A small white apricot probiotic plant-based fermented beverage and a preparation method thereof

Abstract

The present application belongs to the field of food processing, and particularly relates to a small white apricot probiotic plant-based fermented beverage and a preparation method thereof. The optimal fermentation conditions of the milk beverage are as follows: the fermentation temperature is 37 DEG C, the fermentation time is 8 h, the inoculation amount is 10%, and the ratio of small white apricot to drinking water is 1:2. The fermented beverage prepared under the conditions has rich aroma, uniform organization, delicate and sour and sweet taste, and strong antioxidant property.

Description

Technical Field

[0001] This invention belongs to the field of food processing, specifically relating to a plant-based fermented beverage made from white apricot probiotics and its preparation method. Background Technology

[0002] Although products such as dried apricots, apricot jam, and apricot juice have been developed in the market, the overall market is still dominated by raw material sales and primary processing, with low deep processing conversion rates and room for improvement in product added value. Therefore, it is urgent to develop deep-processed products of white apricots to improve resource utilization and industrial economic benefits.

[0003] Probiotics are active microorganisms that can improve and enhance the balance of the human gut microbiota, playing a positive role in promoting overall human health and physiological mechanisms. Developing nutritious and multifunctional fermented beverages using probiotics and other bio-fermentation technologies can not only effectively extend the shelf life of white apricots but also inhibit the growth of spoilage bacteria, while simultaneously giving the beverage a richer fermented flavor and higher nutritional value. Studies have confirmed that fermenting white apricots with lactic acid bacteria can not only optimize and improve their flavor, producing a unique fruity and fermented aroma, but also enhance the product's antioxidant capacity and has potential probiotic effects such as promoting digestive health and enhancing immunity. Therefore, developing a probiotic plant-based fermented beverage based on white apricots is of great significance in improving the utilization rate of white apricot resources and increasing product added value. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a plant-based fermented beverage made from white apricot probiotics, comprising white apricots, water, and a compound bacterial strain, wherein the compound bacterial strain includes Lactobacillus rhamnosus and Lactobacillus casei.

[0005] This invention also provides a method for preparing the above-mentioned apricot probiotic plant-based fermented beverage, characterized by comprising the following steps:

[0006] (1) Pulping: Put the white apricots and water into a pulping machine to pulp and obtain a white apricot homogenate;

[0007] (2) Sterilization: Sterilize the white apricot homogenate at 80℃ for 15 min;

[0008] (3) Inoculation and fermentation: Cool the sterilized white apricot homogenate to room temperature, inoculate with the compound strain, mix and ferment.

[0009] Furthermore, the ratio of white apricots to water in step (1) is 1:2 by volume.

[0010] Furthermore, the inoculation amount in step (3) is 10% of the homogenate mass.

[0011] Furthermore, the composite strain mentioned in step (3) includes Lactobacillus rhamnosus and Lactobacillus casei, with a mass ratio of Lactobacillus rhamnosus to Lactobacillus casei of 1:1.

[0012] The present invention has the following beneficial effects:

[0013] 1. Establishment of pretreatment and sensory evaluation methods for white apricots: Determine the ratio of white apricots to drinking water, the physicochemical properties of white apricot probiotic plant-based fermented beverage, and establish sensory evaluation standards for white apricot probiotic plant-based fermented beverage from the perspectives of taste, flavor, and sweetness / sourness.

[0014] 2. Screening and Combination Optimization of Microbial Strains: A plant-based fermented beverage based on white apricot probiotics was screened from six probiotic strains (LR-Lactobacillus rhamnosus, LC-Lactobacillus casei, LP-Lactobacillus plantarum, LF-Lactobacillus fermentatus, L.P95-Lactobacillus plantarum, and L.F04-Lactobacillus fermentatus). Among them, the beverage fermented by LR-Lactobacillus rhamnosus has more flavor substances, while the beverage fermented by LC-Lactobacillus casei has strong oxidizing properties. By combining the two strains, a compound strain fermented beverage with strong oxidizing properties and more flavor substances was obtained.

