Method for preparing blueberry wine by treating blueberry fruits with melatonin

Abstract

The invention discloses a method for preparing blueberry wine by treating blueberry fruits with melatonin, and relates to the technical field of fruit wine brewage, and the method comprises the following steps: taking blueberry fruits with the sugar degree of more than or equal to 12%, soaking the blueberry fruits with a melatonin solution, and air-drying the blueberry fruits until the surfaces are dry to obtain air-dried blueberries; dehydrating and crushing the air-dried blueberries to obtain blueberry mash; adding potassium metabisulfite into the blueberry mash, uniformly stirring, standing for 2-3 hours, adding pectinase for hydrolyzing to obtain a hydrolyzed material, and adding white granulated sugar to adjust the mass percent of soluble solids in the hydrolyzed material to 22% to obtain blueberry pulp; adding saccharomyces cerevisiae into the blueberry pulp for alcoholic fermentation, separating peel residues, collecting sake, adding potassium metabisulfite, and ageing to obtain the blueberry finished wine. The content of terpene substances in the blueberry fruits is remarkably increased, and the flower and fruit fragrance of the blueberry wine is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of fruit wine brewing, and more specifically to a method for preparing blueberry wine by treating blueberry fruits with melatonin. Background Art

[0002] With the annual increase in blueberry production, the development of deep-processed blueberry products can effectively reduce the waste of blueberry resources and increase the economic added value of blueberries. As one of the main deep-processed products of blueberries, blueberry wine has a unique flavor and is rich in nutrients such as anthocyanins and vitamins. It has multiple benefits such as anti-oxidation and anti-aging. In recent years, it has attracted the attention of consumers in the fruit wine market. However, after blueberry fruits are fermented into fruit wine, the floral and fruity aroma is severely lost, which seriously affects the commercial value of blueberry wine.

[0003] Terpenes directly derived from wine berries are a key component that determines the "floral and fruity aroma" of fruit wine. Post-harvest dehydration stress drying of wine berries can not only concentrate their flavor components, but also induce a series of biochemical reactions such as synthesis, degradation, oxidation and biotransformation of their secondary metabolites. This technology has the characteristics of simple operation, low cost and high safety, and has been widely used to improve the aroma quality of wine. Due to people's pursuit of wine aroma quality, it is necessary to continue to improve the preparation method of blueberry wine. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for preparing blueberry wine by treating blueberry fruits with melatonin, so as to improve the aroma quality of the wine.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for preparing blueberry wine by treating blueberry fruits with melatonin comprises the following steps:

[0007] Take blueberry fruits with a sugar content of ≥12%, soak them in a melatonin solution, and air-dry them until the surface is dry to obtain air-dried blueberries; wherein the concentration of the melatonin solution is 200 μmol / L to 250 μmol / L, and the mass ratio of the blueberry fruits to the melatonin solution is 1.5 to 2.5:5.

[0008] The air-dried blueberries are dehydrated and crushed to obtain blueberry mash.

[0009] Potassium metabisulfite is added to the blueberry mash and stirred evenly, and the mixture is allowed to stand for 2 to 3 hours. Pectinase is added for hydrolysis to obtain a hydrolyzed material, and white sugar is added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22% to obtain blueberry pulp, wherein the mass ratio of blueberry mash, potassium metabisulfite and pectinase is 100000:8 to 10:4 to 6.

[0010] The method comprises adding brewer's yeast to blueberry pulp for alcohol fermentation, separating skin residue, collecting sake, adding potassium pyrosulfite, and preparing blueberry finished wine after aging, wherein the mass ratio of blueberry pulp, brewer's yeast and potassium pyrosulfite is 20000:7-9:0.5-1.5.

[0011] In the method for preparing blueberry wine by treating blueberry fruits with melatonin, the blueberry fruits are soaked in a melatonin solution, and then air-dried to remove part of the water in the blueberry fruits after soaking, which is beneficial to the subsequent fermentation process and can also increase the flavor and taste of the wine.

[0012] Dehydration further removes water from the blueberries, making the fermentation process purer. The crushed blueberry mash is easier to carry out subsequent enzymatic and hydrolytic treatments.

[0013] Adding potassium pyrosulfite and pectinase hydrolysis: Potassium pyrosulfite is an antioxidant that can prevent blueberry mash from oxidation during processing. Pectinase hydrolysis can decompose the pectin in the blueberry mash, release more juice, and improve the yield and clarity of the wine. The addition of white sugar can adjust the soluble solids content in the blueberry pulp, affecting the fermentation process and the alcohol content and taste of the final wine.

