyces cerevisiae 85 85 85 L-7-16 + Saccharomyces cerevisiae 90 85 86 L-1-16 + Saccharomyces cerevisiae 85 82 85

[0060] (2) Through the combined fermentation of different strains, it was found that the combination of SJ-L-1 and Saccharomyces cerevisiae could obtain better flavor and taste, which might be the synergistic effect of the two strains. To further verify the results, the separate fermentation effects of SJ-L-1 and Saccharomyces cerevisiae were continued to be investigated. The pre-activated lactic acid bacteria and Saccharomyces cerevisiae were separately inoculated and inoculated at a ratio of 1:1 into the sterilized mixed system of 200 ml of rose residue powder and soybean whey. The mixture was statically cultured at 30 °C for the first 160 h, and the temperature was adjusted to 37 °C for the last 8 h. The sensory evaluation was carried out according to Table 1 and the formula, and the total score was obtained by the following formula: Sensory score = Appearance * 20% + Odor * 20% + Texture * 40% + Acceptability * 20%. It can be seen that the separate fermentation effect of either lactic acid bacteria or yeast is not as good as that of mixed fermentation.

[0061] Appearance Flavor Texture SJ-L-1 + Saccharomyces cerevisiae 90 87 93 SJ-L-1 88 80 85 Saccharomyces cerevisiae 85 82 85

[0062] (2) Determination of isoflavone content

[0063] For the above-mentioned single-strain fermentation and mixed-strain fermentation rose Physalis alkekengi beverages of SJ-L-1 and Saccharomyces cerevisiae and the unfermented samples, 1 mL of each sample was mixed with 4 mL of 80% (v / v) methanol and ultrasonically extracted for 60 min. The extract was centrifuged at 10000 rpm and 4 °C for 10 min, and the supernatant was collected. The tofu samples were freeze-dried, and 10 mL of 80% ethanol was added to each gram of the freeze-dried product for re-dissolution, and ultrasonically extracted at room temperature for 6 h with an ultrasonic power of 70 w. The extract was centrifuged at 10000 rpm and 4 °C for 10 min. The ethanol in the supernatant of the ethanol extract was evaporated to dryness with a rotary evaporator, and the remaining liquid was re-dissolved to 10 mL with 80% methanol. The supernatant was filtered through a 0.22 μm filter membrane, and the isoflavone content was analyzed by high performance liquid chromatography, with three parallel determinations.

[0064] Chromatographic conditions: The chromatographic column was a Shimadzu AQ-C18 column (4.6 × 250 mm, 5 μm); the mobile phase was 0.5% (v / v) aqueous acetic acid solution (A) and 100% acetonitrile (B); the flow rate was 0.6 mL / min; the column temperature was 30 °C; the detection wavelength was 260 nm; the injection volume was 15 μL; the gradient elution conditions were shown in Table 6.

[0065] The contents of isoflavones in Physalis alkekengi L. var. franchetii (Mast.) Makino and its fermented samples are shown in Table 3. The main form of isoflavones in the unfermented samples of Physalis alkekengi L. var. franchetii (Mast.) Makino is conjugated glycosides. The fermentation process causes the conjugated glycosides in the system to gradually transform into aglycones, with the content of conjugated glycosides decreasing and the content of aglycones increasing significantly. This is related to the large amount of β-glucosidase in SJ-L-1. β-glucosidase can hydrolyze the glycoside structure of soybean isoflavones in soymilk and transform them into aglycone forms with higher biological activity, thus improving the bioavailability of soybean isoflavones. Combining SJ-L-1 with Saccharomyces cerevisiae to produce a fermented beverage with a high content of aglycone-type isoflavones greatly improves the nutritional value of the beverage.

[0066] Physalis alkekengi L. var. franchetii (Mast.) Makino and its fermented samples contain a large amount of daidzein and genistein, accounting for 41.17% and 44.70% of the total isoflavone content, respectively. Daidzein and genistein have strong DPPH and hydroxyl radical scavenging abilities, can protect cells from the destructive effects of free radicals, and have good antioxidant activity. In addition, daidzein and genistein also play a dominant role in the anti-cancer activity of soybeans.

