Strawberry wine and its brewing method

Abstract

The application discloses a kind of strawberry wine and its brewing method, adopt first Angelus yeast SY after Angelus yeast RW fermentation after the strawberry wine aroma compound content of aging is ester > alcohol > acid > other > terpene class.SY+RW fermentation of strawberry wine aroma compound content is ester > alcohol > other > acid > terpene class, it is rich in the complexity of wine aroma, give fruit wine more elegant and unique aroma;Wherein, in the fermentation of Angelus yeast SY, the highest OAV value of isoamyl acetate is given, and the main fermentation stage of wine body presents the rich banana aroma;In the fermentation stage of Angelus yeast RW, the content of ester is more, wherein the highest OAV value of ethyl decanoate and isoamyl acetate is given, and the rich pineapple, banana aroma of post-fermentation stage of wine body is given;With the progress of fermentation, the highest OAV value of ethyl cinnamate and phenylethanol is reached, and the rose flower fragrance and sweet amber paste fragrance of strawberry wine aging stage are given, and accompanied by the original aroma of strawberry fruit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brewing, in particular to a strawberry wine and a brewing method thereof. BACKGROUND

[0002] Strawberry is rich in nutrition, delicious in taste, tender in appearance, juicy in pulp, and sweet and sour in taste, and has strong aroma, so it is known as the queen of fruits. Fruit wine refers to a low-alcohol beverage brewed by using fruits other than grapes as raw materials through fermentation process. At present, the production process of strawberry wine in China is to use fresh strawberries as the main raw material to brew. However, the related products on the market are mostly added with essence to increase the unique aroma of strawberry wine, which does not meet the consumer's demand for "zero addition".

[0003] Patent application No. CN95115653.5 discloses a fermented strawberry wine and a production method thereof. The fermented strawberry wine is prepared by using strawberries as raw materials, through natural fermentation and secondary open fermentation with yeast liquid, juice separation, fermentation and aging of the juice to obtain a fermented wine with an alcohol degree of 7-15% v / v, total acid of 0.45-0.75 g / 100 ml, and sugar content of 5-13 g / 100 ml; and fermentation and distillation of the pulp to obtain a strawberry brandy with an alcohol degree of 38-41% v / v, total acid of 0.2-0.4 g / 100 ml, and total ester of 0.075-0.085 g / 100 ml. The present application enriches the strawberry products, retains the aroma and nutrients of strawberries, is beneficial to human body absorption, has a fragrant, rich aroma, and shows the color, aroma and taste of wine. However, the method uses a kind of yeast for twice brewing, although it claims to increase the aroma of strawberry wine, but it cannot quantitatively analyze the content of aroma ester, and cannot verify the effect of increasing aroma. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a strawberry wine and a brewing method thereof.

[0005] To achieve the above-mentioned purposes, the present application is implemented according to the following technical solutions:

[0006] The first object of the present application is to provide a brewing method of strawberry wine, comprising the following steps:

[0007] S1, thawing the frozen strawberry fruits, adding 0.5 g / kg pectinase for enzymolysis, and enzymolysis for 4 h, filtering to obtain a strawberry fruit liquid, and adjusting the brix of the strawberry fruit liquid to 15-20°Brix, and standing for 4 h to obtain a fermentation-ready strawberry fruit liquid;

[0008] S2, sterilizing the fermentation-ready strawberry fruit liquid;

[0009] S3, 0.25g / kg of activated Angel yeast SY is added to the sterilized strawberry fruit liquid to be fermented, and fermentation is carried out for 48h;

[0010] S4, 0.25g / kg of activated Angel yeast RW equivalent to the activated Angel yeast SY is further added to continue fermentation for 7d, then filtration is carried out, the filtrate is taken to be fermented for 15d again, after filtration, the filtrate is filled into a sealed container which has been sterilized to be aged, and a strawberry wine is obtained.

[0011] Further, in the step S1, white granulated sugar is used to adjust the sugar degree of the strawberry fruit liquid.

[0012] Further, in the step S2, potassium metabisulfite is added to the strawberry fruit liquid to be fermented to be sterilized.

