An enzyme-based black apple and its production process

Abstract

This invention provides an enzyme-based black apple and its production process, belonging to the field of food processing technology. The production process includes: raw material pretreatment, preparation of fermentation broth, inoculation, primary fermentation, secondary fermentation, maturation fermentation, sterilization, packaging, and testing. The resulting enzyme-based black apple has a soluble pectin content ≥179.62 mg / g fresh weight, a protopectin content ≥60.32 mg / g fresh weight, a total phenol content ≥10.05 mg / g, and a total flavonoid content ≥9.84 mg / g. This production process is significantly different from that of candied fruit products, as no exogenous substances are added except for the fermentation probiotic strains. The nutritional value of the final product is also significantly superior to traditional apple candied fruit and fresh fruit products. This invention is of great significance for enriching the variety of deep-processed apple products, promoting the development of the fruit industry, and extending the fruit industry chain.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to an enzyme-based black apple and its production process. Background Technology

[0002] Ripe apples have a sweet and sour taste and are rich in nutrients, containing various bioactive substances such as polysaccharides, dietary fiber, protein, vitamin B1, vitamin B2, and vitamin C. They offer benefits such as lowering cholesterol and blood pressure, promoting bowel movements, and boosting metabolism. Therefore, increasing the processing of apples and expanding the variety of apple products is of great significance.

[0003] Currently, processed apple products include concentrated apple juice, novel NFC apple juice, apple chips, dried apples, canned apples, cider, apple cider vinegar, apple brandy (distilled spirit), edible apple enzymes, apple probiotic fermented beverages, apple powder, apple jam, and apple pectin. However, apart from concentrated apple juice, which has reached a certain scale, the scale of other apple-based processed products is generally small, with a deep processing conversion rate of less than 10%. Improving the deep processing conversion rate of apples is currently a crucial way to extend, strengthen, and supplement the apple industry chain and achieve high-quality development. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an enzyme-infused black apple and its production process. The enzyme-infused black apple obtained by the production process provided by this invention is rich in nutrients and has a suitable taste, opening up new avenues for extending the apple industry chain and increasing product added value.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A process for producing enzyme-enzyme black apples includes the following steps:

[0007] S1. Raw material pretreatment: Grade, wash, drain and plate fresh apples;

[0008] S2. Preparation of fermentation culture: Mix Lactobacillus fermentans and Lactobacillus delbrueckii subsp. bulgaricus in a ratio of 1:1 to 1:3 to prepare fermentation culture.

[0009] S3. Inoculation: Spray the fermentation liquid evenly onto the surface of the apples;

[0010] S4. Primary fermentation: Inoculated apples are fermented at 37℃~39℃ for 24h~48h;

[0011] S5. Secondary fermentation: Anaerobic fermentation for 45-60 days under conditions of relative humidity of 55%-85% and temperature of 50℃-80℃.

[0012] S6. Maturation and fermentation: Ferment for 28 to 31 days at a temperature of 20℃ to 25℃.

[0013] S7. Sterilization, packaging, and testing.

[0014] Preferably, the grading in S1 involves grading fresh apples according to their transverse diameter, selecting apples with a transverse diameter of 60mm to 67mm for later use.

[0015] Preferably, in step S1, the apples are placed on a sterilized stainless steel mesh tray after draining. Only one layer of apples can be placed on the tray, and the sample loading rate is 2.8 kg / m². 2 ~3.1kg / m 2 .

[0016] Preferably, in S2, the *Lactobacillus fermentatus* is *Lactobacillus fermentatus* CICC24824, and the *Lactobacillus delbrueckii* subsp. bulgaricus is *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097; the bacterial concentration of both *Lactobacillus fermentatus* and *Lactobacillus delbrueckii* subsp. bulgaricus is 10. 9 CFU / mL ~10 10 CFU / mL.

[0017] Preferably, the inoculation amount of the fermentation broth in S3 is 6% to 10% of the apple weight.

[0018] Preferably, the secondary fermentation in S5 is divided into early stage, middle stage, and late stage.

[0019] Preferably, the initial fermentation period is 15-20 days under conditions of 65%-75% relative humidity and 60-70℃ temperature; the middle fermentation period is 15-20 days under conditions of 75%-85% relative humidity and 70-80℃ temperature; and the later fermentation period is 15-20 days under conditions of 55%-65% relative humidity and 50-60℃ temperature.

