Fermented fruit and vegetable compound slurry and preparation method thereof

Abstract

The application discloses a kind of fruit and vegetable compound fermentation original pulp and preparation method thereof, belong to the technical field of beverage.The fruit and vegetable compound fermentation original pulp prepared by the preparation method provided in the application, macromolecule in fruit and vegetable is degraded thoroughly, nutrition is released more fully, the fruit and vegetable compound fermentation original pulp prepared is completely utilized pure fruit and vegetable natural juice, does not need additional pure water, i.e.high concentration fruit and vegetable compound fermentation original pulp is obtained;The fruit and vegetable compound fermentation original pulp prepared is rich in flavor, high in nutritional density, mild and stable in nature, smooth and warm in taste;Can effectively retain the nourishing activity of fruit and vegetable and ginseng, medlar and yam, have the effects of antioxidation, conditioning and tonifying, mild and health care, suitable for long-term nursing drinking demand;The preparation method provided can effectively avoid the pollution of pathogenic bacteria, harmful bacteria and fungi, the condition is mild, the requirement for instrument and equipment is low, the process is stable and can be standardized, suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of beverage technology, and in particular to a fruit and vegetable compound fermented pulp and its preparation method. Background Technology

[0002] Fruit and vegetable juice drinks are broadly categorized into fruit juice, vegetable juice, and compound fruit and vegetable juice. Fruit juice is made from fresh or refrigerated fruits through physical methods such as pressing and extraction; it is a juice that is fermentable but not fermented. Alternatively, it may be made by extracting juice from fruits using percolation or extraction processes and then removing added solvents using physical methods. Another option is to add an equal amount of water to concentrated fruit juice to retain the original fruit pulp's color, flavor, and soluble solids content. Vegetable juice is made by mechanically processing vegetables to obtain juice, which is then mixed with water, salt, sugar, etc. Compound fruit and vegetable juice drinks are products made by mixing fruit and vegetable juices in a certain proportion and then adding sugar, etc. National standards stipulate that only products containing 100% fruit or vegetable juice can be called fruit and vegetable juice; all others must be labeled as fruit and vegetable juice beverages.

[0003] Unfermented fruit and vegetable juices are highly susceptible to oxidation and spoilage. Upon contact with air, they quickly change color, lose flavor, and the pulp tends to separate and settle, severely impacting their appearance. Furthermore, due to their high content of virgin fruit acids, they are bitter, astringent, and have a strong raw taste, making them unpalatable. Drinking them on an empty stomach can easily irritate the stomach and cause acid reflux. Additionally, to neutralize the virgin fruit acids, a large amount of sugar is added, which is detrimental to health and unfriendly to those trying to control their blood sugar levels.

[0004] Fermented fruit and vegetable juices are beverages made from fruits or vegetables (or their juice) through controlled fermentation by beneficial microorganisms such as lactic acid bacteria and yeast. They typically contain active probiotics, organic acids, B vitamins, and a small amount of ethanol, offering both natural flavor and potential for gut health. However, fermented fruit and vegetable juices face the challenge of controlling process parameters. Without the addition of flavorings, stabilizers, nutritional supplements, or other chemical additives, they are highly susceptible to problems such as severe nutrient loss, weak fruit flavor, even rancidity, loss of original color, browning, a "sour but not fragrant, sweet but not smooth" taste, and poor stability (fruit pulp, protein, and polysaccharides easily precipitate). Summary of the Invention

[0005] The purpose of this invention is to provide a fruit and vegetable compound fermentation pulp and its preparation method, in order to solve the problems of low juice yield, need for additional pure water, slow fermentation start-up, incomplete conversion, rough taste, sour aftertaste, low nutritional value, poor appearance and stability, easy stratification and sedimentation in existing fruit and vegetable juice fermentation technology.

[0006] To achieve the above objectives, the present invention provides a method for preparing fruit and vegetable compound fermentation pulp, comprising the following steps: S1. After washing and crushing all raw materials, then homogenize them into a paste; S2. Add fructooligosaccharides to the homogenate obtained in S1, mix well, and then enzymatically hydrolyze. S3. After the enzymatic hydrolysis of S2 is completed, the enzyme inactivation and sterilization of the system are carried out. After the system is cooled to 30~35℃, inoculation and fermentation are carried out. S4. After the fermentation of S3 is completed, filter the system and take the filtrate for a second fermentation. After fermentation in S5 and S4 is completed, the fruit and vegetable compound fermented pulp is obtained by fine filtration and clarification.