[0013] Further, the activation of the Angel yeast RW and the Angel yeast SY is carried out by using a 5% sugar solution with a concentration of 10 times the weight of the Angel yeast RW or the Angel yeast SY, and the activation temperature is 32℃.

[0014] A second object of the present application is to provide a strawberry wine prepared by the above method.

[0015] Compared with the prior art, the strawberry wine after fermentation and aging by the Angel yeast SY and then the Angel yeast RW has the content of aroma compounds in the order of esters>alcohols>acids>other compounds>terpenes. The content of aroma compounds of the strawberry wine fermented by the Angel yeast SY and the Angel yeast RW is in the order of esters>alcohols>other compounds>acids>terpenes, which enriches the complexity of the aroma of the wine and gives the fruit wine more elegant and unique aroma; in the Angel yeast SY fermentation, the OAV value of isoamyl acetate is the highest, which gives the wine body in the main fermentation stage a rich banana aroma; in the Angel yeast RW fermentation stage, the content of esters increases, and the OAV values of ethyl decanoate and isoamyl acetate are the highest, which gives the wine body in the post-fermentation stage a rich pineapple and banana aroma; with the fermentation, the OAV values of ethyl cinnamate and phenethyl alcohol reach the highest, which gives the strawberry wine in the aging stage a rose flower aroma and sweet amber cream aroma, and the original aroma of the strawberry fruit. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a comparison of the content of aroma substances in the main fermentation stage of the strawberry wine fermented by the Angel yeast SY and the Angel yeast RW in different ways.

[0017] Figure 2 It is a percentage of aroma substances in the main fermentation stage of the strawberry wine fermented by the Angel yeast SY and the Angel yeast RW in different ways.

[0018] Figure 3 It is a comparison of the content of aroma substances in the post-fermentation stage of the strawberry wine fermented by the Angel yeast SY and the Angel yeast RW in different ways.

[0019] Figure 4 Comparison of the percentage of aroma substances in the strawberry wine after fermentation by SY and RW in different ways.

[0020] Figure 5 Comparison of the content of aroma substance species in the strawberry wine aged by SY and RW mixed fermentation.

[0021] Figure 6 The percentage of aroma substance content in the strawberry wine aged by SY and RW mixed fermentation. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with examples. The specific examples described herein are only used to explain the present application and do not limit the present application.

[0023] Example 1

[0024] The strawberry wine was fermented by Angel yeast SY and then Angel yeast RW (denoted as SY-RW), and the specific operation was as follows:

[0025] S1, the frozen strawberry fruit was thawed, 0.5 g / kg pectinase was added for enzymolysis, and the enzymolysis was carried out for 4 h, the filtrate was obtained by filtering, and the sugar degree of the strawberry fruit liquid was adjusted to 15°Brix-20°Brix by white granulated sugar, and the strawberry fruit liquid was obtained after standing for 4 h;

[0026] S2, potassium metabisulfite was added to the strawberry fruit liquid to be fermented for sterilization;

[0027] S3, 0.25 g / kg of Angel yeast SY activated (activated by using 10 times the weight of the activated Angel yeast SY with a sugar solution of 5% concentration, and the activation temperature was 32℃) was added to the sterilized strawberry fruit liquid to be fermented for fermentation for 48 h;

[0028] S4, 0.25 g / kg of Angel yeast RW activated (activated by using 10 times the weight of the activated Angel yeast RW with a sugar solution of 5% concentration, and the activation temperature was 32℃) was further added for continuous fermentation for 7 d, and then the filtrate was obtained by filtering, and the filtrate was further fermented for 15 d, and then the filtrate was filled into a sealed container which had been sterilized to be aged, and the strawberry wine was obtained.