[0020] Preferably, the ripening and fermentation in S6 needs to be carried out under ventilated conditions.

[0021] The present invention also provides an enzyme-containing black apple produced by the production process described in the above technical solution.

[0022] Preferably, the enzyme-treated black apple contains soluble pectin ≥ 179.62 mg / g fresh weight, protopectin ≥ 60.32 mg / g fresh weight, total phenols ≥ 10.05 mg / g, and total flavonoids ≥ 9.84 mg / g.

[0023] Beneficial Technical Effects: This invention provides an enzyme-based black apple and its production process, including: raw material pretreatment, preparation of fermentation broth, inoculation, primary fermentation, secondary fermentation, ripening fermentation, sterilization, packaging, and testing. The resulting enzyme-based black apple has a soluble pectin content ≥179.62 mg / g fresh weight, a protopectin content ≥60.32 mg / g fresh weight, a total phenol content ≥10.05 mg / g, and a total flavonoid content ≥9.84 mg / g. This invention's production process is significantly different from that of candied fruit products. Besides the fermentation probiotic strains, no exogenous substances are added, and the nutritional value of the final product is significantly superior to traditional apple candied fruit and fresh fruit products. This is of great significance for enriching the variety of deep-processed apple products, promoting the development of the fruit industry, and extending the fruit industry chain. Attached Figure Description

[0024] Figure 1 The changes in the appearance of apples obtained in Comparative Examples 1-5 and Examples 1-3 are shown. Detailed Implementation

[0025] This invention provides a production process for enzyme-based black apples, comprising the following steps:

[0026] S1. Raw material pretreatment: Grade, wash, drain and plate fresh apples;

[0027] S2. Preparation of fermentation culture: Mix Lactobacillus fermentans and Lactobacillus delbrueckii subsp. bulgaricus in a ratio of 1:1 to 1:3 to prepare fermentation culture.

[0028] S3. Inoculation: Spray the fermentation liquid evenly onto the surface of the apples;

[0029] S4. Primary fermentation: Inoculated apples are fermented at 37℃~39℃ for 24h~48h;

[0030] S5. Secondary fermentation: Anaerobic fermentation for 45-60 days under conditions of relative humidity of 55%-85% and temperature of 50℃-80℃.

[0031] S6. Maturation and fermentation: Ferment for 28 to 31 days at a temperature of 20℃ to 25℃.

[0032] S7. Sterilization, packaging, and testing.

[0033] This invention pre-processes the raw materials: grading, washing, draining, and plating fresh apples.

[0034] In this invention, the fresh apples are preferably those that are growing well, are uniform in size, have tender and crisp texture, are fresh, free from pests and diseases, undamaged, and free from rot; the variety of apples is more preferably Fuji apples.

[0035] In this invention, the grading is preferably performed by grading fresh apples according to their transverse diameter, selecting apples with a transverse diameter of 60mm to 67mm for later use. Specifically, apples with a transverse diameter of 60mm to 67mm are classified as Grade 3, apples with a transverse diameter of 68mm to 75mm as Grade 2, and apples with a transverse diameter ≥76mm as Grade 1. This invention ensures consistency in the subsequent fermentation process through grading.

[0036] In this invention, the preferred method of tray loading is to place the drained apples on a sterilized stainless steel mesh tray, with only one layer of apples allowed on each tray; the preferred sample loading rate is 2.8 kg / m². 2 ~3.1kg / m 2 More preferably 3kg / m 2 .

[0037] The present invention prepares fermentation broth by mixing Lactobacillus fermentans and Lactobacillus delbrueckii subsp. bulgaricus in a preferred ratio of 1:1 to 1:3 to prepare fermentation broth.

[0038] In this invention, the *Lactobacillus fermentatus* is *Lactobacillus fermentatus* CICC24824, and the *Lactobacillus delbrueckii* subsp. bulgaricus is *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097; the bacterial concentration of both *Lactobacillus fermentatus* and *Lactobacillus delbrueckii* subsp. bulgaricus is 10. 9 CFU / mL ~10 10 CFU / mL. The fermenting Lactobacillus mucinus CICC24824 used in this invention is resistant to high temperature and humidity and has high antioxidant activity; while Lactobacillus delbrueckii subsp. Bulgaria CICC6097 can not only work with fermenting Lactobacillus mucinus CICC24824 to decompose organic matter in apples, but also produce a special aroma, giving the final enzyme black apple a unique flavor.

