Mixed fruit vinegar and preparation method thereof
By using fruit raw materials such as apples, light walnuts and brown plums, combined with enzymatic lysis and pasteurization, mixed fruit vinegar is prepared, which solves the problem of easy browning and precipitation of traditional fruit vinegar, and produces products with excellent flavor and high stability, meeting market demand and reducing costs.
Patent Information
- Application Number
- CN202411919250.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-04-01
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing Brown Li fruit processing products are limited and cannot meet market demand. Traditional fruit vinegar is prone to browning and precipitation problems.
Apples, light walnuts and Brown Plum are used as raw materials, and through enzymatic lysis and pasteurization, combined with the fermentation of fruit yeast and acetic acid bacteria, mixed fruit vinegar is prepared to control fermentation conditions and product separation, avoiding browning and precipitation.
It successfully solved the problems of browning and precipitation of fruit vinegar, and produced excellent mixed fruit vinegar with brownish-yellow sugar and acid ratio, refreshing and odorless, and compound fruit aroma, meeting market demand and reducing production costs.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fruit vinegar processing, and in particular to mixed fruit vinegar and a preparation method thereof. Background Art
[0002] The advantages of Brown Lee are that Brown Lee not only has a special aromatic smell, but also has firm flesh, sufficient juice, moderate sweetness and sourness, and is rich in various nutrients. It is a fresh fruit. It contains carbohydrates, dietary fiber, fat, vitamins and minerals. It can promote the metabolism of gastric juice and gastric enzymes, gastrointestinal motility, improve gastrointestinal motility, promote the production of body fluids and quench thirst, and can effectively relieve symptoms such as indigestion and food accumulation. Because Brown Lee contains high levels of vitamin C and vitamin E, it can remove free radicals in the body, reduce ultraviolet damage to the skin, and help whiten the skin. At present, Brown Lee has become the main grafted variety of plum tree cultivation in Linzhi City, Tibet, and is deeply loved by market consumers. However, since the market only has a large number of fresh fruits on sale, there are no other forms of products. The existing products cannot meet the current people's purchasing needs, resulting in limited sales of some Brown Lees.
[0003] Mixed fruit vinegar refers to a functional beverage with rich nutrition and excellent flavor, which is made from two or more kinds of fruits and fermented by acetic acid bacteria and other microorganisms. It has the nutritional and health functions of both fruits and vinegar, and is a new type of beverage that combines nutrition, health care, diet therapy and other functions. Fruit vinegar contains rich organic acids and bioactive substances, and has health functions such as improving lipid metabolism, reducing obesity, and preventing arteriosclerosis.
[0004] At present, the plum vinegar studied at home and abroad mainly includes European plum, Angostura plum and domestic plum, while Brown plum is rarely studied. Brown plum is a niche fruit, and its price is slightly higher than that of popular fruits such as apples, and its output is also lower than that of popular fruits. This leads to the fact that the variety of deep-processed products cannot be enriched. Therefore, it is suitable for the production of composite products. With two or more fruit raw materials, it is scientifically compounded to meet the requirements of nutrition and taste, which not only meets the needs of consumers, but also reduces the cost of manufacturers. Traditional fruit vinegar is prone to browning and precipitation. The present invention uses the color of Brown plum itself and the enzymatic hydrolysis method combined with pasteurization to effectively solve the problem of browning and precipitation of fruit vinegar. No need to adjust sugar to save costs. Summary of the invention
[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a mixed fruit vinegar and a preparation method thereof. The present invention utilizes the color of brown plum itself and enzymatic hydrolysis combined with pasteurization to effectively solve the problem that traditional fruit vinegar is prone to browning and precipitation, and does not require sugar adjustment, thus saving costs.