[0029] Comparative Example 1

[0030] The strawberry wine was fermented by Angel yeast RW and then Angel yeast SY (denoted as RW-SY), and the specific operation was as follows:

[0031] S1, the frozen strawberry fruit is thawed, 0.5 g / kg pectinase is added for enzymolysis, the enzymolysis is carried out for 4 h, the filtrate is obtained by filtering to obtain strawberry fruit liquid, and white granulated sugar is used to adjust the brix of the strawberry fruit liquid to 15°Brix-20°Brix, and the strawberry fruit liquid is rested for 4 h to obtain the strawberry fruit liquid to be fermented;

[0032] S2, potassium metabisulfite is added to the strawberry fruit liquid to be fermented to sterilize;

[0033] S3, 0.25 g / kg of activated (activated by using 10 times the weight of Angel yeast SY of a 5% sugar solution, and the activation temperature is 32 DEG C) Angel yeast RW is added to the sterilized strawberry fruit liquid to be fermented to ferment for 48 h;

[0034] S4, 0.25 g / kg of activated (activated by using 10 times the weight of Angel yeast RW of a 5% sugar solution, and the activation temperature is 32 DEG C) Angel yeast SY is further added to continue to ferment for 7 d, then filtering is carried out, the filtrate is taken to further ferment for 15 d, and after filtering, the filtrate is filled into a sealed container which has been sterilized to perform aging, and the strawberry wine is obtained.

[0035] Comparative Example 2

[0036] Angel yeast RW and Angel yeast SY are mixed to ferment (denoted as SY+RW) to brew the strawberry wine, and the specific operation is as follows:

[0037] S1, the frozen strawberry fruit is thawed, 0.5 g / kg pectinase is added for enzymolysis, the enzymolysis is carried out for 4 h, the filtrate is obtained by filtering to obtain strawberry fruit liquid, and white granulated sugar is used to adjust the brix of the strawberry fruit liquid to 15°Brix-20°Brix, and the strawberry fruit liquid is rested for 4 h to obtain the strawberry fruit liquid to be fermented;

[0038] S2, potassium metabisulfite is added to the strawberry fruit liquid to be fermented to sterilize;

[0039] S3, 0.25 g / kg of activated (activated by using 10 times the weight of Angel yeast SY of a 5% sugar solution, and the activation temperature is 32 DEG C) Angel yeast RW and 0.25 g / kg of activated (activated by using 10 times the weight of Angel yeast RW of a 5% sugar solution, and the activation temperature is 32 DEG C) Angel yeast SY are added to the sterilized strawberry fruit liquid to be fermented to ferment for 48 h;

[0040] S4, then filtering is carried out, the filtrate is taken to further ferment for 15 d, and after filtering, the filtrate is filled into a sealed container which has been sterilized to perform aging, and the strawberry wine is obtained.

[0041] Comparative Example 3

[0042] Angel yeast is used to ferment (denoted as RW) to brew the strawberry wine, and the specific operation is as follows:

[0043] S1, the frozen strawberry fruit is thawed, 0.5 g / kg pectinase is added for enzymolysis, the enzymolysis is carried out for 4 h, the filtrate is obtained by filtering, the strawberry fruit juice is obtained, and the brix of the strawberry fruit juice is adjusted to 15°Brix-20°Brix by white granulated sugar, and the strawberry fruit juice is obtained after standing for 4 h;

[0044] S2, potassium metabisulfite is added to the fermentation-ready strawberry fruit juice for sterilization;

[0045] S3, 0.25 g / kg of activated Angel yeast RW (activated by using 10 times the weight of the concentration of 5% sugar solution of Angel yeast SY, and the activation temperature is 32℃) is added to the fermentation-ready strawberry fruit juice after sterilization for fermentation for 48 h;

[0046] S4, then filtering, taking the filtrate, re-fermenting for 15 d, and then filtering, the filtrate is filled into a sealed container after sterilization is completed, and the filtrate is aged, and the strawberry wine is obtained.

[0047] Comparative Example 4

[0048] Angel yeast SY mixed fermentation (denoted as SY) is used to brew strawberry wine, and the specific operation is as follows:

[0049] S1, the frozen strawberry fruit is thawed, 0.5 g / kg pectinase is added for enzymolysis, the enzymolysis is carried out for 4 h, the filtrate is obtained by filtering, the strawberry fruit juice is obtained, and the brix of the strawberry fruit juice is adjusted to 15°Brix-20°Brix by white granulated sugar, and the strawberry fruit juice is obtained after standing for 4 h;

[0050] S2, potassium metabisulfite is added to the fermentation-ready strawberry fruit juice for sterilization;

[0051] S3, 0.25 g / kg of activated Angel yeast SY is added to the fermentation-ready strawberry fruit juice after sterilization for fermentation for 48 h;

[0052] S4, then filtering, taking the filtrate, re-fermenting for 15 d, and then filtering, the filtrate is filled into a sealed container after sterilization is completed, and the filtrate is aged, and the strawberry wine is obtained.