[0039] The inoculation process of this invention involves evenly spraying the fermentation liquid onto the surface of the apple.

[0040] In this invention, the inoculation amount of the fermentation liquid is preferably 6% to 10% of the apple weight.

[0041] The initial fermentation of this invention involves fermenting inoculated apples at 37℃~39℃ for 24h~48h.

[0042] In this invention, the inoculated apples are preferably fermented at 38°C for 36 hours. Ventilation is required during the initial fermentation stage to ensure the oxygen requirements of the probiotics and maintain the redox balance in the fermentation broth. This invention ensures the growth and reproduction of *Lactobacillus mucilaginosus* and *Lactobacillus delbrueckii* subsp. bulgaricus during the initial fermentation, laying the foundation for subsequent fermentation processes.

[0043] The present invention further involves a secondary fermentation: anaerobic fermentation for 45 to 60 days under conditions of relative humidity of 55% to 85% and temperature of 50°C to 80°C.

[0044] In this invention, the secondary fermentation is divided into three stages: early, middle, and late. The early stage is preferably fermented for 15-20 days under conditions of 65%-75% relative humidity and 60-70℃ temperature; the middle stage is preferably fermented for 15-20 days under conditions of 75%-85% relative humidity and 70-80℃ temperature; and the late stage is preferably fermented for 15-20 days under conditions of 55%-65% relative humidity and 50-60℃ temperature. The total number of days for the secondary fermentation in this invention is preferably 55-60 days. This invention, by conducting secondary fermentation in a high-temperature and high-humidity environment, ensures that the final enzyme-based black apple product requires no further processing or additives. Temperature control during the secondary fermentation is particularly important. The secondary fermentation stage primarily involves fermentation of the heat- and humidity-resistant *Lactobacillus mucilaginosus* CICC24824. In the early stages, *Lactobacillus mucilaginosus* CICC24824 further consumes the organic matter in the apple, producing metabolic byproducts such as lactic acid. If the temperature is too high in the early stages, although the growth and reproduction rate of this bacterium accelerates, it produces excessive carbon dioxide, causing the pH value of the fermentation broth to drop, affecting the overall fermentation and flavor. If the temperature is too low in the early stages, it will affect the reproduction rate of lactic acid bacteria, leading to a prolonged fermentation time. In the middle stages, as the fermentation temperature rises, the growth and reproduction rate of *Lactobacillus mucilaginosus* CICC24824 gradually decreases, and the metabolic rate slows down, but the apple flesh gradually becomes soft and the aroma compounds further increase. In the later stages, the growth and reproduction rate of *Lactobacillus mucilaginosus* CICC24824 further decreases, and fermentation enters its final stage.

[0045] In this invention, the anaerobic fermentation is preferably carried out by replacing the oxygen in the fermentation chamber with inert gases such as carbon dioxide and nitrogen to maintain an anaerobic environment.

[0046] The present invention further undergoes maturation and fermentation: fermentation is carried out at a temperature of 20℃~25℃ for 28 days~31 days.

[0047] In this invention, the ripening and fermentation process needs to be carried out under ventilated conditions. This invention uses ventilation to lower the temperature in the fermentation chamber, preventing the enzyme-treated black apples from molding.

[0048] The final steps of this invention include sterilization, packaging, and testing.

[0049] In this invention, the sterilization is preferably carried out using both ultraviolet light and ozone; the packaging is preferably placing the enzyme black apple in a sterilized aluminum foil bag.

[0050] In this invention, the preferred testing standards are GB / T4789.2-2003 for the determination of total bacterial count in food hygiene microbiology, GB / T4789.3-2003 for the determination of coliform bacteria in food hygiene microbiology, and GB / T4789.4-2003 for the determination of Salmonella in food hygiene microbiology.

[0051] The present invention also provides an enzyme-containing black apple produced by the production process described in the above technical solution.

[0052] In this invention, the content of soluble pectin in the enzyme-containing black apple is ≥179.62 mg / g fresh weight, the content of protopectin is ≥60.32 mg / g fresh weight, the content of total phenols is ≥10.05 mg / g, and the content of total flavonoids is ≥9.84 mg / g.