[0014] The addition of brewer's yeast and alcohol fermentation converts the sugar in the blueberry pulp into alcohol and carbon dioxide. After the fermentation is completed, the skins and residues are separated and the clear wine is collected, which is sake. The addition of potassium metabisulfite can prevent the finished wine from oxidizing during the aging process. The aging process can make the wine's flavor more mellow and the taste more harmonious.

[0015] Furthermore, the method for preparing blueberry wine by treating blueberry fruits with melatonin can improve the aroma quality of the wine.

[0016] Preferably, the blueberry fruit is soaked in the melatonin solution for 5 to 8 minutes, which can effectively promote the ripening and color improvement of the blueberry fruit while avoiding the loss of nutrients or softening of the texture due to excessive soaking.

[0017] Preferably, the environment temperature of the blueberry fruit after harvesting is 15°C to 25°C, and the relative humidity is 60% to 80%. If the humidity is too low, rapid water loss will cause a large amount of oxidation of the fruit flavor components, making the flavor worse. Therefore, the relative humidity is selected to be 60% to 80% to control the dehydration rate and proceed slowly. This environment temperature and relative humidity can effectively control the dehydration rate of the blueberry fruit, ensuring that the texture, nutritional components and flavor of the fruit are not damaged during the dehydration process.

[0018] Preferably, the weight loss of the moderately dehydrated blueberry fruit is 20% to 30%. This weight loss range can ensure that the blueberry fruit is dehydrated to a suitable degree, which is beneficial to the subsequent fermentation process and can maintain the flavor and nutritional value of the fruit.

[0019] Preferably, the hydrolysis temperature of adding pectinase is 25°C to 30°C, and the hydrolysis time is 24 hours. Under this temperature and hydrolysis time, pectinase can effectively decompose the pectin in the blueberry mash, improve the clarity of the juice and the taste of the wine.

[0020] Preferably, the alcohol fermentation temperature is 22° C. to 28° C., and the fermentation time is 17 days to 19 days; this temperature range is the optimal temperature range for brewer's yeast fermentation, which can ensure the smooth progress of the fermentation process while affecting the alcohol content and flavor.

[0021] Preferably, the total sugar content in the sake is 4 g / L to 5 g / L. This total sugar content range can provide appropriate sweetness to meet the needs of blueberry wine with different tastes, while not affecting the storage stability and taste of the wine.

[0022] Preferably, the aging temperature is 16° C. to 20° C., and the aging time is 180 days to 360 days. Aging within this temperature and time range can make the flavor of the blueberry wine more mellow and the taste more harmonious, while maintaining the color and stability of the wine.

[0023] The method for preparing blueberry wine by treating blueberry fruits with melatonin is applied in preparing blueberry wine with high floral and fruity aroma.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) Treating blueberry fruits with melatonin can increase the content of terpenes and the "floral and fruity aroma" of blueberry wine; it can also increase the content of melatonin in brewed blueberry wine, making the blueberry wine product more nutritious and healthy.

[0026] (2) The present invention utilizes the antibacterial property of melatonin to significantly reduce the decay rate of blueberry fruit during the post-harvest dehydration period. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1This is the result of the quantitative description analysis of the aroma of the blueberry wine of Example 16 of the present invention. *, ** and *** indicate significant differences among the groups at p<0.05, p<0.01 and p<0.001. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] In view of the problem that blueberries are more easily infected with bacteria and cause fruit rot in the process of brewing blueberry wine with high floral and fruity aroma in the prior art, it is urgent to solve the problem. The present invention provides a method for preparing blueberry wine by treating blueberry fruits with melatonin to prepare blueberry wine with high floral and fruity aroma. The specific preparation steps are as follows:

[0032] Take blueberry fruits with a sugar content of ≥12%, soak them in a melatonin solution, and air-dry them until the surface is dry to obtain air-dried blueberries; wherein the concentration of the melatonin solution is 200 μmol / L to 250 μmol / L, and the mass ratio of the blueberry fruits to the melatonin solution is 1.5 to 2.5:5.

[0033] The air-dried blueberries are dehydrated and crushed to obtain blueberry mash.

[0034] Potassium metabisulfite is added to the blueberry mash and stirred evenly, and the mixture is allowed to stand for 2 to 3 hours. Pectinase is added for hydrolysis to obtain a hydrolyzed material, and white sugar is added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22% to obtain blueberry pulp, wherein the mass ratio of blueberry mash, potassium metabisulfite and pectinase is 100000:8 to 10:4 to 6.