[0053] The physicochemical indexes of the fermented strawberry wine in the above example 1, comparative example 1 and comparative example 2 are shown in table 1.

[0054] Table 1

[0055]

[0056] From Table 1, it can be seen that the three kinds of fermented strawberry wine prepared by the fermentation meet the agricultural standards of green food wine. Among them, the alcohol content of SY+RW strawberry wine after aging is the highest, which is 10.15%vol, but it is lower than that of SY and RW single yeast fermentation. It may be due to the inhibition of alcohol production capacity between the two yeasts, resulting in lower alcohol content and slower fermentation rate. The soluble solids content is slightly lower than that of single yeast fermentation, the lowest is SY-RW fermentation method for 4.61, which is 0.89 lower than the lowest single yeast L. The total acid values of the three fermentation methods are not much different, but they are all less than the single yeast fermentation, which is also consistent with the mixed fermentation consuming more acid and alcohol to produce esters. Although the three kinds of strawberry wine are fermented by the same yeast strain, there are differences in the fermentation sequence, so there are differences between the physicochemical indexes of the finished wine.

[0057] (1)SY and RW mixed yeast fermentation strawberry wine main fermentation stage aroma difference

[0058] The types and contents of aroma compounds in SY and RW mixed yeast fermentation strawberry wine main fermentation stage are shown in Table 1. Figure 1 、 Figure 2 The content of aroma compounds of SY-RW fermented strawberry wine is esters>alcohols>others>terpenes>acids. The content of aroma compounds of SY+RW fermented strawberry wine is esters>alcohols>terpenes>others>acids, and the content of aroma compounds of RW-SY fermented strawberry wine is alcohols>esters>others>terpenes>acids. Among them, the content of alcohol aroma compounds of RW-SY fermented strawberry wine is far higher than that of the other four fermentations, accounting for 41% of the total alcohol content, and the content of ester, acid, terpene and other class of aroma compounds of SY+RW fermented strawberry wine is far higher than that of other fermented strawberry wine. Mixed fermentation is generally greater than single yeast fermentation in the content of esters, acids, terpenes and other classes, especially the content of ester, terpene and other class of aroma substances is significantly increased. Except for RW-SY, the content of alcohol compounds in single yeast main fermentation stage is better than that of mixed fermentation, which may be due to the mutual repulsion of the two yeasts, affecting the fermentation rate and alcohol production capacity, resulting in lower content of higher alcohols than single yeast, but the content and types of ester compounds are far higher than single yeast.

[0059] The composition and content of volatile compounds in the main fermentation stage of two different yeast mixed fermentation strawberry wine were detected by GC-MS, as shown in Table 2.

[0060] Table 2

[0061]

[0062]

[0063]

[0064] All samples were in triplicate, and the data in the table were expressed as the mean value.

[0065] As shown in Table 2, 39 volatile substances were detected in the main fermentation stage of the SY-RW fermentation method, including 12 ester substances, 3 alcohol substances, 8 acid substances, 4 terpene substances, and 3 other substances. The content of ethyl octanoate, ethyl decanoate, ethyl laurate, and isoamyl alcohol exceeded 10,000 μg / L, the content of isoamyl acetate, ethyl myristate, ethyl linoleate, and phenylethanol exceeded 5,000 μg / L, and the eight substances were the main aroma components during the main fermentation stage of the SY-RW fermentation method. The aroma substances with an OAV value greater than 1 were isoamyl acetate, ethyl octanoate, phenylethyl acetate, ethyl decanoate, ethyl cinnamate, ethyl laurate, ethyl linoleate, isoamyl alcohol, octanoic acid, decanoic acid, styrene, and 4-methoxy-2,5-dimethyl-3(2H)-furanone, and the twelve aroma substances were the key aroma substances in the main fermentation stage of the SY-RW fermentation method. The isoamyl acetate had the highest OAV value, and the whole wine body in the main fermentation stage presented a rich banana aroma.