[0007] Preferably, the raw materials in S1 include pineapple, apple, kiwi, goji berries, red dates, blueberries, cherries, lemons, ginseng, and yam; ginseng and goji berries are mixed and crushed, then ground into powder and passed through a 40-60 sieve; apples and cherries are the pulp after removing the pits, kiwis are the pulp after peeling, yam is fresh yam after removing the outer skin, and red dates are the dried pulp after removing the pits.

[0008] Preferably, the weight ratio of pineapple, apple, kiwi, goji berry, red date, blueberry, cherry, lemon, ginseng and yam is 6:7~8:4~5:2~3:3:2:2~3:1~1~2:1:2~3.

[0009] Preferably, the weight ratio of pineapple, apple, kiwi, goji berry, red date, blueberry, cherry, lemon, ginseng, and yam is 6:7.5:4.5:2.5:3:2:2.5:1~1.5:1:2.5.

[0010] Preferably, in step S1, the homogenate is treated with ultrasonic waves at 20-25 kHz for 30-40 minutes; in step S2, the amount of fructooligosaccharides added is 5-7% of the total mass of the raw materials in step S1; and enzymatic hydrolysis is carried out using pectinase and cellulase.

[0011] Preferably, in step S3, enzyme inactivation and sterilization are performed by incubation at 80-90℃ for 10-20 minutes; inoculation is carried out by inoculating with a compound fermentation powder, which is composed of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a live bacteria ratio of 1:1:1, and the total live bacteria count of the compound fermentation powder inoculation is 1.2 × 10⁻⁶. 7 ~1.2×10 9 CFU / g of total raw material mass.

[0012] Preferably, the fermentation in S3 is carried out under sealed conditions at 24~28℃ for 300~360 days.

[0013] Preferably, the filtration in S4 adopts a pressing filtration method, and the pressing filtration conditions are: pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with a 60-mesh food-grade nylon filter screen, and aseptic closed operation throughout the process; the conditions for the second fermentation are static fermentation at 20~25℃ for 100~200 days.

[0014] Preferably, a plate and frame filter press is used for coarse and fine filtration with 200-mesh polypropylene filter cloth, followed by a series ultrafiltration membrane with a molecular weight cutoff of 8000 Da for room temperature circulation fine filtration, with the filtration temperature controlled at 18~22℃; the specific method for clarification treatment is to let it stand at low temperature in a sterile sealed container at 10~14℃ for 48 hours to separate the layers, and then siphon off the upper clear liquid without adding any external clarification aids.

[0015] The fruit and vegetable compound fermentation pulp prepared by the method described above.

[0016] Therefore, the specific technical effects of the fruit and vegetable compound fermentation pulp and its preparation method provided by the present invention are as follows: (1) This invention provides a novel method for preparing fruit and vegetable compound fermented pulp. Through low-temperature enzymatic hydrolysis, ultrasonic cell disruption, ultra-long-cycle two-stage deep fermentation and secondary chelation aging, the prepared beverage utilizes the natural juice of pure fruits and vegetables without the need to add pure water, thus obtaining a high-concentration fruit and vegetable compound fermented pulp. (2) The preparation method provided by this invention completely degrades macromolecules and releases nutrients more fully. Through pectin and crude fiber, the acid and astringent stimulation is removed. Combined with yam to neutralize fruit acid, the taste is mild and smooth. The prepared fruit and vegetable compound fermented pulp has a rich and mellow flavor, high nutrient density, mild and stable properties (no layering, precipitation or browning phenomenon was observed after standing at room temperature for 180 days), and a smooth and mild taste. It can effectively retain the nourishing activity of fruits and vegetables, ginseng, wolfberry and yam, and has the effects of anti-oxidation, conditioning and nourishing, and mild health care, which is suitable for long-term conditioning drinking needs. (3) The preparation method provided by the present invention can effectively avoid contamination by pathogenic bacteria, harmful bacteria and fungi. The conditions are mild, the requirements for instruments and equipment are low, the process is stable and can be standardized, and it is suitable for industrial production.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention 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.

