Probiotic-fermented low-sugar Chinese wolfberry primary pulp or Chinese wolfberry clear juice and preparation method of probiotic-fermented low-sugar Chinese wolfberry primary pulp or Chinese wolfberry clear juice

Abstract

The invention belongs to the technical field of food biology, and particularly relates to probiotic fermented low-sugar Chinese wolfberry primary pulp or Chinese wolfberry clear juice and a preparation method thereof. According to the invention, the plant lactobacillus SV04 is used for fermenting the Chinese wolfberry primary pulp and the concentrated clear juice, and the physicochemical indexes and the change of main active components of the probiotic fermented Chinese wolfberry primary pulp and the concentrated clear juice are detected. The fermented product has the characteristics of low sugar, moderate sour and sweet taste and unique flavor, not only retains abundant nutrients and natural components of the Chinese wolfberry fruits, but also provides safer and healthier drink choices for diabetics and people with low sugar requirements through the hypoglycemic effect of the probiotics, and shows a wide application prospect of a food biotechnology in the field of nutrition and health.

Description

Technical field:

[0001] The invention belongs to the field of food biotechnology, and particularly relates to a probiotic fermented low-sugar wolfberry puree or wolfberry juice and a preparation method thereof. Background technology:

[0002] Lycium barbarum, goji, also known as wolfberry, is the fruit of a plant in the Solanaceae family. It is a traditional medicinal material and health food material, rich in nutrients such as polysaccharides, amino acids, vitamins and trace elements, and has the effects of anti-tumor, lowering blood sugar, strengthening the body, nourishing the liver and kidneys, and improving sperm quality and eyesight.

[0003] Wolfberry puree refers to the concentrated liquid directly squeezed or extracted from wolfberry fruit. It retains the rich nutrients in wolfberry, such as wolfberry polysaccharides, amino acids, vitamins and minerals, so it has a thicker and sweeter taste. Fresh wolfberry puree has a sweet and sour taste. The sweetness of fresh wolfberry puree varies greatly due to the variety and origin. Wolfberry concentrated juice is a concentrated liquid extracted from wolfberry fruit through a certain hydrolysis or juicing process. The pulp and impurities are usually removed. It has a fresh, light taste and a higher sweetness, but it retains the rich nutrients of wolfberry. Compared with wolfberry puree, its concentration and viscosity are lower, and it is usually suitable for people who like a refreshing taste.

[0004] Probiotics have excellent probiotic effects, which can improve the structure of intestinal flora and promote the digestion and absorption of nutrients. They can regulate the intestinal ecological balance, improve intestinal immune function, inhibit the occurrence of pathogenic microorganisms, and maintain intestinal health. In recent years, probiotic fermentation technology has been widely used in the field of food and health care product processing. Probiotic fermentation can not only improve the taste and texture of food, but also effectively promote the synthesis and transformation of certain beneficial ingredients.

[0005] In view of the rapid development of the plant-based lactic acid bacteria beverage market, fermented wolfberry beverages may become a product with development prospects. With the improvement of people's health awareness, whether food is low in sugar has become one of the important considerations affecting consumer purchasing power. Most wolfberry purees and juices on the market have high sugar content, which is not suitable for diabetics and people with low sugar needs, and affects the quality and sales of the product. Moreover, the current blood sugar lowering effect of wolfberry juice fermented with lactic acid bacteria is poor, which cannot meet the current demand for low-sugar wolfberry juice in the functional health food and beverage industry. Therefore, it is a major challenge facing the wolfberry industry to explore a new probiotic strain with high blood sugar lowering effect, and develop a new low-sugar wolfberry puree and wolfberry juice based on it, and maximize the retention of more of its natural ingredients while improving the health value of the product.

[0006] The present invention focuses on screening and exploring effective blood sugar-lowering probiotic strains and developing low-sugar wolfberry puree and clear juice products. This product not only retains the rich nutrition of wolfberry, but also provides a safer and healthier beverage choice for diabetic patients and people with low-sugar needs through the blood sugar-lowering effect of probiotics, showing the broad application prospects of food biotechnology in the field of nutrition and health. Summary of the invention:

[0007] To solve the above problems, the present invention discovered a probiotic strain with significant blood sugar lowering effect through precise screening and functional verification, and then combined with modern food processing technology, these probiotics were integrated with high-quality wolfberry raw materials to innovatively develop a low-sugar wolfberry juice product.