[0066] In the main fermentation stage, 50 aroma substances were detected in SY+RW fermentation mode, including 21 ester substances, 7 alcohol substances, 4 acid substances, 12 terpene substances and 6 other substances. Among them, isopropyl formate, sec-amyl acetate, isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, isoamyl alcohol, phenyl succinic acid, styrene, 3-furfuryl formaldehyde and butyraldehyde diethyl acetal had a content of more than 10,000 μg / L, ethyl laurate, active amyl alcohol, isopropyl alcohol, suohexiang alcohol and cyclooctatetraene had a content of more than 5,000 μg / L, and these 16 substances were the main aroma components in the main fermentation stage of RW+SY fermentation mode. Among them, isopropyl formate presented fruity, ether and pear-like sweet taste, 3-furfuryl formaldehyde was one of the characteristic substances of Maotai-flavor liquor, acetaldehyde and ethanol condensed to form acetal, which presented a clear aroma and thick taste. The OAV values of the aroma substances were greater than 1, including ethyl butyrate, isoamyl acetate, ethyl hexanoate, ethyl octanoate, phenethyl acetate, 3-phenylpropyl acetate, ethyl decanoate, isoamyl octanoate, ethyl laurate, ethyl palmitate, isoamyl alcohol, active amyl alcohol, styrene, pinene, butyraldehyde diethyl acetal, 2-pentyl furan and 4-methoxy-2,5-dimethyl-3(2H)-furanone, and these 17 aroma substances were the key aroma substances of the liquor. Among them, ethyl hexanoate had the largest OAV value and was the main aroma smell, which made the whole liquor body present apple and pear fruit aroma and long aftertaste. Ethyl hexanoate was not detected in the other two fermentation modes, indicating that ethyl hexanoate was a characteristic aroma in the main fermentation stage of mixed simultaneous fermentation. In the main fermentation stage of RW-SY fermentation mode, 32 volatile substances were detected, including 9 ester substances, 8 alcohol substances, 6 acid substances, 7 terpene substances and 2 other substances. Among them, the aroma components of strawberry wine, such as isoamyl acetate, ethyl octanoate, phenethyl acetate, 3-phenylpropyl acetate, ethyl decanoate, ethyl laurate, ethyl myristate and isoamyl alcohol, were included. Among them, the contents of ethyl decanoate, ethyl laurate, isoamyl alcohol and active amyl alcohol were more than 10,000 μg / L, the contents of ethyl octanoate, acetic acid and styrene were more than 5,000 μg / L, and these 7 substances were the main aroma components in the main fermentation stage of RW-SY fermentation mode. The OAV values of the aroma substances were greater than 1, including isoamyl acetate, ethyl octanoate, phenethyl acetate, ethyl decanoate, ethyl cinnamate, ethyl laurate, isoamyl alcohol, octanoic acid, styrene and 4-methoxy-2,5-dimethyl-3(2H)-furanone. These 10 substances were the key aroma substances in the main fermentation stage of RW-SY fermentation mode. Among them, ethyl decanoate and isoamyl acetate had the highest OAV value, which gave the liquor body a rich pineapple and banana-like aroma in the main fermentation stage.The highest OAV value of aroma substances in the main fermentation stage of mixed simultaneous fermentation was ethyl hexanoate, which had strong apple and pear aroma, sweet taste and refreshing taste. However, ethyl hexanoate was not detected in sequential fermentation. The types and contents of esters, terpenes and other substances in mixed simultaneous fermentation were higher than those in mixed sequential fermentation and single yeast fermentation. The content of ester substances in SY-RW fermentation was 102697.9 μg / L, which was higher than that in RW-SY fermentation. The content of the two key aroma components, isoamyl acetate, in SY-RW fermentation was also higher than that in RW-SY fermentation. Therefore, the aroma performance of SY-RW fermentation was slightly better than that of RW-SY fermentation. Therefore, the aroma performance of the main fermentation stage was RW+SY>SY-RW>RW-SY>RW>SY.