[0015] 3. Optimization of fermentation process for plant-based fermented beverages containing white apricot probiotics: Using white apricot as the base material, the base formula of the plant-based fermented beverage containing white apricot probiotics was optimized. Secondly, using compound strains as fermentation agents, orthogonal technology was used to optimize fermentation process parameters (fermentation time, temperature, inoculum amount) to develop processing technology for plant-based fermented beverages containing white apricot probiotics. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 Schematic diagram of electronic nose assay for different bacterial strains during fermentation;

[0018] Figure 2 pH value determination during fermentation by different bacterial strains;

[0019] Figure 3 Determination of DP and pH values ​​during fermentation by different bacterial strains;

[0020] Figure 4 Determination of FRAP values ​​for fermentation by different bacterial strains;

[0021] Figure 5 Schematic diagram of the effect of the ratio of white apricots to drinking water on the sensory quality of beverages;

[0022] Figure 6 Schematic diagram showing the effect of bacterial inoculation on the sensory quality of beverages;

[0023] Figure 7 Schematic diagram illustrating the effect of fermentation temperature on the sensory quality of beverages;

[0024] Figure 8 Schematic diagram illustrating the effect of fermentation time on the sensory quality of beverages;

[0025] Figure 9 Schematic diagram of electronic nose assay after fermentation of single and compound strains. Detailed Implementation

[0026] Various exemplary embodiments of the present invention are now described in detail. Unless otherwise specified, the methods used in the embodiments are conventional methods, and the reagents used are commercially available reagents or reagents prepared using conventional methods. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0027] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0028] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0029] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0030] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0031] Please see Figures 1 to 9 The present invention provides a technical solution:

[0032] Example 1: Preparation process of a plant-based fermented beverage containing white apricot probiotics

[0033] The white apricots are produced in the Xinjiang Uygur Autonomous Region. When purchasing, they are round and plump, with a regular shape, delicate and tender flesh, and a soft and glutinous texture, indicating high overall quality. Furthermore, the white apricots show no signs of pest damage or disease.

[0034] The preparation process of the white apricot probiotic plant-based fermented beverage is as follows: Wash and drain fresh white apricots → cut into pieces → pulp → sterilize → inoculate and ferment → finished product.

[0035] Pulping: Mix the sliced ​​white apricots and drinking water in the correct proportions and put them into a pulping machine for 5 minutes to ensure even pulping;

[0036] Sterilization: The well-mixed fermented white apricot broth was sterilized at 80℃ for 15 minutes;

[0037] Inoculation and fermentation: After the sterilized apricot fermentation broth is cooled to room temperature, activated Lactobacillus rhamnosus and Lactobacillus casei are inoculated at a volume ratio of 1:1. After adding the two bacteria, they are mixed and fermented.

[0038] Example 2: Determination of Fermentation Process

[0039] 1) Screening and combination optimization of strains: A plant-based fermented beverage of white apricot probiotics was screened from 6 probiotic strains (LR-Lactobacillus rhamnosus, LC-Lactobacillus casei, LP-Lactobacillus plantarum, LF-Lactobacillus fermentatus, L.P95-Lactobacillus plantarum, L.F04-Lactobacillus fermentatus). Among them, the beverage fermented by LC-Lactobacillus casei has strong oxidizing properties, while the beverage fermented by LR-Lactobacillus rhamnosus has more flavor substances. After combining the two strains, a compound strain with strong oxidizing properties and more flavor substances was obtained.

[0040] 2) Using the ratio of white apricots to drinking water (1:1, 1:2, 1:3, 1:4, 1:5), inoculum size (8%, 9%, 10%, 11%, 12%), fermentation time (4 h, 6 h, 8 h, 10 h, 12 h), and fermentation temperature (36 ℃, 37 ℃, 38 ℃, 39 ℃, 40 ℃) as factors to be investigated, and sensory evaluation as the evaluation index, single-factor experiments were conducted to determine the optimal fermentation conditions.

[0041] Example 3: Establishment of Sensory Evaluation

[0042] The sensory evaluation method for the Xiaobaixing probiotic plant-based fermented beverage was based on GB19302-2010 National Food Safety Standard for Fermented Milk, with slight modifications. A professional evaluation panel of 20 people, consisting of 10 males and 10 females, was randomly selected to conduct sensory evaluations of the taste, flavor, sweetness and sourness, and color of the prepared Xiaobaixing probiotic plant-based fermented beverage. The sensory scores were collected, statistically analyzed, and the data were collected. The sensory evaluation criteria for the Xiaobaixing probiotic plant-based fermented beverage are shown in Table 1.

[0043] Example 4 Determination of antioxidant properties

[0044] 1) Determination of DPPH free radical scavenging rate:

[0045] Mix 1 ml of methanol with 4 ml of DPPH-methanol solution (0.1 mmol / L) and place in the dark for 30 min. Measure the absorbance value A0 at 517 nm. Mix 1 ml of sample solution with 4 ml of DPPH-methanol solution (0.1 mmol / L) and place in the dark for 30 min. Measure the absorbance value Ai at 517 nm.