[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:
[0007] A method for preparing mixed fruit vinegar, characterized in that it comprises the following steps:
[0008] (4) preparing fruit puree using apple, walnut and brown plum as raw materials;
[0009] (5) inoculating fruit wine yeast into the fruit pulp of step (1), adding water and stirring evenly, adjusting the pH value, culturing and fermenting, and obtaining mixed fruit wine;
[0010] (1) adjusting the alcohol content of the mixed fruit wine obtained in step (2) to a volume fraction of 6.0%-8.0%, then adding the activated acetic acid bacteria solution, culturing and fermenting at a constant temperature, and finally obtaining a mixed fruit vinegar.
[0011] Preferably, in step (1), the amount of apple added is 50%-60%, the amount of walnut added is 25%-30%, and the amount of brown plum added is 15%-20%.
[0012] Preferably, in step (2), the yeast fermentation temperature is 22-25° C., the fermentation time is 7-14 days, the fruit wine yeast inoculation amount is 0.20-0.30%, the volume ratio of the added water to the fruit pulp is 2:1, and the pH is adjusted to 7 with sodium bicarbonate.
[0013] Preferably, in step (3), the acetic acid fermentation temperature is 28-32° C., the fermentation time is 10-15 days, and the inoculation amount of the acetic acid bacteria liquid is 8-10%.
[0014] Another object of the present invention is to protect a mixed fruit vinegar prepared by any of the above-mentioned preparation methods.
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] 1. The mixed fruit vinegar of the present invention uses apple, walnut and brown plum as raw materials, yeast and acetobacter as fermentation agents, and uses modern fermentation technology, product separation technology and low-temperature sterilization technology as means, through the control of fermentation conditions and the efficient separation of fermentation products, to develop a batch of southeastern Tibetan specialty fruit fermentation products.
[0017] 2. The mixed fruit vinegar and preparation method thereof of the present invention adopt Box-Behnken central composite experimental design, carry out three-factor three-level response surface experiment, take alcohol content as optimization index, optimize the fruit wine fermentation process, and obtain the optimal alcohol fermentation process as follows: the material ratio is apple: light walnut: brown plum is 5:3:2, the fermentation temperature is 23°C, the yeast inoculation amount is 0.27%, the fermentation time is 7d, and the alcohol content reaches 13.37g / 100mL.
[0018] 3. The mixed fruit vinegar and preparation method thereof of the present invention optimize the fruit vinegar fermentation process with acetic acid content as an indicator, and obtain the optimal fruit vinegar fermentation process as follows: the fermentation temperature is 30°C, the acetic acid bacteria inoculation amount is 8.5%, the acetic acid bacteria tolerance alcohol content is 7%, the fermentation time is 14d, and the acetic acid content reaches 6.58g / 100mL.
[0019] 4. The mixed fruit vinegar prepared by the method of the present invention is brown-yellow in color, has a moderate sugar-acid ratio, is refreshing and has no peculiar smell, has a complex fruity aroma, is clear and transparent, and has no precipitation when shaken.
[0020] 5. The present invention focuses on the characteristic forest and fruit resources of Tibet, takes brown plum, apple, walnut and other Nyingchi specialty fruits as the main raw materials, and utilizes traditional fermentation technology to develop brown plum mixed fruit vinegar products, promote the comprehensive utilization rate of brown plum, improve the industrial production technology of Tibetan fruit vinegar, seize the sales share of fruit vinegar in the Tibetan market, and achieve the ultimate goal of enriching the types of fruit vinegar on sale and promoting the economic income of Nyingchi fruit farmers. DETAILED DESCRIPTION
[0021] The following is a detailed description of the preferred embodiments of the present invention.
[0022] Example 1
[0023] A method for preparing mixed fruit vinegar comprises the following steps:
[0024] (1) Using apples, walnuts and brown plums as raw materials to prepare fruit pulp, 500 g of mixed fruit pulp is placed in a fermentation tank, wherein the amount of apple added is 50%, the amount of walnuts added is 30%, and the amount of brown plum added is 20%;
[0025] (2) inoculating 0.27% of fruit wine yeast (LA-DE dark fruit yeast produced by Diboshi Bacteria Co., Ltd., France) into the fruit pulp of step (1), adding water and stirring evenly, the volume ratio of the added water to the mixed fruit pulp is 2:1, then adjusting the pH value to 7 with edible sodium bicarbonate, sealing the jar with water, fermenting in an incubator at 23° C. for 7 days, culturing and fermenting to obtain mixed fruit wine, and determining the alcohol content;
[0026] (3) adjusting the alcohol content of the mixed fruit wine obtained in step (2) to 7% by volume, then adding 8.5% of activated acetic acid bacteria solution, and performing acetic acid fermentation in a constant temperature incubator at 30.0° C. for 14 days to finally obtain mixed fruit vinegar.