[0067] Table 3 Soybean isoflavone content in Physalis alkekengi L. var. franchetii (Mast.) Makino beverage

[0068]

[0069] Example 4 Single-factor experiment on the formula of Physalis alkekengi L. var. franchetii (Mast.) Makino

[0070] (1) The pre-activated SJ-L-1 and Saccharomyces cerevisiae were mixed and inoculated into a sterilized 200 ml mixed system of rose residue and soybean whey at an inoculation amount of 2%. They were statically cultured at 30 °C for the first 160 h, and the temperature was adjusted to 37 °C for the last 8 h to obtain the original solution of Physalis alkekengi L. var. franchetii (Mast.) Makino beverage.

[0071] (2) For the original solution in the above step (1), with the addition amount of guar gum fixed at 0.30% and the addition amount of sodium citrate fixed at 0.20%, the addition amounts of sorbitol were set at 3.5%, 4.5%, 5.5%, and 6.5% respectively. Sensory evaluation was carried out, and the standard is shown in Table 4 to determine its addition amount, and the standard is shown in Table 1.

[0072] (3) For the Physalis alkekengi L. var. franchetii (Mast.) Makino in the above step (1), with the addition amount of sorbitol fixed at 4.5% and the addition amount of sodium citrate fixed at 0.20%, the addition amounts of guar were set at 0.20%, 0.25%, 0.30%, and 0.40% respectively, and the centrifugal precipitation rate was determined to determine its addition amount.

[0073] (4) For the Physalis alkekengi L. var. franchetii (Mast.) Makino in the above step (1), with the addition amount of sorbitol fixed at 4.5% and the addition amount of guar gum fixed at 0.30%, the addition amounts of sodium citrate were set at 0.10%, 0.15%, 0.2%, and 0.25% respectively. Sensory evaluation was carried out, and the standard is shown in Table 5 to determine its addition amount.

[0074] Table 4 Sensory Evaluation Scoring Criteria for Sorbitol Additive

[0075]

[0076] Table 5 Sensory Evaluation Scoring Criteria for Sodium Citrate Additive

[0077]

[0078]

[0079] Example 5 Response Surface Optimization Experiment of Rose Physalis Formula

[0080] (1) In the single-factor experiment, there was an obvious interaction among the addition amounts of sorbitol, guar gum, and sodium citrate. Therefore, a response surface experiment was carried out for optimization subsequently.

[0081] (2) Taking the optimal level of the single factor as the center point and considering the influence of the interaction, a 3-factor 3-level test group was designed by the central composite design. Taking the addition amount of sorbitol (A), the addition amount of guar gum (B), and the addition amount of sodium citrate (C) as evaluation factors and the sensory score as the only response value, the experimental results were used to construct a response surface model through Design Expert 8.0, and the corresponding quadratic polynomial equation and the best additive formula were obtained. A Box-Behnken central composite test was carried out. There were 17 test points in total, including 5 central test points and 12 factorial test points. The results are shown in Table 4.

[0082] Table 6 Response Surface Analysis

[0083]

[0084]

[0085] (3) Using the system software Design-Expert 8.0 to perform quadratic multiple regression fitting on the experimental data, carrying out data analysis through the response surface regression process, establishing a quadratic response surface regression model, and seeking the optimal corresponding factor levels, the regression equation was obtained: Y = 84.66 + 2.28A - 3.86B + 1.38C + 0.25AB - 0.58AC + 0.19BC - 2.54A 2 - 4.97B 2 - 5.10C 2

[0086] (4) Variance analysis was carried out on the regression model in step (3). The results showed that the linear correlation of the regression model was extremely significant (P < 0.0001). The R of the regression model 2= 0.9706, lack of fit term P = 0.1330 > 0.05, not significant, indicating that the regression model fully fits the experimental results, and this model can be used to analyze and predict the sensory evaluation results. In the regression model, the linear terms of factors A and B are highly significant (P < 0.01), the linear term of factor C is significant (P < 0.05), and the quadratic terms of A, B, and C are all highly significant (P < 0.01). By comparing the F values, it can be seen that among the three single factors, the order of influence on the sensory evaluation of the sample is: guar gum content > sorbitol content > sodium citrate.