[0008] The technical solution provided by the present invention is to use a plant lactobacillus SV04 to ferment wolfberry puree and concentrated juice to achieve a hypoglycemic effect while retaining the nutrients in the wolfberry.

[0009] The name of the plant lactobacillus is SV04, the classification name is plant lactobacillus (Lactiplantibacillus plantarum), the corresponding preservation number is CGMCC No.33118, the preservation date is December 18, 2024, and the preservation unit is the General Microbiology Center of China National Microbiological Culture Collection Administration, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0010] Furthermore, the steps of fermenting low-sugar wolfberry puree and wolfberry juice with Lactobacillus plantarum SV04 are as follows:

[0011] First, the prepared wolfberry puree and wolfberry concentrated juice were sterilized at 85°C for 20 minutes to inactivate enzymes and harmful bacteria in the wolfberry juice. After cooling, the activated Lactobacillus plantarum SV04 bacterial solution was inoculated into the sterilized and cooled wolfberry puree and wolfberry concentrated juice at an inoculum volume of 3% (v / v) (Lactobacillus plantarum SV04 was 2.2×10 8 CFU / mL). The wolfberry puree and wolfberry concentrated juice were fermented at 37℃ for 48h with a ratio of 1:0 and 1:3 respectively, and the physical and chemical values ​​before and after fermentation were tested.

[0012] Furthermore, the physicochemical indexes and main active ingredients of the probiotic fermented wolfberry puree and clear juice were tested:

[0013] (1) pH value during fermentation: After 48 h, the pH values ​​of fermented and unfermented wolfberry puree and wolfberry concentrated juice were measured.

[0014] (2) Determination of total acid: After 48 hours, the total acid content of the product was determined by acid-base titration. The total acid content was determined in accordance with GB12456-2021.

[0015] (3) Determination of total sugar and reducing sugar content: The polysaccharide content was determined by the phenol-sulfuric acid method. A glucose standard curve was prepared to determine the total sugar and reducing sugar.

[0016] Furthermore, the pH, acidity, total sugar and reducing sugar in wolfberry puree and wolfberry juice before and after fermentation were compared.

[0017] Preferably, the probiotic fermented low-sugar fresh wolfberry puree and wolfberry concentrated juice have the characteristics of low sugar, low acidity and unique flavor, and can be used as a healthy and nutritious drink, and can also satisfy the drinking needs of people pursuing a low-sugar diet.

[0018] Beneficial effects:

[0019] The Lactobacillus plantarum SV04 used in the present invention is a probiotic strain with significant blood sugar lowering effect. Using the strain to ferment wolfberry puree and wolfberry concentrated juice can effectively reduce the sugar content in the wolfberry juice, and prepare a low-sugar, low-calorie wolfberry beverage to meet the needs of diabetic patients, obese people and healthy diet consumers.

[0020] The present invention uses probiotic fermentation to enhance the probiotic content in wolfberry puree and concentrated juice, so that the product contains active probiotics and active substances such as short-chain fatty acids, improves intestinal microecological environment, enhances immune function, and has significant health care effects.

[0021] The present invention uses probiotics to ferment wolfberry juice. The probiotic fermentation process gives the wolfberry juice a unique flavor and retains the nutrients in the wolfberry to the maximum extent. At the same time, the bioavailability of some components is improved, so that the nutritional value of the final product is higher.

[0022] The preparation method of the present invention has innovative process, simple operation, and is easy for large-scale production, which helps to reduce production costs and improve production efficiency, and has significant market application prospects and social and economic benefits. Description of the drawings:

[0023] Figure 1 The change of pH value during the fermentation process of the present invention

[0024] A is the change in pH value of wolfberry puree before and after fermentation with different material-liquid ratios, and B is the change in pH of wolfberry concentrated juice before and after fermentation with different material-liquid ratios.