[0027] Example 2
[0028] The preparation method is exactly the same as that of Example 1, except that the amount of apple added in step (1) of Example 1 is replaced by 60%, the amount of walnut added is replaced by 25%, and the amount of brown plum added is replaced by 15%.
[0029] Example 3
[0030] The preparation method is exactly the same as that of Example 1, except that the amount of apple added in step (1) of Example 1 is replaced by 55%, the amount of walnut added is replaced by 27%, and the amount of brown plum added is replaced by 18%.
[0031] Example 4
[0032] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of fruit wine yeast in step (2) of Example 1 is replaced with 0.20%.
[0033] Example 5
[0034] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of fruit wine yeast in step (2) of Example 1 is replaced with 0.30%.
[0035] Example 6
[0036] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the fruit wine yeast in step (2) of Example 1 is replaced with 22°C.
[0037] Example 7
[0038] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the fruit wine yeast in step (2) of Example 1 is replaced with 25°C.
[0039] Example 8
[0040] The preparation method is exactly the same as that in Example 1, except that the fermentation time of the fruit wine yeast in step (2) of Example 1 is replaced with 14 days.
[0041] Example 9
[0042] The preparation method is exactly the same as that in Example 1, except that the fermentation time of the fruit wine yeast in step (2) of Example 1 is replaced with 10 days.
[0043] Example 10
[0044] The preparation method is exactly the same as that of Example 1, except that the alcohol content in step (3) of Example 1 is adjusted to 6.0%.
[0045] Embodiment 11
[0046] The preparation method is exactly the same as that of Example 1, except that the alcohol content in step (3) of Example 1 is adjusted to 8.0%.
[0047] Example 12
[0048] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 8%.
[0049] Embodiment 13
[0050] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 10%.
[0051] Embodiment 14
[0052] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 28°C.
[0053] Embodiment 15
[0054] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 32°C.
[0055] Example 16
[0056] The preparation method is exactly the same as that in Example 1, except that the fermentation time of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 10 days.
[0057] Embodiment 17
[0058] The preparation method is exactly the same as that in Example 1, except that the fermentation time of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 15 days.
[0059] Comparative Example 1
[0060] The preparation method is exactly the same as that of Example 1, except that the mass ratio of apple: light walnut: brown plum in step (1) of Example 1 is replaced with 4:3:3.
[0061] Comparative Example 2
[0062] The preparation method is exactly the same as that of Example 1, except that the mass ratio of apple: light walnut: brown plum in step (1) of Example 1 is replaced with 5:2:3.
[0063] Comparative Example 3
[0064] The preparation method is exactly the same as that of Example 1, except that the mass ratio of apple: light walnut: brown plum in step (1) of Example 1 is replaced with 5:4:1.
[0065] Comparative Example 4
[0066] The preparation method is exactly the same as that of Example 1, except that the mass ratio of apple: light walnut: brown plum in step (1) of Example 1 is replaced with 5:1:4.
[0067] Comparative Example 5
[0068] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of fruit wine yeast in step (2) of Example 1 is replaced with 0.01%.
[0069] Comparative Example 6
[0070] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of fruit wine yeast in step (2) of Example 1 is replaced with 0.15%.
[0071] Comparative Example 7
[0072] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the fruit wine yeast in step (2) of Example 1 is replaced with 28°C.
[0073] Comparative Example 8
[0074] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the fruit wine yeast in step (2) of Example 1 is replaced with 31°C.