[0046]

[0047] 2) FRAP antioxidant assay:

[0048] The total antioxidant capacity of the reaction system was determined by referring to the Rumpf FRAP method and modified accordingly, and the T-AOC kit was used in accordance with the instructions.

[0049] Example 5 Flavor Analysis

[0050] Electronic nose assay: Add 5 ml of sample solution to a 20 ml sample vial, tighten the cap, and let stand for 30 minutes. Detection procedure: Preparation time 5 s, cleaning time 60 s, sample injection and detection time 120 s.

[0051]

[0052] Results Analysis

[0053] 1. Screening of strains

[0054] The electronic nose needs to demonstrate good differentiation ability among fermented apricot juice samples through different sensors. For example... Figure 1As shown, throughout the test, the response values ​​of sensors R2, R6, and R9 were significantly higher than those of other sensors. Among them, R2 had the highest response value. Sensor R2 showed outstanding response values ​​in LR and LC fermentation. After the addition of lactic acid bacteria, the sensor response type remained unchanged, but the response values ​​were significantly different (p < 0.05). LR and LC fermentation resulted in a white apricot juice with more milky, caramel, floral, and aromatic flavors.

[0055] pH is the simplest and most accurate indicator for evaluating the sensory properties of fermented white apricot juice. For example... Figure 2 As shown, after 20 hours of fermentation, the pH values ​​of CK, LR, LC, LF, LP, LP, L.F04, and LP 95 were 4.81, 4.10, 4.30, 4.23, 4.04, 4.15, and 4.02, respectively, with LR and LC showing the most significant pH changes. During fermentation, lactic acid bacteria absorb polysaccharides from white apricots, producing lactic acid and other organic acids. This leads to a decrease in pH and an increase in acidity. The significant pH changes suggest that LR and LC may be more suitable for growth in white apricot juice.

[0056] Antioxidant capacity is a key attribute closely related to potential health-promoting properties and consumer appeal. DPPH is a commonly used method for measuring antioxidant capacity. The addition of lactic acid bacteria to fermented pear juice increased its DPPH free radical scavenging activity. The DPPH free radical scavenging activities of LR, LC, LF, LP, LP, L.F04, and LP 95 were 64.40%, 69.02%, 62.69%, 65.11%, 63.36%, and 65.13%, respectively. Compared with the control (CK), these activities increased by 3.55%, 8.17%, 1.84%, 4.26%, 2.52%, and 4.28%, respectively. Among them, LR, LC, LP, L.F04, and LP 95 showed the most significant increases in antioxidant capacity after fermentation of white apricot juice.

[0057] In conclusion, LR and LC are the most suitable bacterial strains for fermenting white apricot juice. Further experiments were conducted using a 1:1 mixed culture of these strains.

[0058] 2. Process optimization

[0059] like Figure 5 As shown, the highest score (p<0.05) was 89.20±1.11 when the material-to-liquid ratio was 1:2. The fermented apricot juice had a balanced sweet and sour taste, rich and full-bodied, with not only the delicate aroma of apricots but also the flavor of fermentation. The sensory score initially increased and then decreased with increasing component ratios, possibly because the increased water content diluted the flavor; adding too much water weakened the apricot aroma, while reducing the water content might make the juice too thick. Orthogonal experiments were conducted using ratios of 1:1, 1:2, and 1:3.

[0060] like Figure 6 As shown, when the inoculum concentration was between 8% and 10%, the sensory score significantly improved (p < 0.05), increasing from 83.30±0.52 to 91.10±1.01. The highest sensory score was achieved at an inoculum concentration of 10% (p < 0.05). At this concentration, the product had a good taste, with a balanced acidity and sweetness, and a rich and refreshing fruity aroma accompanied by fermentation notes. If the inoculum concentration was too low, the product would have a slightly sour taste, potentially leading to a sweeter flavor; if the inoculum concentration was too high, the product would be overly sour and lack the aroma of lactic acid. Orthogonal experiments were conducted using inoculum concentrations of 9%, 10%, and 11%.

[0061] Figure 7 The fermentation temperature was between 36 °C and 38 °C. The juice achieved a high sensory score (p<0.05). The highest score reached 88.07±1.10 when the fermentation temperature gradually increased to 37 °C. As the fermentation temperature continued to rise, the sensory score decreased (p<0.05). This indicates that if the temperature is too low, the activity of lactic acid bacteria will weaken, thus inhibiting lactic acid fermentation. However, if the temperature is too high, it may lead to the loss of flavor and nutrients, thus affecting the quality of the fermented apricot juice. Finally, orthogonal experiments were conducted to select 36 °C, 37 °C, and 38 °C.