[0025] Figure 2 The change of total acid in the fermentation process of the present invention

[0026] Among them, A is the change of total acidity in wolfberry puree before and after fermentation with different material-liquid ratios, and B is the change of total acidity in wolfberry concentrated juice before and after fermentation with different material-liquid ratios.

[0027] Figure 3 The change of total sugar in the fermentation process of the present invention

[0028] Among them, A is the change of total sugar in wolfberry puree before and after fermentation with different material-liquid ratios, B is the percentage reduction of total sugar in wolfberry puree with different material-liquid ratios, C is the change of total sugar in wolfberry concentrated juice with different material-liquid ratios before and after fermentation, and D is the percentage reduction of total sugar in wolfberry concentrated juice with different material-liquid ratios.

[0029] Figure 4 The change of reducing sugar in the fermentation process of the present invention

[0030] Among them, A is the change of reducing sugar in wolfberry puree before and after fermentation with different material-liquid ratios, B is the percentage reduction of reducing sugar in wolfberry puree with different material-liquid ratios, C is the change of reducing sugar in wolfberry concentrated juice with different material-liquid ratios before and after fermentation, and D is the percentage reduction of reducing sugar in wolfberry concentrated juice with different material-liquid ratios. Specific implementation method:

[0032] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings and examples. The examples are used to illustrate the present invention but do not limit the scope of the present invention.

[0033] The example of the present invention proposes to use Lactobacillus plantarum SV04 to ferment low-sugar fresh wolfberry puree and wolfberry concentrated juice.

[0034] In the present invention, the name of the plant lactobacillus is SV04, the classification name is plant lactobacillus (Lactiplantibacillus plantarum), the corresponding preservation number is CGMCC No.33118, the preservation date is December 18, 2024, and the preservation unit is the General Microbiology Center of China National Committee for the Preservation of Microorganisms, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0035] Furthermore, the indicators of the product are further explained below with reference to examples.

[0036] Example 1: Preparation of low-sugar wolfberry juice fermented by probiotics

[0037] (1) The prepared wolfberry puree and wolfberry concentrated juice are sterilized at 85°C for 20 min.

[0038] (2) The preserved culture of Lactobacillus plantarum SV04 was taken out and thawed, activated and rejuvenated on an MRS plate, inoculated into the bacterial solution, and cultured in a 37° C. constant temperature incubator for 24 h.

[0039] (3) The activated bacterial solution was inoculated into the sterilized and cooled wolfberry puree and wolfberry concentrated juice at an inoculum volume of 3% (v / v) (2.2×10 8CFU / mL).

[0040] (4) The mass ratios of wolfberry puree and wolfberry concentrated juice to water are 1:0 and 1:3, respectively. The material-liquid ratio in wolfberry juice is controlled between 1:1 and 1:3, which can ensure the growth of probiotics without over-diluting the nutrients in the wolfberry juice.

[0041] (5) The fermentation was carried out at 37°C for 48 h, and the number of viable bacteria in the fermented wolfberry puree was 7.6×10 9 CFU / mL, the number of viable bacteria in the fermented wolfberry concentrated juice was 1.2×10 9 CFU / mL.

[0042] (6) The wolfberry juice without bacterial inoculation was used as the unfermented wolfberry juice, and the physical and chemical indices of the wolfberry juice before and after fermentation were measured.

[0043] Example 2: Physical and chemical index detection of low-sugar wolfberry juice fermented by probiotics

[0044] (1) Determination of pH value

[0045] In the present invention, the activated plant lactobacillus SV04 bacterial liquid is inoculated into the sterilized and cooled wolfberry puree and wolfberry concentrated clear juice, the wolfberry juice is fermented, and the pH value of the wolfberry juice after fermentation for 48 hours is measured. pH value and acidity are important indicators for evaluating lactic acid bacteria fermentation, which are often used to characterize the acid production ability of lactic acid bacteria and reflect their growth and metabolic processes to a certain extent. pH value has an important influence on the taste, mouthfeel and shelf life of food, and a suitable pH value helps to optimize the flavor of the product.