[0075] Comparative Example 9
[0076] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the fruit wine yeast in step (2) of Example 1 is replaced with 34°C.
[0077] Comparative Example 10
[0078] The preparation method is exactly the same as that of Example 1, except that the alcohol content in step (3) of Example 1 is adjusted to 5.0% (V / V).
[0079] Comparative Example 11
[0080] The preparation method is exactly the same as that of Example 1, except that the alcohol content in step (3) of Example 1 is adjusted to 9.0% (V / V).
[0081] Comparative Example 12
[0082] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 3.0%.
[0083] Comparative Example 13
[0084] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 5.0%.
[0085] Comparative Example 14
[0086] The preparation method is exactly the same as that of Example 1, except that the inoculation amount of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 12%.
[0087] Comparative Example 15
[0088] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 20°C.
[0089] Comparative Example 16
[0090] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 25°C.
[0091] Comparative Example 17
[0092] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 35°C.
[0093] Comparative Example 18
[0094] The preparation method is exactly the same as that of Example 1, except that the fermentation temperature of the acetic acid bacteria liquid in step (3) of Example 1 is replaced with 40°C.
[0095] Process optimization test
[0096] 1. Optimization test of brewing process of mixed fruit vinegar
[0097] Taking fermentation temperature, yeast addition, and fermentation time as factors and alcohol content as optimization index, the Box-Behnken central composite experimental design was used to conduct a three-factor three-level response surface experiment to optimize the fruit wine fermentation process. The optimization factor levels are shown in Table 1.
[0098] Table 1 Response surface optimization design for fruit wine
[0099] level A Fermentation temperature / ℃ B yeast % C Fermentation days / d 1 20 0.1 5 2 25 0.2 7 3 30 0.3 9
[0100] 2. Response surface design for acetic acid fermentation
[0101] After studying the relationship between single factors of acetic acid bacteria tolerance, acetic acid bacteria inoculation amount, fermentation temperature and total acid content, pH value and sensory evaluation, the optimal range of mixed fruit vinegar fermentation process parameters was determined. In order to further explore the influence of various factors on mixed fruit vinegar, the response surface experiment was conducted on inoculation amount (A), fermentation temperature (B) and alcohol content (C). The acetic acid content was used as an indicator. The factor levels are shown in Table 2.
[0102] Table 2 Response process factors of fruit vinegar brewing
[0103]
[0104] 3. Total acid determination
[0105] According to the determination of total acid in food in GB / T 12456
[0106] 4. Determination of total colony count
[0107] Determined according to the total colony count in GB 4789.15-2016.
[0108] 5. Determination of soluble solids
[0109] The test was carried out according to GB / T 12143-2008.
[0110] 6. Salmonella determination
[0111] According to the Salmonella test in GB 4789-2016.
[0112] 7. Staphylococcus aureus assay
[0113] According to the Staphylococcus aureus test in GB 4789.10-2016
[0114] 8. Mold determination
[0115] According to the mold count in GB 4789.15-2016.
[0116] 9. Yeast assay
[0117] According to the yeast count in GB 4789.15-2016.
[0118] 10. Escherichia coli determination
[0119] According to the E. coli count in GB 4789.3-2016 Method 1.
[0120] 11. Determination of lead
[0121] According to the determination of lead in food in GB 5009.12-2017.
[0122] Experimental Results
[0123] 1. Alcohol fermentation
[0124] 1.1 Material comparison test results
[0125] Different material ratios will lead to different flavors and tastes of subsequent mixed fruit vinegar. Because apples are the main ingredients, walnuts and brown plums are the auxiliary ingredients, it is found that when the material ratio is 50%-60% for apples, 25%-30% for walnuts, and 15%-20% for brown plums, the alcohol content is the highest. Therefore, it is determined that the addition of apples is 50%-60%, the addition of walnuts is 25%-30%, and the addition of brown plums is 15%-20%.