[0053] To better understand this invention, the following embodiments further illustrate its content, but the content of this invention is not limited to the following embodiments. Unless otherwise specified, the materials and reagents used in the embodiments and experimental examples of this invention are commercially available; the methods used in the embodiments and experimental examples of this invention are conventional methods unless otherwise specified. The *Lactobacillus fermentans* CICC24824 and *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097 of this invention were both purchased from the China Industrial Microbiological Culture Collection Center.

[0054] Example 1

[0055] (1) Select apples that are healthy, uniform in size, tender and crisp, fresh, free from pests and diseases, undamaged, and rotten. Grade them, wash them thoroughly, and drain them. Place the drained apples on a sterilized stainless steel mesh tray, with only one layer, and a sample loading of 3 kg / m². 2 ;

[0056] (2) Take *Lactobacillus fermentum* CICC24824 and *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097, and inoculate them separately into MRS medium. Incubate at a suitable temperature until the bacterial concentration reaches 10⁻⁶. 9 CFU / mL ~10 10 When the concentration of CFU / mL is 1, the bacterial cultures of Lactobacillus mucinus CICC24824 and Lactobacillus delbrueckii subsp. bulgaricus CICC6097 are mixed at a ratio of 1:2 and sprayed evenly on the surface of the apples at an inoculation amount of 6% of the apple weight. Fermentation is carried out at 38°C for 24 hours.

[0057] (3) Secondary fermentation: The initial stage was fermented for 20 days under conditions of 70% relative humidity and 65℃; the middle stage was fermented for 20 days under conditions of 80% relative humidity and 75℃; and the later stage was fermented for 20 days under conditions of 60% relative humidity and 55℃.

[0058] (4) Maturation and fermentation: Ferment at 22℃ for 30 days under ventilated conditions;

[0059] (5) Sterilization, packaging, and testing.

[0060] Example 2

[0061] (1) Select apples that are healthy, uniform in size, tender and crisp, fresh, free from pests and diseases, undamaged, and rotten. Grade them, wash them thoroughly, and drain them. Place the drained apples on a sterilized stainless steel mesh tray, with only one layer, and a sample loading of 3.1 kg / m². 2 ;

[0062] (2) Take *Lactobacillus fermentum* CICC24824 and *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097, and inoculate them separately into MRS medium. Incubate at a suitable temperature until the bacterial concentration reaches 10⁻⁶. 9 CFU / mL ~10 10 When the concentration of CFU / mL is 1, the bacterial cultures of Lactobacillus mucinus CICC24824 and Lactobacillus delbrueckii subsp. bulgaricus CICC6097 are mixed at a ratio of 1:3 and sprayed evenly on the surface of the apples at an inoculation amount of 6% of the apple weight. Fermentation is carried out at 37°C for 48 hours.

[0063] (3) Secondary fermentation: The initial stage was fermented for 18 days under conditions of 65% relative humidity and 60℃; the middle stage was fermented for 15 days under conditions of 75% relative humidity and 70℃; and the later stage was fermented for 20 days under conditions of 55% relative humidity and 50℃.

[0064] (4) Maturation and fermentation: Ferment at 20℃ for 31 days under ventilated conditions;

[0065] (5) Sterilization, packaging, and testing.

[0066] Example 3

[0067] (1) Select apples that are healthy, uniform in size, tender and crisp, fresh, free from pests and diseases, undamaged, and rotten. Grade them, wash them thoroughly, and drain them. Place the drained apples on a sterilized stainless steel mesh tray, with only one layer, and a sample loading of 2.8 kg / m². 2 ;

[0068] (2) Take *Lactobacillus fermentum* CICC24824 and *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097, and inoculate them separately into MRS medium. Incubate at a suitable temperature until the bacterial concentration reaches 10⁻⁶. 9 CFU / mL ~10 10When the concentration of CFU / mL is 1, the bacterial cultures of Lactobacillus mucinus CICC24824 and Lactobacillus delbrueckii subsp. bulgaricus CICC6097 are mixed in a 1:1 ratio and sprayed evenly on the surface of the apples at an inoculation amount of 6% of the apple weight. Fermentation is carried out at 39°C for 36 hours.

[0069] (3) Secondary fermentation: The initial stage was fermented for 15 days under conditions of 75% relative humidity and 70℃; the middle stage was fermented for 20 days under conditions of 85% relative humidity and 80℃; and the later stage was fermented for 15 days under conditions of 65% relative humidity and 60℃.