[0035] The method comprises adding brewer's yeast to blueberry pulp for alcohol fermentation, separating skin residue, collecting sake, adding potassium pyrosulfite, and preparing blueberry finished wine after aging, wherein the mass ratio of blueberry pulp, brewer's yeast and potassium pyrosulfite is 20000:7-9:0.5-1.5.

[0036] The preparation method of the present invention combines post-harvest melatonin treatment with post-harvest moderate dehydration treatment of blueberry fruits. Compared with the control ratio without adding melatonin, the technical feature of adding melatonin can significantly increase the content of terpenes in blueberry fruits and increase the "floral and fruity aroma" of blueberry wine; and significantly reduce the rot rate of blueberry fruits during post-harvest dehydration; and can increase the content of melatonin in brewed blueberry wine, making the blueberry wine product more nutritious and healthy.

[0037] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0038] Example 1

[0039] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0040] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 200 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 1.5:5.

[0041] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 15° C. and a relative humidity of 60%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0042] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:8:4.

[0043] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 17 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and then aged at 16℃ for 180d to obtain the finished blueberry wine; among them, the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:7:0.5.

[0044] Example 2

[0045] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0046] Fresh blueberry fruits with a sugar content of 13% were taken, and were immersed in a 200 μmol / L melatonin solution for 7 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 1.5:5.

[0047] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 15° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0048] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 3 hours. The mixture was hydrolyzed at 25°C in the dark for 25 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:8:4.

[0049] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 17 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and then aged at 16℃ for 180d to obtain the finished blueberry wine; among them, the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:7:0.5.

[0050] Example 3

[0051] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0052] Fresh blueberry fruits with a sugar content of 14% were taken, and were immersed in a 200 μmol / L melatonin solution for 8 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 1.5:5.

[0053] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 60%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0054] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 26 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:8:4.

[0055] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 17 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:7:0.5.

[0056] Example 4

[0057] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0058] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 200 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 1.5:5.

[0059] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0060] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:8:4.

[0061] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 17 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:7:0.5.

[0062] Example 5

[0063] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0064] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0065] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 15° C. and a relative humidity of 60%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0066] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0067] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0068] Example 6

[0069] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0070] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0071] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 15° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0072] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0073] The effective number of live bacteria added to blueberry pulp is 1×106 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0074] Example 7

[0075] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0076] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0077] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 60%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0078] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0079] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0080] Example 8

[0081] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0082] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0083] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 20% are crushed to obtain blueberry mash.

[0084] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0085] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0086] Example 9

[0087] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0088] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0089] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0090] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0091] The effective number of live bacteria added to blueberry pulp is 1×10 6CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0092] Example 10

[0093] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0094] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0095] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0096] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 30°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the blueberry sugar content was calculated as refractometric sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0097] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 22℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0098] Embodiment 11

[0099] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0100] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2.5:5.

[0101] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0102] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 30°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:10:6.

[0103] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented at 28℃ for 19d. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:9:1.5.

[0104] Example 12

[0105] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0106] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2.5:5.

[0107] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0108] Add potassium metabisulfite to the blueberry mash, stir evenly, add pectinase after standing for 2 hours, hydrolyze in the dark at 30°C for 24 hours to obtain a hydrolyzed material, add white sugar to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content is calculated as refracted sugar to obtain blueberry pulp; the mass ratio of blueberry mash, potassium metabisulfite and pectinase is 100000:10:6.

[0109] The effective number of live bacteria added to blueberry pulp is 1×10 6CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented at 28℃ for 19d. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 5g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:9:1.5.

[0110] Example 13

[0111] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0112] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0113] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0114] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 30°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0115] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented at 28℃ for 18d. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 5g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 360d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0116] Embodiment 14

[0117] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0118] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0119] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0120] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 30°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0121] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented at 28℃ for 18d. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 5g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 20℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0122] Embodiment 15

[0123] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0124] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0125] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 25° C. and a relative humidity of 80%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0126] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 30°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0127] The effective number of live bacteria added to blueberry pulp is 1×10 6CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented at 28℃ for 18d. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 5g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 20℃ for 360d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0128] Example 16

[0129] A method for preparing blueberry wine by treating blueberry fruits with melatonin.

[0130] Fresh blueberry fruits with a sugar content of 12% were taken, and were immersed in a 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to melatonin solution was 2:5.

[0131] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 20° C. and a relative humidity of 70%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0132] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0133] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 25℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 5g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0134] Comparative Example 1

[0135] A method for preparing blueberry wine by treating blueberry fruits with deionized water.

[0136] Fresh blueberry fruits with a sugar content of 12% were taken, and were soaked in deionized water for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruits to deionized water was 2:5.