[0126] 1.2 Yeast addition test results
[0127] The more yeast is added, the faster the fermentation and the higher the alcohol content. However, when the yeast content reaches 0.20%, the alcohol content decreases significantly. This is because the mixed fruit wine with a large amount of yeast added consumes the substrate quickly, which makes the alcohol degree of the Brown Lee mixed fermentation liquid no longer increase, and the ethanol content is reduced, which is not conducive to the progress of alcohol fermentation. When the yeast addition is 0.25%, the initial fermentation rate is fast and the substrate consumption rate is fast, resulting in the subsequent bacterial flora no longer continuing to grow or even die, which ultimately reduces the alcohol content of the Brown Lee mixed fruit wine. When the yeast addition is 0.20%, the fermentation speed is fast and the ethanol content is the highest. In the review, the fruit wine yeast inoculation amount is 0.20-0.30%
[0128] 1.3 Fermentation temperature test results
[0129] As the fermentation temperature increases, the alcohol content increases first and then decreases. At 22°C, the fermentation temperature is too low, resulting in slow yeast growth and reproduction, slow fermentation speed, and low alcohol content. At 25°C, the fermentation process of the fermented wine proceeds smoothly, and the alcohol content gradually increases. When the fermentation temperature is 28°C to 34°C, due to the high temperature, the yeast metabolic byproducts are too much, and some yeasts age and die prematurely, affecting the quality of the wine and reducing the alcohol content. In summary, the fermentation temperature of fruit wine is 22°C-25°C.
[0130] 1.4 Effect of fermentation time on alcohol fermentation
[0131] As the fermentation time increases, the alcohol content also increases significantly. When the fermentation time is 7 days, the alcohol content is the highest. After the fermentation time exceeds 7 days, the alcohol content remains basically unchanged. When it is 14 days, it will have a downward trend. This is because the alcohol content continues to increase in the early stage of alcohol fermentation, and the sugar substances are continuously consumed later, producing miscellaneous substances, resulting in ethanol consumption. Considering the fermentation time of 7 days. In summary, the fermentation time of fruit wine is 7-14 days.
[0132] 2. Response surface experiment of alcohol fermentation
[0133] The interactive effect is judged according to the shape factors of the contour map and the surface map. If the contour lines are circular or elliptical and the lines are precisely arranged, the interactive effect is significant, otherwise it is the opposite. The surface is gentle and the interactive factor is significant; when the surface is linear or distorted, the interactive factor is not significant. The interactive effect of alcohol fermentation temperature, yeast inoculation amount and fermentation days is more significant. The regression model was optimized using Design Expert 10 software, and the alcohol production target was set at 13.5g / 100ml. The parameters of the three factors recommended by the software were: fermentation temperature (A) was 23.18℃, yeast inoculation amount (B) was 0.27%, and fermentation days were 7.35d. According to the actual situation, the fermentation temperature (A) was determined to be 23.0℃, the yeast inoculation amount (B) was 0.27%, and the fermentation days (C) were 7d. Three parallel tests were carried out, and the average alcohol production in Brown Lee mixed fruit wine was 13.37g / 100ml. It is not much different from the theoretical prediction. The optimal formula for Brown Lee mixed fruit wine was determined as follows: fermentation temperature (A) was 23°C, yeast inoculation amount (B) was 0.27%, and fermentation days (C) was 7 days.
[0134] 3. Acetic acid fermentation
[0135] 3.1 Effect of alcohol tolerance on acetic acid fermentation
[0136] As the alcohol content increases, the acetic acid content first rises and then decreases. This is because alcohol is conducive to the growth of acetic acid bacteria when it is between 5% and 7% (V / V), but when the alcohol content exceeds 7% (V / V), it will inhibit the growth of acetic acid bacteria. As the fermentation process proceeds, the acetic acid content gradually decreases and the acetic acid fermentation rate gradually slows down. This is because the high acidity in the later stage has an inhibitory effect on acetic acid bacteria. During the fermentation process, the acetic acid content of the sample with an alcohol content of 5% (V / V) is only 4.37g / 100ml, while the acetic acid content of the sample with an alcohol content of 7% (V / V) reaches 5.55mg / 100ml. When the initial alcohol content is 6% (V / V), the pH value tends to stabilize after reaching 3.5. When the alcohol content is too high or too low, the sensory score will be reduced. Therefore, during the fermentation process of Brown Lee mixed fruit vinegar, the alcohol content is adjusted to prevent the acetic acid bacteria from being affected by the high or low alcohol content. Taking comprehensive considerations into account, the alcohol content of this experiment was adjusted to 7% (V / V) as the starting alcohol content of Brown Lee mixed acetic acid fermentation.