[0046] like Figure 1 As shown in part A, after 48h, the pH values ​​of wolfberry juice without Lactobacillus plantarum SV04 fermentation at different solid-liquid ratios (1:0 and 1:3) were 4.41 and 4.53, respectively. The pH value of wolfberry juice fermented by Lactobacillus plantarum SV04 decreased to a certain extent, and the pH values ​​dropped to 3.21 and 3.01, respectively.

[0047] As shown in part B, after 48 h, the pH values ​​of wolfberry juice concentrate without Lactobacillus plantarum SV04 fermentation at different solid-liquid ratios (1:0 and 1:3) were 4.24 and 4.36, respectively. The pH value of wolfberry juice concentrate fermented with Lactobacillus plantarum SV04 decreased to a certain extent, and the pH values ​​dropped to 4.07 and 3.25, respectively.

[0048] Among them, the pH value of wolfberry juice with a solid-liquid ratio of 1:3 after fermentation with Lactobacillus plantarum SV04 decreased more significantly than that of wolfberry juice with a solid-liquid ratio of 1:0, which indicates that during the fermentation process, wolfberry concentrated juice will have a direct impact on the reduction of pH value.

[0049] (2) Determination of total acid

[0050] During the fermentation process, in addition to the change in pH value, total acid is also an important indicator to measure the acidity of fermented wolfberry juice, reflecting the total amount of acidic substances produced during the probiotic fermentation process. During the fermentation process, probiotics metabolize to produce acidic substances, which leads to a decrease in pH value and affects the flavor and health effects of the final product. The total acid is determined by acid-base titration in accordance with GB12456-2021. The total acid content of the product is determined after 48 hours.

[0051] like Figure 2 As shown, by measuring the fermented wolfberry juice, the present invention found that within a 48-hour fermentation period, when the material-liquid ratio was 1:0, the acidity of the wolfberry puree and wolfberry concentrated juice fermented without lactic acid bacteria was 5.67g / L and 8.64g / L respectively. The acidity of the wolfberry juice fermented by Lactobacillus plantarum SV04 increased significantly, wherein the acidity of the wolfberry puree and wolfberry concentrated juice was 8.96g / L and 11.96g / L respectively, which increased by 58.02% and 38.42% respectively.

[0052] When the material-liquid ratio was 1:3, the acidity of wolfberry puree and wolfberry concentrated juice without lactic acid bacteria fermentation was 2.24g / L and 3.84g / L respectively. However, the acidity of wolfberry juice fermented by Lactobacillus plantarum SV04 increased significantly, with the acidity of wolfberry puree and wolfberry concentrated juice being 8.92g / L and 8.64g / L respectively, up 298.21% and 125.00% respectively.

[0053] These data show that the addition of lactic acid bacteria significantly increases the acidity of wolfberry juice. By controlling the generation of total acid, the taste, flavor and health effects of wolfberry juice can be precisely regulated, providing an important basis for optimizing the fermentation process and adjusting the fermentation conditions. In addition, the total acid of wolfberry juice increased after fermentation, which is consistent with the decrease in pH value, further confirming that lactic acid bacteria fermentation can effectively increase the acidity of wolfberry juice.

[0054] (3) Determination of total sugar

[0055] Sugar content is achieved by controlling sugar metabolism during the fermentation process. Total sugar determination can help study and control changes in sugars during the fermentation process and further understand the product quality of wolfberry juice. During the fermentation process, lactic acid bacteria can effectively use the sugars in wolfberry juice for metabolic activities, thereby reducing the total sugar content in wolfberry juice.

[0056] The polysaccharide content was determined by the phenol-sulfuric acid method. Accurately weigh 10 mg of anhydrous glucose and prepare a 0.1 mg / mL glucose standard solution. Use a pipette to draw 0 mL, 0.2 mL, 0.4 mL, 0.6 mL, 0.8 mL and 1.0 mL of the standard solution into test tubes 0, 1, 2, 3, 4 and 5, and add distilled water to 1.0 mL. Three groups of parallel experiments were performed. Add 0.5 mL of 6% phenol solution, then add 2.5 mL of concentrated sulfuric acid, and leave at room temperature for 20 minutes. Use a visible spectrophotometer and use tube 0 as a blank control to measure the absorbance at a wavelength of 490 nm. Draw a standard curve with the mass concentration of glucose as the horizontal axis and the absorbance value A490nm as the vertical axis. After the sample is diluted to an appropriate multiple, the absorbance is measured at 490 nm. The glucose concentration is calculated according to the standard curve, and the total sugar content is obtained by multiplying the dilution multiple. Using glucose as the standard product, the standard curve y=0.0086x+0.176, R 2 =0.9997.