[0070] (4) Maturation and fermentation: Under ventilated conditions, ferment at 20℃~25℃ for 28 days~31 days;

[0071] (5) Sterilization, packaging, and testing.

[0072] Comparative Example 1

[0073] Fresh apples.

[0074] Comparative Example 2

[0075] Compared with Example 1, this comparative example only underwent initial fermentation after inoculation with fermentation broth.

[0076] Comparative Example 3

[0077] Compared with Example 1, this comparative example only underwent the initial fermentation and secondary fermentation after inoculation with fermentation broth.

[0078] Comparative Example 4

[0079] Compared with Example 1, this comparative example only carried out the initial fermentation and the early and middle stages of the secondary fermentation after inoculation with fermentation broth.

[0080] Comparative Example 5

[0081] Compared with Example 1, this comparative example only underwent primary and secondary fermentation after inoculation with fermentation broth.

[0082] Experimental Example 1

[0083] The final products obtained from Examples 1-3 and Comparative Examples 1-5 were tested for pectin, total phenols, total flavonoids, total acid, total sugar, and amino acids.

[0084] (1) Pectin content detection: The detection standard was NY / T 2016-2011 "Determination of Pectin Content in Fruits and Their Products - Spectrophotometric Method". The detection results are shown in Table 1. As can be seen from Table 1, the contents of protopectin and soluble pectin in Examples 1-3 were significantly increased compared with those in Comparative Examples 1-5. This indicates that under high temperature and high humidity conditions, pectin molecules in apples interact with water molecules, undergoing a hydrolysis reaction to produce soluble pectin. The molecular structure of pectin also changes, leading to an increase in pectin content. At the same time, apples under high temperature and high humidity conditions are also more likely to produce polyphenols, which can inhibit the activity of pectin hydrolytic enzymes, thereby inhibiting the hydrolysis reaction of pectin and maintaining the pectin content and quality.

[0085] Table 1. Results of pectin content detection

[0086]

[0087] (2) Detection of total phenols and total flavonoids: The method for detecting total phenols was NY / T 2795-2015 "Determination of Major Phenolic Substances in Apples by High Performance Liquid Chromatography"; the method for detecting total flavonoids was spectrophotometry, using aluminum nitrate as the colorimetric solution and rutin as the standard, with a detection wavelength of 510 nm absorbance, and measured in triplicate. The results of the detection of total phenols and total flavonoids are shown in Table 2. As can be seen from Table 2, the total phenol and total flavonoid contents of Examples 1-3 were significantly increased compared with those of Comparative Examples 1-5. This indicates that under high temperature and high humidity conditions, the lactic acid bacteria involved in apple fermentation will release some biologically active substances, such as lactic acid and ethanol. These substances can react chemically with the polyphenols and flavonoids in apples, thereby increasing the content of total phenols and total flavonoids. At the same time, high temperature and high humidity conditions will activate various enzymes in apples, including polyphenol oxidase (PPO) and peroxidase (POD). These enzymes can catalyze the synthesis of polyphenols and flavonoids, thereby increasing the content of total phenols and total flavonoids.

[0088] Table 2 Results of total phenol and total flavonoid content detection

[0089]

[0090]

[0091] (3) Detection of total acid, total sugar, and amino acid content: The detection standard for total acid was GB 12456-2021 National Food Safety Standard - Determination of Total Acid in Food; the detection method for total sugar was Fehling's reagent hot titration method; the detection standard for amino acids was GB5009.124-2016 National Food Safety Standard - Determination of Amino Acids in Food; the detection results of total acid, total sugar, and amino acids are shown in Table 3. As can be seen from Table 3, the total acid and total sugar content of Examples 1-3 were significantly increased compared with Comparative Examples 1-5, but the amino acid content was significantly lower than that of Comparative Examples 1-5. This indicates that under high temperature and high humidity conditions, the organic acids and sugars originally present in apples may undergo decomposition and transformation. Under the action of microorganisms, these substances are decomposed into smaller molecules, such as volatile acids, alcohols, ketones, etc., and some are also transformed into other substances, such as lactic acid, ethanol, etc. This process leads to an increase in the content of total acid and total sugar. Under high temperature and high humidity conditions, the lactic acid bacteria involved in fermentation will use the amino acids originally present in apples as a nutrient source for growth and reproduction. Therefore, as microorganisms utilize amino acids, their content decreases significantly. Simultaneously, under high temperature and humidity conditions, the amino acids in apples may undergo a series of chemical reactions, such as deamination, decarboxylation, and oxidation. These reactions also lead to a decrease in amino acid content.