[0019] Figure 1 This is a photo of the fruit and vegetable compound fermented pulp prepared in Example 1 of this invention after it has been packaged. Figure 2 This is a photograph of the fruit and vegetable compound fermentation pulp prepared in Example 1 of the present invention poured into a transparent beaker. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] To make the objectives, technical solutions, and advantages of this application clearer, more thorough, and more complete, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The following detailed descriptions are all illustrations of embodiments, intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] The instruments, equipment, reagents and materials used in the embodiments were all obtained through commercial means; the methods and steps not described in detail in the embodiments are all conventional techniques in the art.

[0023] Example 1 The specific steps for preparing a fruit and vegetable compound fermented pulp are as follows: S1. Rinse 20g of ginseng (3-year-old garden ginseng slices) and 50g of wolfberry with running drinking water to remove surface dust, then crush them and pass them through a 60-mesh sieve.

[0024] S2. After washing the other raw materials, weigh out 120g of pineapple, 150g of Fuji apples (after removing the core), 90g of red kiwifruit (after peeling the flesh), 60g of dried red dates (after removing the core), 40g of fresh blueberries, 50g of fresh cherry flesh after removing the core, 25g of lemon (with peel), and 50g of fresh peeled yam. Grind them together, add the powder sieved in step S1, stir and mix well, and then use an ultrasonic blender to make a pulp (25kHz, ultrasonic treatment for 40min).

[0025] S3. Add 40g of oligofructose to the mixture after pulping in step S2, stir and mix well, then add 0.15g of pectinase (enzyme activity of 10,000 U) and 0.2g of cellulase (enzyme activity of 10,000 U), and enzymatically hydrolyze for 100min at 45℃ and 180rpm.

[0026] S4. After the enzymatic hydrolysis in step S3 is completed, heat the system to 85℃ and keep it at that temperature for 15 minutes. Then, allow it to cool naturally to 31±2℃ before inoculating it with a compound fermentation starter culture (composed of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a live bacteria ratio of 1:1:1, with a total live bacteria count of 1.2×10⁻⁶). 7After stirring and mixing, ferment at a sealed constant temperature of 24±2℃ for 360 days. After fermentation, press and filter under aseptic conditions (pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with 60-mesh food-grade nylon filter, and aseptic and sealed operation throughout the process) to remove fruit residue and obtain fermented clear pulp.

[0027] S5. Place the fermented slurry obtained in step S4 into a sealed container and let it ferment at 22±2℃ for 180 days. Then, use a plate and frame filter press with a 200-mesh polypropylene filter cloth for coarse and fine filtration, followed by a series ultrafiltration membrane with a molecular weight cutoff of 8000 Da for room temperature circulation fine filtration, with the filtration temperature controlled at 18~22℃. After fine filtration, let it stand at 10~14℃ in a sterile sealed container for 48 hours to separate the layers. Siphon off the upper clear liquid (without adding exogenous clarifying agents) to obtain the fruit and vegetable compound fermented slurry. A photo of the bottled fruit and vegetable compound fermented slurry is shown below. Figure 1 The photo shown shows the fruit and vegetable fermented slurry poured into a transparent beaker. Figure 2 As shown.

[0028] Example 2 The specific steps for preparing a fruit and vegetable compound fermented pulp are as follows: S1. Rinse 20g of ginseng (3-year-old garden ginseng slices) and 50g of wolfberry with running drinking water to remove surface dust, then crush them and pass them through a 60-mesh sieve.

[0029] S2. After washing the other raw materials, weigh out 120g of pineapple, 150g of Qin Guan apple (after removing the core), 90g of green kiwi (after peeling the flesh), 60g of dried red dates (after removing the core), 40g of fresh blueberries, 50g of fresh cherry flesh after removing the core, 25g of lemon (with peel), and 50g of fresh peeled yam. Grind them into a paste, add the powder sieved in step S1, stir and mix well, and then use an ultrasonic blender to make a paste (20kHz, ultrasonic treatment for 30min).

[0030] S3. Add 40g of fructooligosaccharide to the mixture after pulping in step S2, stir and mix well, then add 0.15g of pectinase (enzyme activity of 10,000 U) and 0.2g of cellulase (enzyme activity of 10,000 U), and enzymatically hydrolyze for 90min at 45℃ and 180rpm.