[0087] (4) Using Design Expert 8.0, the response surface and contour plots of the interaction effects of the three experimental factors, namely the addition amount of sorbitol (A), the addition amount of guar gum (B), and the addition amount of sodium citrate (C), on the sensory evaluation (Y value) of lactic acid bacteria-fermented soybean whey beverage are shown in Figures a, b, and c. By observing the three-dimensional response surface graph between the factors, the strength of the interaction between the factors can be observed, and it can also reflect the strength of the influence of each interaction on the response value. The steeper the curve in the contour plot, the more significant the influence; the smoother the curve, the weaker the influence. In addition, the shape of the contour plot can reflect the interaction effect of each factor on the response value. When the contour plot is elliptical, it indicates that the interaction is significant, while when the contour plot is circular, the interaction is not significant. The shape change of the three-dimensional response surface graph represents the change of the response value.

[0088] (5) As shown in Figure 3 , under the condition that the addition amount of sodium citrate is 0.20%, the influence of the addition amount of guar gum on the addition amount of sorbitol was studied; as shown in Figure 4 , under the condition that the addition amount of guar gum is 0.33%, the influence of the addition amount of sodium citrate on the addition amount of sorbitol was studied; as shown in Figure 5 , under the condition that the addition amount of sorbitol is 4.5%, the influence of the addition amount of citric acid on the addition amount of guar gum was studied.

[0089] It can be seen from the 3D graph that the response surface curve trend of the interaction effect between the factors on the result is relatively steep, and the contour plot is elliptical, indicating that there are interactions between AB, AC, and BC. According to the steepness of the surface, it is obtained that the addition amount of guar gum has a greater influence on the sensory score of lactic acid bacteria-fermented soybean whey, followed by the addition amount of sorbitol and the addition amount of sodium citrate.

[0090] (5) Using the Design-Expert 8.0 software, with the maximum sensory score as the experimental objective, the response surface results were analyzed. The optimal process parameters were obtained as follows: when the sorbitol content was 4.92%, the guar gum content was 0.30%, and the sodium citrate was 0.20%, the sensory score was 85.9335. To determine the feasibility of the results and for actual operation, the optimal fermentation process conditions were modified to: the sorbitol addition amount was 5.00%, the guar gum addition amount was 0.3%, and the sodium citrate addition amount was 0.20%. Under these process conditions, three parallel experiments were conducted, and the sensory score obtained was 86.34.

[0091] The experimental results were in good agreement with the theoretical predicted values, indicating that the proposed optimal addition amounts were reliable. Therefore, the process conditions of the rose physalis beverage optimized by the response surface method were accurate and reasonable, and had reference significance for the actual production of enterprises.

Claims

1. A preparation method of a rose physalis enzyme beverage, characterized in that Soybean whey is mixed with rose residue powder, and a mixed seed solution of Lactobacillus plantarum SJ-L-1 and Saccharomyces cerevisiae is inoculated for fermentation to prepare the original acid pulp solution.

2. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, The inoculation amount of the mixed seed solution is 2% v / v.

3. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1 or 2, characterized in that, In the mixed seed solution, the ratio of the Lactobacillus plantarum SJ-L-1 seed solution to the Saccharomyces cerevisiae seed solution is 1:

1.

4. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 3, characterized in that, The Lactobacillus plantarum seed solution is prepared as follows: The Lactobacillus plantarum SJ-1 is inoculated into 20 mL of broth medium and activated and cultured at 37 °C for 12 h.

5. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, The Saccharomyces cerevisiae seed solution is prepared as follows: The Saccharomyces cerevisiae is inoculated into 20 mL of YPD medium and activated and cultured at 30 °C for 12 h.

6. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, The soybean whey comes from the soybean whey water in the production process of acid pulp tofu and is subjected to concentration and sterilization treatment; the sterilization treatment conditions: the sterilization temperature is 72 °C and the sterilization time is 30 min.

7. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, The rose residue powder is treated by ultraviolet sterilization.

8. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, The addition ratio of the rose residue powder in the soybean whey is 0.5 g / 100 mL.

9. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, Fermentation conditions: Static culture is carried out at 30 °C for the first 160 h, and the temperature is adjusted to 37 °C in the last 8 h.

10. The preparation method of the Physalis alkekengi L. var. franchetii (Mast.) Makino enzyme beverage according to claim 1, characterized in that, In the obtained original acid pulp solution, sorbitol, guar gum and sodium citrate are added; among them, calculated by the mass of the original solution, the addition amount of sorbitol is 5.00%, the addition amount of guar gum is 0.3%, and the addition amount of sodium citrate is 0.20%.

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