[0137] 3.2 Effect of inoculum size on acetic acid fermentation
[0138] The analysis results of the changes in acetic acid content under different addition amounts show that when the addition amount is in the range of 3.0% to 8.0%, the acetic acid content increases with the increase of the addition amount, and the acetic acid content of the 8.0% addition amount is 1g / 100ml higher than that of the 3.0% addition amount. However, after the addition amount increases to 8.0%, the acetic acid content tends to decrease, that is, in the addition amount range of 3.0% to 12.0%, the acetic acid content in acetic acid fermentation is a process of first rising and then falling. When the inoculation amount is 8.0%, the acetic acid content is the highest, 7g / 100ml. This may be due to the fact that under the condition of a certain substrate, the greater the amount of acetic acid bacteria added, the greater the content of acetic acid bacteria in the fermentation liquid, and the more nutrients consumed in a certain period of time. The acetic acid bacteria die in the absence of substrates and produce other substances, so the amount of acetic acid produced decreases. When the acetic acid content of the sample with an addition amount of 8.0% reaches 6.58g / 100ml, the sensory score is the highest, and the pH value reaches 3.5. Therefore, considering the comprehensive consideration and cost, the inoculation amount is 8.0%.
[0139] 3.3 Effect of fermentation temperature on acetic acid fermentation
[0140] The results of the test on the effect of different fermentation temperatures on the mixed acetic acid fermentation of Brown Lee showed that in this test, the acetic acid content showed a trend of first increasing and then decreasing. When the fermentation temperature was 30°C, the acetic acid content was the highest, which was 6.01g / 100ml. When the temperature exceeded 30°C, the acetic acid content showed a continuous downward trend. When the fermentation temperature was 35°C, the acetic acid content decreased slightly, and when the fermentation temperature was 40°C, the acetic acid content was 5.25g / 100ml. The reason may be that the fermentation temperature was too high, the acetic acid bacteria could not survive, and part of the acetic acid was oxidized, resulting in a decrease in the acetic acid content of the fermentation liquid. At the same time, when the fermentation temperature was too high, the fermentation liquid produced too many microorganisms and bacteria, the pH value continued to rise, and the sensory score continued to decline. Therefore, when the fermentation temperature was 30°C, it was most suitable for acetic acid fermentation and the acetic acid yield was the highest. At the same time, in order to avoid a decrease in the acetic acid content, the fermentation should be completed when the acetic acid reaches its maximum value.
[0141] 4. Analysis of response surface test results of acetic acid fermentation
[0142] The contour map of the interaction of the three factors shows that the interaction between fermentation temperature, acetic acid bacteria addition and acetic acid bacteria tolerance to alcohol content is more significant. The regression model was optimized using Design Expert 10 software, and the target of acetic acid production was set at 6.17g / 100ml. The parameters of the three factors recommended by the software were: fermentation temperature (A) was 29.61℃, acetic acid bacteria inoculation amount (B) was 0.24%, and acetic acid bacteria tolerance to alcohol content (C) was 7.32% (V / V). According to the actual situation, the fermentation temperature (A) was determined to be 30℃, the acetic acid bacteria inoculation amount (B) was 0.25%, and the acetic acid bacteria tolerance to alcohol content (C) was 7% (V / V). Three parallel tests were carried out, and the average acetic acid production in Brown Lee mixed fruit vinegar was 6.58g / 100ml. It is not much different from the theoretical prediction value. The optimal formula of Brown Lee mixed fruit wine was determined as follows: according to the actual situation, the fermentation temperature (A) was 30°C, the acetic acid bacteria inoculation amount (B) was 0.25%, and the acetic acid bacteria tolerance alcohol content (C) was 7% (V / V).