[0137] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 20° C. and a relative humidity of 70%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0138] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0139] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 25℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0140] Comparative Example 2

[0141] A method for preparing blueberry wine by fumigating blueberry fruits with 1-methylcyclopropene.

[0142] Fresh blueberry fruits with a sugar content of 12% were fumigated with 1 μL / L 1-methylcyclopropene for 24 h.

[0143] The blueberry fruits fumigated with 1-methylcyclopropene are subjected to post-harvest dehydration treatment at a temperature of 20° C. and a relative humidity of 70%. The dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0144] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0145] The effective number of live bacteria added to blueberry pulp is 1×10 6CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 25℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0146] Comparative Example 3

[0147] A method for preparing blueberry wine by treating blueberry fruits with melatonin+1-methylcyclopropene.

[0148] Fresh blueberry fruits with a sugar content of 12% were taken, and after being fumigated with 1 μL / L 1-methylcyclopropene for 24 hours, they were immersed in 250 μmol / L melatonin solution for 5 minutes, and then air-dried at room temperature until the surface was dry to obtain air-dried blueberries; wherein the mass ratio of blueberry fruit to melatonin+1-methylcyclopropene was 2:5.

[0149] The air-dried blueberries are subjected to post-harvest dehydration treatment at a temperature of 20° C. and a relative humidity of 70%, and the dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0150] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0151] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 25℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0152] Comparative Example 4

[0153] A method for preparing blueberry wine by dehydrating blueberry fruits.

[0154] Fresh blueberry fruits with a sugar content of 12% are taken and dehydrated at a temperature of 20° C. and a relative humidity of 70%. The dehydrated blueberry fruits with a weight loss of 30% are crushed to obtain blueberry mash.

[0155] Potassium metabisulfite was added to the blueberry mash, stirred evenly, and pectinase was added after standing for 2 hours. The mixture was hydrolyzed at 25°C in the dark for 24 hours to obtain a hydrolyzed material. White sugar was added to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and the sugar content was calculated as refracted sugar to obtain blueberry pulp. The mass ratio of blueberry mash, potassium metabisulfite and pectinase was 100000:9:5.

[0156] The effective number of live bacteria added to blueberry pulp is 1×10 6 CFU / mL of brewer's yeast was activated at 38℃ for 20min, stirred evenly, and fermented for 18 days at 25℃. During the fermentation period, the wine cap was pressed twice a day and the total sugar content was tested. The skin residue was separated and the sake was collected. The total sugar content in the sake was 4g / L. Potassium pyrosulfite was added, stirred evenly, and aged at 16℃ for 180d to obtain the finished blueberry wine; the mass ratio of blueberry pulp, brewer's yeast, and potassium pyrosulfite was 20000:8:1.

[0157] Comparative Example 5

[0158] A method for preparing blueberry wine by directly crushing blueberry fruits.

[0159] Blueberry wine was prepared according to the method of Example 1, except that fresh blueberry fruits with a sugar content of 12% were directly crushed to obtain blueberry mash for brewing blueberry wine.

[0160] The blueberry fruits and blueberry wines prepared in Example 16, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 and Comparative Example 5 were selected for testing, and the following data were obtained:

[0161] Table 1 Effect of moderate post-harvest dehydration and drying treatment on aroma active components in blueberry wine in the present invention

[0162]

[0163]

[0164] Note: ND means not detected. The aroma component can still be perceived after being diluted 1024 times. Generally, the dilution factor is not further determined and is expressed as greater than 1024.

[0165] Table 2 Decay rate and terpene content of blueberry fruit in the present invention

[0166]

[0167]

[0168] Note: Different letters a, b, c, d, e in the same row of the table indicate significant differences between the groups, p<0.05; "Tr" means not detected; "-" means no such item.

[0169] Terpenes are the main components that contribute to the "floral and fruity aroma" of fruit wine. The terpene flavor substances and their precursors in blueberry fruits are extracted, hydrolyzed, and released during the fermentation process, and are an important source of the "floral and fruity aroma" of blueberry wine. It is generally believed that the higher the content of terpenes in the berries, the stronger the "floral and fruity aroma" of the fruit wine, and the higher the flavor quality of the fruit wine. The aroma-active components in the blueberry wine brewed from blueberry fruits that were moderately dehydrated and dried after harvest in Comparative Example 4 and the blueberry wine brewed from fresh blueberries in Comparative Example 1 were analyzed by gas chromatography-olfaction-mass spectrometry, abbreviated as GC-O-MS, confirming that the terpenes in blueberry wine mainly contribute to the "floral and fruity aroma", as shown in Table 1.