[0031] S4. After the enzymatic hydrolysis in step S3 is completed, heat the system to 85℃ and keep it at that temperature for 15 minutes. Then, allow it to cool naturally to 31±2℃ before inoculating it with a compound fermentation starter culture (composed of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a live bacteria ratio of 1:1:1, with a total live bacteria count of 1.2×10⁻⁶). 7After stirring and mixing, ferment at a sealed constant temperature of 24±2℃ for 360 days. After fermentation, press and filter under aseptic conditions (pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with 60-mesh food-grade nylon filter, and aseptic and sealed operation throughout the process) to remove fruit residue and obtain fermented clear pulp.

[0032] S5. Place the fermented slurry obtained in step S4 into a sealed container and let it ferment at 22±2℃ for 180 days. Then, use a plate and frame filter press with a 200-mesh polypropylene filter cloth for coarse and fine filtration, followed by a series ultrafiltration membrane with a molecular weight cutoff of 8000 Da for room temperature circulation fine filtration, with the filtration temperature controlled at 18~22℃. After fine filtration, let it stand at a sterile sealed container at 10~14℃ for 48 hours to separate the layers. Siphon off the upper clear liquid (without adding exogenous clarifying agents) to obtain the fruit and vegetable compound fermented slurry.

[0033] Example 3 The specific steps for preparing a fruit and vegetable compound fermented pulp are as follows: S1. Rinse 20g of ginseng (3-year-old garden ginseng slices) and 50g of wolfberry with running drinking water to remove surface dust, then crush them and pass them through a 60-mesh sieve.

[0034] S2. After washing the other raw materials, weigh out 120g of pineapple, 150g of Red Delicious apple (after removing the core), 90g of red kiwi (after peeling the flesh), 60g of dried red dates (after removing the core), 40g of fresh blueberries, 50g of fresh cherry flesh (after removing the core), 25g of lemon (after peeling and removing the seeds), and 50g of fresh peeled yam. Grind them together, add the powder sieved in step S1, stir and mix well, and then use an ultrasonic blender to make a pulp (25kHz, ultrasonic treatment for 40min).

[0035] S3. Add 40g of oligofructose to the mixture after pulping in step S2, stir and mix well, then add 0.15g of pectinase (enzyme activity of 10,000 U) and 0.2g of cellulase (enzyme activity of 10,000 U), and enzymatically hydrolyze for 120min at 45℃ and 180rpm.

[0036] S4. After the enzymatic hydrolysis in step S3 is completed, heat the system to 85℃ and keep it at that temperature for 15 minutes. Then, allow it to cool naturally to 31±2℃ before inoculating it with a compound fermentation starter culture (composed of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a live bacteria ratio of 1:1:1, with a total live bacteria count of 1.2×10⁻⁶). 7 After stirring and mixing, ferment at a sealed constant temperature of 24±2℃ for 360 days. After fermentation, press and filter under aseptic conditions (pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with 60-mesh food-grade nylon filter, and aseptic and sealed operation throughout the process) to remove fruit residue and obtain fermented clear pulp.

[0037] S5. Place the fermented slurry obtained in step S4 into a sealed container and let it ferment at 22±2℃ for 180 days. Then, use a plate and frame filter press with a 200-mesh polypropylene filter cloth for coarse and fine filtration, followed by a series ultrafiltration membrane with a molecular weight cutoff of 8000 Da for room temperature circulation fine filtration, with the filtration temperature controlled at 18~22℃. After fine filtration, let it stand at a sterile sealed container at 10~14℃ for 48 hours to separate the layers. Siphon off the upper clear liquid (without adding exogenous clarifying agents) to obtain the fruit and vegetable compound fermented slurry.

[0038] Example 4 The specific steps for preparing a fruit and vegetable compound fermented pulp are as follows: S1. Rinse 20g of ginseng (3-year-old garden ginseng slices) and 50g of wolfberry with running drinking water to remove surface dust, then crush them and pass them through a 40-mesh sieve.

[0039] S2. After washing the other raw materials, weigh out 120g of pineapple, 150g of Fuji apples (after removing the cores), 90g of red kiwifruit (after peeling the flesh), 60g of dried red dates (after removing the cores), 40g of fresh blueberries, 50g of fresh cherry flesh (after removing the cores), 25g of lemon (after peeling and removing the seeds), and 50g of fresh peeled yam. Grind them together, add the powder sieved in step S1, stir and mix well, and then use an ultrasonic blender to make a pulp (25kHz, ultrasonic treatment for 40min).