[0062] like Figure 8 As shown, the sensory score initially increased and then decreased with fermentation time, reaching its highest score (87.13 ± 0.71) after 8 hours of fermentation. If the fermentation time is too short, sufficient flavor cannot be produced in the apricot juice. If the fermentation time is too long, the juice becomes overly acidic, significantly affecting sensory evaluation and making the taste excessively sour and astringent. Therefore, fermentation time of 4 to 12 hours not only saves fermentation time but also achieves ideal texture, flavor, and taste. In the orthogonal test, three levels were used: 6 hours, 8 hours, and 10 hours. The inoculum size affected the growth and reproduction rate of lactic acid bacteria in the beverage, as well as their ability to break down macromolecules and produce acid.

[0063] As shown in Table 3, the factors affecting sensory quality are: A>C>D>B. The material-to-liquid ratio, inoculum size, fermentation temperature, and fermentation time have a highly significant impact on the quality of the white apricot probiotics (p<0.001). Table 4 shows that the optimal fermentation combination is A2B2C3D1, with a material-to-liquid ratio of 1:2, an inoculum size of 9%, a fermentation temperature of 38°C, and a fermentation time of 6 h. Since the optimal ratio A2B2C2D2 is not present in the orthogonal experiment, further experimental verification is needed to determine its reliability. It has been confirmed that with a material-to-liquid ratio of 1:2, an inoculum size of 10%, a fermentation temperature of 37 ℃, and a fermentation time of 8 h, the sensory score is 90.20±1.06, higher than that of the orthogonal experiment. Therefore, the optimal production process is: a material-to-liquid ratio of 1:2, an inoculum size of 10%, a fermentation temperature of 37 ℃, and a fermentation time of 8 h.

[0064] 3. Physicochemical properties

[0065] Electronic nose detection is widely used in fermented foods and beverages, serving as an important physicochemical indicator for assessing the quality and flavor of fermented products. Through strain screening and process optimization, single and mixed fermentation (LC:LR = 1:1) of LC and LR were used to obtain a fermented beverage of white apricot probiotics, such as... Figure 9 It can be seen that by adding lactic acid bacteria for fermentation, the product's response values ​​R2, R6, and R9 are higher than other response values. Among them, the R9 of mixed fermentation is the highest, and R9 is significantly affected by aromatic compounds, corresponding to floral and fruity aromas. This indicates that the floral and fruity aromas are rich after mixed fermentation. Next is R6, which is significantly affected by methane and short-chain alkanes, corresponding to fatty and milky aromas. Meanwhile, the R2 response value is significantly affected by nitrogen oxides, exhibiting caramel and roasted aromas. The R2 response value of mixed fermentation is not significantly different from that of single-strain fermentation. Finally, mixed strain fermentation was selected to produce the white apricot probiotic fermented beverage.

[0066] 4. Conclusion

[0067] This study indicates that white apricot is a suitable fermentation mechanism for both LC and LR fermentation, and investigated the effects of single-lactic acid bacteria fermentation and mixed-lactic acid bacteria fermentation. The results showed that lactic acid bacteria fermentation significantly affected the flavor and physiological activity of the white apricot probiotic fermented beverage. The fermentation process enhanced the antioxidant capacity of the pear juice. Gas chromatography-ion mobility spectrometry and electronic nose analysis revealed significant changes in the flavor of Korla pear juice after lactic acid bacteria fermentation. Electronic nose results showed that the white apricot probiotic fermented beverage exhibited a rich caramel, milk, and fruity aroma after LC and LR mixed fermentation.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A plant-based fermented beverage containing white apricot probiotics, characterized in that, The components include white apricot, water, and a complex strain of bacteria, which includes Lactobacillus rhamnosus and Lactobacillus casei.

2. The preparation method of the apricot probiotic plant-based fermented beverage as described in claim 1, characterized in that, Includes the following steps: (1) Pulping: Put the white apricots and water into a pulping machine to pulp and obtain a white apricot homogenate; (2) Sterilization: Sterilize the white apricot homogenate at 80℃ for 15 min; (3) Inoculation and fermentation: Cool the sterilized white apricot homogenate to room temperature, inoculate with the compound strain, mix and ferment.

3. The preparation method according to claim 2, characterized in that, The ratio of white apricots to water in step (1) is 1:2 by volume.

4. The preparation method according to claim 2, characterized in that, The inoculation amount mentioned in step (3) is 8% of the homogenate mass.

5. The preparation method according to claim 2, characterized in that, The composite strain mentioned in step (3) includes Lactobacillus rhamnosus and Lactobacillus casei, with a mass ratio of Lactobacillus rhamnosus to Lactobacillus casei of 1:1.

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