[0170] Melatonin is not only a strong antioxidant that can control the occurrence of diseases and decay of fruits and vegetables after harvest, but also a plant hormone signal molecule that can participate in regulating various physiological processes in fruits and vegetables after harvest. In the present invention, as shown in Table 2, compared with the blueberry fruit of Comparative Example 5, the blueberry fruit of Comparative Example 4 only moderately dehydrated and dried, and the blueberry fruit of Comparative Example 1 using pure water immersion coupled with moderate dehydration and drying, the decay rate of blueberry fruit after melatonin treatment in Example 16 was significantly reduced, and the content of most terpenes and total terpenes was significantly increased, which can enhance the "flower and fruit aroma" of the blueberry wine brewed therefrom. 1-Methylcyclopropene, as an ethylene receptor inhibitor, is also commonly used in fruit preservation, which can reduce the decay rate of fruit during storage. In the present invention, compared with Comparative Example 5, the use of 1-methylcyclopropene coupled with post-harvest dehydration and drying in Comparative Example 2 also significantly reduced the decay rate of blueberry fruit. However, compared with Comparative Example 4 only moderately dehydrated and dried, the terpene content of blueberry fruit in Comparative Example 2 decreased significantly. In Comparative Example 3, the total terpene content of blueberry fruits treated with postharvest melatonin + 1-methylcyclopropene coupled with postharvest dehydration and drying was significantly higher than that of Comparative Example 4, further proving that postharvest melatonin treatment has the effect of increasing the terpene content in blueberry fruits. Figure 1 As shown, compared with the blueberry wine brewed by blueberry fruits of comparative example 5, comparative example 4 only moderate dehydration and drying treatment, and comparative example 1 using pure water immersion coupled with moderate dehydration and drying treatment of blueberry fruits, the blueberry wine brewed by blueberry fruits treated with post-harvest melatonin in Example 16 coupled with moderate dehydration and drying treatment has stronger blueberry aroma, floral aroma, fruity aroma, melon aroma, and honey aroma, and a higher overall aroma score. In summary, post-harvest melatonin treatment coupled with moderate dehydration and drying treatment can not only reduce the decay rate of blueberry fruits, but also increase the content of terpenes, thereby enhancing the floral and fruity aroma of brewed blueberry wine.

[0171] Furthermore, the present invention tested the total terpene content of Examples 1 to 15, which were all between 877.28 and 917.28, higher than Comparative Examples 1 to 5, and the melatonin treatment of Examples 1 to 15 coupled with moderate dehydration and drying treatment reduced the decay rate of blueberry fruit.

[0172] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0173] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing blueberry wine by treating blueberry fruits with melatonin, characterized in that: The following steps are involved: Take blueberry fruits with a sugar content of ≥12%, soak them in a melatonin solution, and air-dry them until the surface is dry to obtain air-dried blueberries; wherein the concentration of the melatonin solution is 200 μmol / L to 250 μmol / L, and the mass ratio of blueberry fruits to the melatonin solution is 1.5 to 2.5:5; The air-dried blueberries are dehydrated and crushed to obtain blueberry mash; Add potassium pyrosulfite to the blueberry mash and stir evenly, let it stand for 2 h to 3 h, add pectinase to hydrolyze to obtain a hydrolyzed material, add white sugar to adjust the mass percentage of soluble solids in the hydrolyzed material to 22%, and obtain blueberry pulp, wherein the mass ratio of blueberry mash, potassium pyrosulfite and pectinase is 100000:8-10:4-6; The method comprises adding brewer's yeast to blueberry pulp for alcohol fermentation, separating skin residue, collecting sake, adding potassium pyrosulfite, and preparing blueberry finished wine after aging, wherein the mass ratio of blueberry pulp, brewer's yeast and potassium pyrosulfite is 20000:7-9:0.5-1.

5.

2. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The blueberry fruit is immersed in the melatonin solution for 5 to 8 minutes.

3. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The environmental temperature for the dehydration treatment of the blueberry fruit is 15° C. to 25° C., and the relative humidity is 60% to 80%.

4. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The blueberry fruit is crushed when the weight loss after dehydration is 20% to 30%.

5. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The hydrolysis temperature of adding pectinase is 25°C to 30°C, and the hydrolysis time is 24h to 26h.

6. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The alcohol fermentation temperature is 22° C. to 28° C., and the fermentation time is 17 days to 19 days.

7. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The total sugar content in the sake is 4g / L-5g / L.

8. The method for preparing blueberry wine by treating blueberry fruits with melatonin as claimed in claim 1, characterized in that: The aging temperature is 16° C. to 20° C., and the aging time is 180 days to 360 days.

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