[0040] S3. Add 40g of fructooligosaccharide to the mixture after pulping in step S2, stir and mix well, then add 0.15g of pectinase (enzyme activity of 10,000 U) and 0.2g of cellulase (enzyme activity of 10,000 U), and enzymatically hydrolyze for 90min at 50℃ and 200rpm.

[0041] S4. After the enzymatic hydrolysis in step S3 is completed, heat the system to 85℃ and keep it at that temperature for 15 minutes. Then, allow it to cool naturally to 31±2℃ before inoculating it with a compound fermentation starter culture (composed of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a live bacteria ratio of 1:1:1, with a total live bacteria count of 1.2×10⁻⁶). 7 After stirring and mixing, ferment at a sealed constant temperature of 24±2℃ for 360 days. After fermentation, press and filter under aseptic conditions (pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with 60-mesh food-grade nylon filter, and aseptic and sealed operation throughout the process) to remove fruit residue and obtain fermented clear pulp.

[0042] S5. Place the fermented slurry obtained in step S4 into a sealed container and let it ferment at 22±2℃ for 180 days. Then, use a plate and frame filter press with a 200-mesh polypropylene filter cloth for coarse and fine filtration, followed by a series ultrafiltration membrane with a molecular weight cutoff of 8000 Da for room temperature circulation fine filtration, with the filtration temperature controlled at 18~22℃. After fine filtration, let it stand at a sterile sealed container at 10~14℃ for 48 hours to separate the layers. Siphon off the upper clear liquid (without adding exogenous clarifying agents) to obtain the fruit and vegetable compound fermented slurry.

[0043] Comparative Example The specific steps for preparing fruit and vegetable compound fermented pulp using traditional methods are as follows: S1. Raw material pretreatment: Take equal weights of 3-year-old garden ginseng and wolfberry, rinse with clean water to remove dust, then crush with a regular pulverizer and pass through a 60-mesh sieve for later use; weigh pineapple, Fuji apple, red kiwi, dried red dates, blueberries, cherries, lemons, and yam according to the same weight ratio as in the example, wash, pit, peel, and chop manually, mix with ginseng and wolfberry powder, add an equal amount of purified water and simply stir to form a slurry, without using ultrasonic cell wall breaking treatment.

[0044] S2. Preparation process: Pour the mixed slurry into a mixing tank, add white sugar to adjust the sweetness, do not add fructooligosaccharides, pectinase, or cellulase, stir at 180 rpm for 20 minutes at room temperature to mix evenly, without a constant temperature enzymatic hydrolysis step.

[0045] S3. Sterilization and Fermentation Inoculation: The mixture obtained in step S2 is heated to 90℃ and kept at that temperature for 10 minutes for high-temperature sterilization. After naturally cooling to 35℃, only a single type of Lactobacillus acidophilus (total viable count 3×10⁵) is inoculated. 5 The raw material (CFU / g) is fermented at room temperature in an open manner, with a fermentation cycle of 7 days. There is no deep fermentation process of 360 days in a closed constant temperature at 24~28℃.

[0046] S4. Coarse filtration: After fermentation, only four layers of medical gauze are used for natural gravity filtration. High-pressure pressing of 0.25~0.35MPa and pressing and separation with a 60-mesh filter are not used. The filtrate is collected directly after filtration, and the fruit residue is discarded.

[0047] S5. Post-processing: The filtrate does not undergo secondary aging and fermentation, plate and frame filter + ultrafiltration membrane fine filtration, low-temperature static clarification steps, or layer purification. The filtrate is simply cooled to room temperature to directly obtain the traditional process fruit and vegetable compound fermentation pulp.