[0092] Table 3. Results of total acid, total sugar, and amino acid content detection.

[0093]

[0094]

[0095] Experimental Example 2

[0096] The bacterial count in Example 1 and Comparative Example 1 was determined using the dilution plating method, and the results are shown in Table 4. Table 4 shows that the total bacterial count in the enzyme-treated black apple was significantly lower than that in the fresh apple, possibly due to the production of antimicrobial peptides during fermentation, which effectively inhibited bacterial growth.

[0097] Table 4 Results of bacterial count detection

[0098]

[0099] Experimental Example 3

[0100] The enzyme-treated black apples from Example 1 underwent sensory evaluation. The scoring criteria and evaluation results are shown in Table 5. The enzyme-treated black apples were glossy black with uniform color; they possessed the characteristic aroma of apples, rich and long-lasting, leaving a lingering aftertaste; they had a pure taste, with the unique flavor of apples, sweet but not cloying, sour but not astringent, and a refreshing and pleasant flavor; they were uniform in shape and size, free of impurities, plump, firm in structure, and delicate in texture. Overall, this black apple received a very high sensory evaluation, demonstrating excellent performance in color, aroma, taste, and texture.

[0101] Table 5 Sensory evaluation results

[0102]

[0103] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A production process for enzyme-infused black apples, characterized in that, Includes the following steps: S1. Raw material pretreatment: Grade, wash, drain and plate fresh apples; S2. Preparation of fermentation broth: *Lactobacillus fermentatus* and *Lactobacillus delbrueckii* subsp. bulgaricus are mixed in a ratio of 1:1 to 1:3 to prepare a fermentation broth; the *Lactobacillus fermentatus* in S2 is *Lactobacillus fermentatus* CICC24824, and the *Lactobacillus delbrueckii* subsp. bulgaricus is *Lactobacillus delbrueckii* subsp. bulgaricus CICC6097; the concentration of both *Lactobacillus fermentatus* and *Lactobacillus delbrueckii* subsp. bulgaricus in the broth is 10. 9 CFU / mL ~10 10 CFU / mL; S3. Inoculation: Spray the fermentation liquid evenly onto the surface of the apples; S4. Primary fermentation: Inoculated apples are fermented at 37℃~39℃ for 24h~48h; S5. Secondary fermentation: Anaerobic fermentation for 45-60 days under conditions of 55%-85% relative humidity and 50℃-80℃; the secondary fermentation in S5 is divided into early stage, middle stage, and late stage; the early stage is fermentation for 15-20 days under conditions of 65%-75% relative humidity and 60℃-70℃; the middle stage is fermentation for 15-20 days under conditions of 75%-85% relative humidity and 70℃-80℃; the late stage is fermentation for 15-20 days under conditions of 55%-65% relative humidity and 50℃-60℃. S6. Maturation and fermentation: Ferment for 28 to 31 days at a temperature of 20℃ to 25℃; the maturation and fermentation in S6 needs to be carried out under ventilated conditions. S7. Sterilization, packaging, and testing.

2. The production process of enzyme-infused black apples according to claim 1, characterized in that, The grading in S1 involves grading fresh apples according to their transverse diameter, selecting apples with a transverse diameter of 60mm to 67mm for later use.

3. The production process of enzyme-treated black apples according to claim 1 or 2, characterized in that, In step S1, the drained apples are placed on a sterilized stainless steel mesh tray. Only one layer of apples can be placed on the tray, with a sample loading capacity of 2.8 kg / m². 2 ~3.1kg / m 2 .

4. The production process of enzyme-infused black apples according to claim 3, characterized in that, The inoculation amount of the fermentation broth in S3 is 6% to 10% of the apple weight.

5. An enzyme-processed black apple produced by any one of the production processes described in claims 1 to 4, wherein the enzyme-processed black apple contains soluble pectin content ≥179.62 mg / g fresh weight, protopectin content ≥60.32 mg / g fresh weight, total phenol content ≥10.05 mg / g, and total flavonoid content ≥9.84 mg / g.

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