[0143] 5. Determination of microbial physical and chemical indicators
[0144] The results of microbial physicochemical indexes of Brown Lee mixed fruit vinegar are shown in Table 3. Referring to NYT2987-2016 Green Food Fruit Vinegar Beverage and DBS630002-2017 Local Food Safety Standard Seabuckthorn Fruit Vinegar (Beverage) , the product meets the requirements.
[0145] Table 3 Physical and chemical index test results
[0146]
[0147]
[0148] A comparative analysis of Brown Lee mixed fruit vinegar and Brown Lee mixed fruit wine revealed that during the fermentation process of Brown Lee mixed fruit vinegar, the composition of fruit wine and fruit vinegar changed significantly. Oxalic acid, citric acid and lactic acid in organic acids were consumed by 94.29%, 56.04% and 85.25% respectively when the fruit wine was converted into fruit vinegar; the acetic acid content increased significantly, and the acetic acid content in fruit vinegar was 10.6 times that in fruit wine; glucose was consumed by 79.00%, glycerol and ethanol were consumed by 73.66% and 68.33% respectively. Methanol was not detected in either the fruit wine or the fruit vinegar samples. GC-MC method was used to determine Brown Lee and Brown Lee mixed fruit vinegar, and a total of 39 volatile components were identified in Brown Lee and 42 volatile components in Brown Lee mixed fruit vinegar. According to "NYT29987-2016 Green Food Fruit Vinegar Beverage" and "DBS630002-2017 Local Food Safety Standard Seabuckthorn Vinegar (Beverage)", Brown Lee mixed fruit vinegar was subjected to microbial physical and chemical testing and the test was qualified.
[0149] In summary, the present invention uses apples, walnuts and brown plums as main raw materials, enzymolyzes apples, walnuts and brown plums by biological enzymolysis, ferments mixed fruit juice into mixed fruit wine by traditional fermentation process, and further ferments into fruit vinegar, and optimizes the process conditions at different stages. Finally, a new type of composite mixed fruit vinegar is developed, which has a brown-yellow color, a moderate sugar-acid ratio, is refreshing and has no peculiar smell, has a composite fruity aroma, is clear and transparent, and has no precipitation when shaken.
[0150] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A method for preparing a mixed fruit vinegar, characterized in that: The steps include: (1) Preparing fruit puree using apple, walnut and brown plum as raw materials; (2) inoculating fruit wine yeast into the fruit pulp of step (1), adding water and stirring evenly, adjusting the pH value, culturing and fermenting, and obtaining mixed fruit wine; (3) adjusting the alcohol content of the mixed fruit wine obtained in step (2) to a volume fraction of 6.0%-8.0%, then adding the activated acetic acid bacteria solution, culturing and fermenting at a constant temperature, and finally obtaining a mixed fruit vinegar.
2. The method for preparing a mixed fruit vinegar according to claim 1, characterized in that: In step (1), the amount of apple added is 50%-60%, the amount of walnut added is 20%-30%, and the amount of brown plum added is 15%-20%.
3. The method for preparing a mixed fruit vinegar according to claim 1, characterized in that: In step (2), the yeast fermentation temperature is 22-25° C., and the fermentation time is 7-14 days; the fruit wine yeast inoculation amount is 0.20-0.30%; the volume ratio of the amount of water added to the fruit pulp is 2:1; and the pH is adjusted to 7 with sodium bicarbonate.
4. The method for preparing a mixed fruit vinegar according to claim 1, characterized in that: In step (3), the acetic acid fermentation temperature is 28-32° C., the fermentation time is 10-15 days, and the inoculation amount of the acetic acid bacteria liquid is 8-10%.
5. A mixed fruit vinegar prepared by the preparation method according to any one of claims 1 to 4.