[0048] Effect test (1) The fruit and vegetable compound fermented pulp prepared in Example 1 was sent to a third-party testing institution for testing. The testing items included: soluble solids, total acid, pH value, total polyphenols, total flavonoids, amino acid nitrogen, dietary fiber, total bacterial count, coliform bacteria, mold, yeast, and pathogenic bacteria (including Salmonella and Staphylococcus aureus). The national standard information for the testing is as follows: Soluble solids: GB / T 12143-2008 "General Analytical Methods for Beverages"; Total acidity: GB / T 12456-2021 "Determination of total acidity in food"; pH value: GB 5009.237-2016 "National Food Safety Standard - Determination of pH Value in Food"; Total polyphenols: GB / T 31740.2-2015 "Test Procedures for Physicochemical and Hygienic Indicators of Health Foods Part 2: Polyphenolic Substances"; Total flavonoids: GB / T 31740.2-2015 "Test Procedures for Physicochemical and Hygienic Indicators of Health Foods Part 2: Flavonoids"; Amino acid nitrogen: GB 5009.124-2016 "National Food Safety Standard - Determination of Amino Acids in Food"; Dietary fiber: GB 5009.88-2014 "National Food Safety Standard - Determination of Dietary Fiber in Food"; Total bacterial count: GB 4789.2-2022 "National Food Safety Standard - Microbiological Examination of Food - Determination of Total Bacterial Count"; Coliform bacteria: GB 4789.3-2022 "National Food Safety Standard - Microbiological Examination of Food - Coliform Count"; Molds and yeasts: GB 4789.15-2016 "National Food Safety Standard - Microbiological Examination of Food: Counting of Molds and Yeasts"; Salmonella: GB 4789.4-2020 National Food Safety Standard - Microbiological Examination of Food - Examination of Salmonella; Staphylococcus aureus: GB 4789.10-2016 "National Food Safety Standard - Microbiological Examination of Food - Examination of Staphylococcus aureus". The results are shown in Table 1.

[0049] Table 1 Test Results

[0050] (2) To investigate the storage stability of the fruit and vegetable compound fermentation pulp prepared in Example 1 and the comparative example.

[0051] The fruit and vegetable fermented slurry prepared in Example 1 and the comparative example were both left to stand at room temperature for 180 days, and were designated as the experimental group and the control group, respectively. The results are as follows: Figure 1 As shown, after standing at room temperature for 180 days, the fruit and vegetable compound fermentation pulp prepared in Example 1 did not exhibit stratification, precipitation, bottle swelling, or browning. In the control group, flocculent precipitate began to appear after 30 days of standing, and significant stratification was observed after 90 days.

[0052] (3) Recruit volunteers to conduct evaluations.

[0053] A total of 120 volunteers were recruited, all in good health, half male and half female, aged 18-65 years, and randomly divided into two groups of 60 each, with volunteers in the same or similar age range. One group of volunteers drank the fruit and vegetable compound fermented slurry prepared in Example 1 of this invention, and was designated as the experimental group; the remaining group of volunteers drank the fruit and vegetable compound fermented slurry prepared in the comparative example, and was designated as the control group.

[0054] Both the experimental and control groups of volunteers consumed 20 mL of the corresponding fruit and vegetable compound fermented pulp daily for 30 days. During the experiment, indicators such as taste acceptance, gastrointestinal comfort, mental state, and skin condition were recorded. The results are as follows: ① Taste acceptance: In the experimental group, 96.7% (58 people) of the volunteers found the taste to be sweet and sour, mild, without any astringency or irritation, and smooth and mellow. In the control group, 68.3% (41 people) of the volunteers reported that the taste was sour, astringent, irritating to the throat, had a strong medicinal taste, and was rough.

[0055] ② Gastrointestinal comfort: In the experimental group, 93.3% (56 people) of the volunteers reported that the stomach was soothed, with no bloating or acid reflux, and bowel movements became more regular. In the control group, 55.0% (33 people) of the volunteers reported mild acid reflux, bloating, or gastrointestinal irritation.

[0056] ③ Improvement in mental state and condition: In the experimental group, 88.3% (53 people) of volunteers reported reduced fatigue, improved complexion, and more restful sleep. In the control group, 41.7% (25 people) of volunteers reported slight improvements.

[0057] The above results show that the fruit and vegetable compound fermented pulp prepared by the preparation method provided by the present invention has a better taste, is gentler on the stomach and intestines, has better nutrient absorption, and is more stable. The preparation method provided by the present invention is significantly better than the traditional process.