[0067] (2) Aroma research of strawberry wine fermented by SY and RW yeasts in the post-fermentation stage

[0068] The types and contents of aroma compounds in strawberry wine fermented by SY and RW yeasts in the post-fermentation stage are shown in Table 2. Figure 3 、 Figure 4 The content of aroma compounds in strawberry wine fermented by SY-RW sequential fermentation was esters>alcohols>acids>others>terpenes. The content of aroma compounds in strawberry wine fermented by SY+RW was esters>alcohols>others>acids>terpenes. The content of aroma compounds in strawberry wine fermented by RW-SY was alcohols>esters>acids>terpenes>others. The relative contents of esters, acids and other aroma compounds in strawberry wine fermented by SY-RW sequential fermentation were higher than those in the other four fermentations. Although the content of other aroma compounds was not high, they were easily smelled due to their low aroma threshold, which enriched the complexity of wine aroma and gave the wine more elegant and unique aroma. The relative contents of alcohols, acids and terpenes in strawberry wine fermented by SY and RW single yeasts in the post-fermentation stage were higher than those in RW-SY and SY+RW mixed fermentations, but the ester content was lower than that in SY-RW and SY+RW mixed fermentations, indicating that the fruit aroma intensity was lower than that in mixed fermentation. The content of ester substances in SY-RW fermentation increased from 102697.9 μg / L to 175281.1 μg / L, and the content of alcohol substances increased from 93371.48 μg / L to 142447.9 μg / L, while the contents of acid and terpene substances decreased. This may be due to the strong ability of Saccharomyces cerevisiae to produce higher alcohols. The mixed fermentation of double Saccharomyces cerevisiae produced more higher alcohols, and alcohols and acids generated esters through esterification, which not only increased the content of esters, but also consumed the content of acids, resulting in a decrease in the content of acid substances. The main acid substances in strawberry wine were acetic acid and octanoic acid, which could give the wine cheese and fat aroma when present in small amounts, but high content would have a negative impact on the aroma and quality of the wine. Therefore, mixed fermentation had a certain effect on reducing the negative impact of acid substances.

[0069] The composition and content of volatile compounds in the post-fermentation stage of strawberry wine fermented by two different yeast mixtures were detected by GC-MS, as shown in Table 3.

[0070] Table 3

[0071]

[0072]

[0073]

[0074] All samples were in triplicate, and the data in the table were represented as the average value.

[0075] As shown in Table 3, 39 volatile substances were detected in the post-fermentation stage of SY-RW fermentation, including 17 ester substances, 7 alcohol substances, 7 acid substances, 2 terpene substances, and 5 other substances. Among them, the content of ethyl octanoate, ethyl decanoate, ethyl laurate, ethyl myristate, isoamyl alcohol, n-pentanol, and 2,3-butanediol exceeded 10000 μg / L, the content of ethyl linoleate and valeric acid exceeded 5000 μg / L, and these 9 substances were the main aroma components during the main fermentation of SY-RW fermentation. Among them, 2,3-butanediol had no aroma, sweet, alcohol, relatively thick, and had a refreshing taste. The aroma substances with OVA value greater than 1 were isoamyl acetate, ethyl octanoate, phenethyl acetate, ethyl nonanoate, 3-phenylpropionic acid ethyl ester, ethyl decanoate, ethyl laurate, ethyl linoleate, isoamyl alcohol, phenethyl alcohol, valeric acid, 3-hydroxy-2-butanone, and 4-methoxy-2,5-dimethyl-3(2H)-furanone. These 13 aroma substances were the key aroma substances in the post-fermentation stage of SY-RW, and among them, ethyl decanoate and isoamyl acetate had the highest OAV value, making the whole wine body in the post-fermentation stage present a rich pineapple and banana aroma.