[0057] like Figure 3 As shown in the figure, when the solid-liquid ratio was 1:0, the total sugar content of wolfberry puree and concentrated juice fermented without lactic acid bacteria was 32.18 mg / mL and 68.16 mg / mL respectively. The total sugar content of wolfberry puree and concentrated juice fermented by Lactobacillus plantarum SV04 was 19.29 mg / mL and 48.59 mg / mL respectively, down 40.05% and 28.71%.

[0058] When the solid-liquid ratio was 1:3, the total sugar content in the wolfberry puree and concentrated juice fermented without lactic acid bacteria was 10.97 mg / mL and 24.66 mg / mL, respectively. The total sugar content in the wolfberry puree and concentrated juice fermented by Lactobacillus plantarum SV04 was 4.09 mg / mL and 11.95 mg / mL, respectively, which decreased by 62.71% and 51.54%.

[0059] These results show that the total sugar reduction effect of Lactobacillus plantarum SV04 in wolfberry puree can reach 62.71%, and the total sugar reduction effect in wolfberry concentrated juice can reach 51.54%, and the 1:3 liquid ratio is more significant. The total sugar reduction effect is significantly better than the currently reported technology.

[0060] The role of total sugar determination in probiotic fermented low-sugar wolfberry juice cannot be ignored. It can not only help monitor the changes in sugar content during the fermentation process, but also optimize the fermentation conditions, ensure the quality and health functions of the product, and provide valuable data support and basis for process adjustment.

[0061] (4) Determination of reducing sugar

[0062] During the fermentation process, the change of reducing sugar is another important indicator to measure the fermentation quality of wolfberry juice. By measuring the content of reducing sugar in fermented wolfberry juice, we can understand the consumption of sugars by probiotics, help control the sugar conversion efficiency during the fermentation process, and optimize the quality and functional characteristics of the final product.

[0063] Take 1 mL of the prepared reducing sugar hydrolyzate, add 2 mL of DNS reagent, boil in a boiling water bath for 5 minutes, take out, and cool to room temperature with tap water. The rest of the operation is the same as the standard curve operation, and the absorbance of each tube is measured at 540 nm.

[0064] Prepare a glucose standard curve: Take a clean centrifuge tube or test tube, adjust it to zero with No. 0, detect the absorbance at 540nm, and plot the standard curve with the absorbance as the ordinate and the standard concentration (mg / mL) as the abscissa.

[0065] Reducing sugar determination: Take 1 mL of the prepared reducing sugar extract or total sugar hydrolyzate, add 2 mL of DNS reagent respectively, and perform the rest of the operation as the standard curve, and measure the absorbance of each tube at 540 nm. y=0.7168x+0.0318, R 2 =0.9995.

[0066] like Figure 4 The results showed that when the solid-liquid ratio was 1:0, the reducing sugar content of wolfberry puree and concentrated juice without lactic acid bacteria fermentation was 8.21 mg / mL and 16.23 mg / mL, respectively. After fermentation with Lactobacillus plantarum SV04, the reducing sugar content of wolfberry puree and concentrated juice decreased to 6.64 mg / mL and 14.41 mg / mL, respectively, a decrease of 19.12% and 11.21%. These data show that Lactobacillus plantarum SV04 fermentation can reduce the reducing sugar content in wolfberry juice to a certain extent.

[0067] When the solid-liquid ratio was 1:3, the reducing sugar content of wolfberry puree and concentrated juice without lactic acid bacteria fermentation was 2.81 mg / mL and 7.46 mg / mL, respectively. After fermentation with Lactobacillus plantarum SV04, the reducing sugar content of wolfberry puree and concentrated juice decreased to 1.82 mg / mL and 5.89 mg / mL, respectively, a decrease of 35.23% and 21.04%.