[0058] Therefore, the fruit and vegetable compound fermented pulp prepared by the method provided by this invention has a more complete degradation of macromolecules in fruits and vegetables, resulting in more sufficient nutrient release. The prepared fruit and vegetable compound fermented pulp utilizes the natural juice of pure fruits and vegetables without the need for additional pure water, thus obtaining a high-concentration fruit and vegetable compound fermented pulp. The prepared fruit and vegetable compound fermented pulp has a rich and mellow flavor, high nutrient density, mild and stable properties, and a smooth and mellow taste. It can effectively retain the nourishing activity of fruits and vegetables, as well as ginseng, wolfberry, and yam, and has antioxidant, conditioning and nourishing, and mild health-preserving effects, making it suitable for long-term health maintenance. The provided preparation method can effectively avoid contamination by pathogenic bacteria, harmful bacteria, and fungi, with mild conditions, low requirements for equipment, stable and standardized processes, and is suitable for industrial production.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a fruit and vegetable compound fermentation pulp, characterized in that, The steps are as follows: S1. After washing and crushing all raw materials, then homogenize them into a paste; S2. Add fructooligosaccharides to the homogenate obtained in S1, mix well, and then enzymatically hydrolyze. S3. After the enzymatic hydrolysis of S2 is completed, the enzyme inactivation and sterilization of the system are carried out. After the system is cooled to 30~35℃, inoculation and fermentation are carried out. S4. After the fermentation of S3 is completed, filter the system and take the filtrate for a second fermentation. After fermentation in S5 and S4 is completed, the fruit and vegetable compound fermented pulp is obtained by fine filtration and clarification.

2. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that: The raw materials in S1 include pineapple, apple, kiwi, goji berries, red dates, blueberries, cherries, lemons, ginseng, and yam; ginseng and goji berries are mixed and crushed, then ground into powder and passed through a 40-60 mesh sieve; apples and cherries are the pulp after removing the pits, kiwis are the pulp after removing the peel, yam is the fresh yam after removing the outer skin, and red dates are the dried pulp after removing the pits.

3. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 2, characterized in that: The weight ratio of pineapple, apple, kiwi, goji berry, red date, blueberry, cherry, lemon, ginseng, and yam is 6:7~8:4~5:2~3:3:2:2~3:1~1~2:1:2~3.

4. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 2, characterized in that: The weight ratio of pineapple, apple, kiwi, goji berry, red date, blueberry, cherry, lemon, ginseng, and yam is 6:7.5:4.5:2.5:3:2:2.5:1~1.5:1:2.

5.

5. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that: In S1, the homogenate is treated with ultrasound at 20-25 kHz for 30-40 minutes; in S2, the amount of fructooligosaccharides added is 5-7% of the total mass of the raw materials in S1; enzymatic hydrolysis is carried out using pectinase and cellulase.

6. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that: In step S3, enzyme inactivation and sterilization are performed by incubation at 80-90℃ for 10-20 minutes. Inoculation involves using a compound fermentation powder, which is a mixture of *Lactobacillus plantarum*, *Bifidobacterium longum* subsp. *longum*, and *Lactobacillus acidophilus* in a 1:1:1 live bacteria ratio. The total live bacteria count in the compound fermentation powder inoculation is 1.2 × 10⁻⁶. 7 ~1.2×10 9 CFU / g of total raw material mass.

7. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that: The fermentation in S3 is carried out under sealed conditions at 24~28℃ for 300~360 days.

8. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that, The filtration in S4 adopts a pressing filtration method. The pressing filtration conditions are: pressing pressure 0.25~0.35MPa, pressing time 18~22min, equipped with a 60-mesh food-grade nylon filter screen, and aseptic closed operation throughout the process; the conditions for the second fermentation are static fermentation at 20~25℃ for 100~200 days.

9. The method for preparing a fruit and vegetable compound fermentation pulp according to claim 1, characterized in that: The specific method for fine filtration in S4 is to use a plate and frame filter press with 200-mesh polypropylene filter cloth for coarse and fine filtration, followed by cyclic fine filtration with an 8000 Da molecular weight cutoff ultrafiltration membrane in series at room temperature, with the filtration temperature controlled at 18~22℃; the specific method for clarification treatment is to let the liquid stand at a sterile sealed container at 10~14℃ for 48 hours to separate into layers, and then siphon off the upper clarified liquid without adding any external clarification aids.

10. The fruit and vegetable compound fermentation pulp prepared by the preparation method described in claims 1 to 9.

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