[0068] These results show that Lactobacillus plantarum SV04 can reduce reducing sugar by 35.23% in wolfberry puree and by 21.04% in wolfberry concentrated juice, and its effect in reducing total reducing sugar is significantly better than that of currently reported technologies.

[0069] These results further confirmed the positive effect of lactic acid bacteria fermentation on reducing the reducing sugar content in wolfberry juice, and Lactobacillus plantarum SV04 showed high efficiency in this process. The determination of reducing sugar is of great significance in probiotic fermentation of low-sugar wolfberry juice, which can not only help monitor the sugar consumption during the fermentation process, but also optimize the fermentation conditions to ensure the flavor, taste and health benefits of low-sugar wolfberry juice.

[0070] The above is only a preferred embodiment of the present invention, and its description is more specific and detailed, but it is not intended to limit the scope of the present invention. The present invention is applicable to the field of probiotic fruit and vegetable fermentation. It should be pointed out that any modification, equivalent replacement, improvement, etc. made within the principle and spirit of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the claims.

Claims

1. A probiotic fermented low-sugar wolfberry puree or wolfberry juice and a preparation method thereof, characterized in that: The method comprises the following steps: (1) Sterilize the prepared wolfberry puree or wolfberry concentrated juice at 85°C for 20 minutes (2) The preserved strain culture of Lactobacillus plantarum SV04 was taken out and thawed, activated and rejuvenated on an MRS plate, inoculated into the bacterial solution, and placed in a 37°C constant temperature incubator for 24 hours. (3) The activated bacterial solution was inoculated into the sterilized and cooled wolfberry puree or wolfberry concentrated juice at an inoculum rate of 3%, and the inoculum rate of Lactobacillus plantarum SV04 was 2.2×10 8 CFU / mL (4) The fermentation was carried out at 37°C for 48 h, and the number of viable bacteria in the fermented wolfberry puree was 7.6×10 9 CFU / mL, the number of viable bacteria in the fermented wolfberry concentrated juice was 1.2×10 9 CFU / mL (5) The wolfberry juice without bacterial inoculation was used as the unfermented wolfberry juice, and the physical and chemical indices of the wolfberry juice before and after fermentation were measured.

2. The name of the plant lactobacillus is SV04, the classification name is plant lactobacillus (Lactiplantibacillus plantarum), the corresponding preservation number is CGMCC No.33118, the preservation date is December 18, 2024, and the preservation unit is the General Microbiology Center of China National Microbiological Culture Collection Administration, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

3. According to claims 1 and 2, it is characterized in that The Lactobacillus plantarum SV04 is a live bacterium.

4. According to claims 1 to 3, it is characterized in that: The fermented beverage comprises an effective amount of live Lactobacillus plantarum SV04 bacteria and wolfberry puree or wolfberry concentrated juice.

5. The preparation method according to claim 1, wherein the mass ratio of the wolfberry puree to water is 1:0 or 1:

3. 6 . The preparation method according to claim 1 , wherein the mass ratio of the wolfberry concentrated juice to water is 1:0 or 1:

3.

7. A probiotic fermented low-sugar wolfberry puree, characterized in that: The low-sugar wolfberry puree is obtained by the preparation method described in claims 1 to 3, and has a significant blood sugar lowering effect after being fermented by Lactobacillus plantarum SV04. The low-sugar wolfberry puree has the characteristics of low sugar, moderate sweetness and sourness, and unique flavor. It can be used as a healthy and nutritious drink, and can also satisfy people who pursue a low-sugar diet.

8. A probiotic fermented low-sugar wolfberry juice, characterized in that: The low-sugar wolfberry juice is prepared by the preparation method described in claims 1 to 3, and has a significant blood sugar lowering effect after being fermented by Lactobacillus plantarum SV04. The low-sugar wolfberry juice has the characteristics of low sugar, moderate sweetness and sourness, and unique flavor. It can be used as a healthy and nutritious drink, and can also satisfy people who pursue a low-sugar diet.

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