[0076] 26 kinds of aroma substances were detected in the post-fermentation stage of SY+RW fermentation mode, including 11 kinds of esters, 7 kinds of alcohols, 2 kinds of acids, 5 kinds of terpenes and 1 kind of other substances. Among them, isoamyl acetate, ethyl hexanoate, ethyl decanoate, isoamyl alcohol, spin alcohol and phenyl succinic acid content exceeded 10000 μg / L, ethyl octanoate, ethyl laurate, methyl benzyl alcohol, d-terpinene and basilene content exceeded 5000 μg / L. These 11 substances were the main aroma components during the post-fermentation stage of RW+SY sequential fermentation. Among them, 2-furfuryl acetate had the aroma of green apple and kiwi, and basilene had the aroma of grass and flowers with the scent of orange blossom oil. The aroma substances with OAV value greater than 1 were ethyl butyrate, ethyl hexanoate, methyl octanoate, ethyl octanoate, ethyl decanoate, ethyl laurate, isoamyl alcohol, phenylethyl alcohol, terpineol and 4-methoxy-2,5-dimethyl-3(2H)-furanone. These 10 aroma substances were the key aroma substances in the post-fermentation stage of the wine. Among them, ethyl hexanoate had the largest OAV value and was the main aroma smell, making the whole wine body present the aroma of fruits such as apple and pear.

[0077] 24 kinds of volatile substances were detected in the post-fermentation stage of RW-SY fermentation mode, including 11 kinds of esters, 5 kinds of alcohols, 3 kinds of acids, 2 kinds of terpenes and 2 kinds of other substances. Among them, ethyl undecanoate and isoamyl alcohol content exceeded 10000 μg / L, ethyl octanoate, ethyl decanoate, ethyl laurate and 2,3-butanediol content exceeded 5000 μg / L. These 6 substances were the main aroma components during the post-fermentation stage of RW-SY sequential fermentation. Among them, ethyl undecanoate had the aroma of coconut. The aroma substances with OAV value greater than 1 were ethyl lactate, ethyl octanoate, phenyl ethyl acetate, ethyl 3-phenylpropionate, ethyl decanoate, ethyl cinnamate, ethyl laurate, ethyl undecanoate, isoamyl alcohol, phenylethyl alcohol, octanoic acid, styrene and 4-methoxy-2,5-dimethyl-3(2H)-furanone. These 13 substances were the key aroma substances in the post-fermentation stage of RW-SY fermentation mode. Among them, the aroma substances with the largest OAV value were ethyl decanoate and D-limonene, which gave the whole wine body the aroma of rich pineapple and lemon in the post-fermentation stage, which was different from the aroma of strawberry wine in the post-fermentation stage of SY-RW and SY+RW sequential fermentation. The three fermentation modes presented different aromas in the post-fermentation stage. Ethyl hexanoate only existed in SY+RW, isoamyl alcohol was not detected in the post-fermentation stage of SY and RW single yeast fermentation, D-limonene content in mixed fermentation was slightly higher than that in single yeast fermentation, which may be related to the formation of some esters from fatty acids in mixed fermentation. In addition, mixed fermentation may affect the content of higher alcohols, and thus affect the esterification reaction of alcohol synthesis. In summary, it is again determined that different fermentation modes of mixed yeast will affect the types and contents of aroma substances.

[0078] (3) Aroma differences of strawberry wine during aging stage by mixed fermentation of SY and RW yeasts

[0079] The types and contents of aroma compounds of strawberry wine during aging stage by mixed fermentation of SY and RW yeasts are shown in Table 2. Figure 5 、 Figure 6 The contents of aroma compounds of strawberry wine by SY-RW fermentation were esters > alcohols > acids > terpenes > other. The contents of aroma compounds of strawberry wine by SY+RW fermentation were esters > alcohols > terpenes > acids > other. The contents of aroma compounds of strawberry wine by RW-SY fermentation were alcohols > esters > terpenes > other > acids. The content of alcohols aroma compounds of strawberry wine by SY fermentation was 249469.5 μg / L, which was much higher than that of the other four fermentations. The relative content of ester aroma substances of SY-RW fermentation was higher than that of the other four fermentation methods. The content of other aroma substances of RW-SY fermentation was the highest. Therefore, it can be preliminarily judged that the mixed inoculation of the two yeasts indeed changed the aroma content of strawberry wine fermented by single yeast, especially the content of ester and alcohol aroma substances changed significantly. In the three mixed fermentation strawberry wines, the content of alcohol substances was not much different, all between 46637.19 μg / L and 55715.49 μg / L, but all less than that of single yeast fermentation, indicating that although mixed fermentation improved the content of esters, the ability to produce higher alcohols was not as good as single yeast fermentation. The content of ester volatile compounds of SY-RW fermentation changed little compared with its own post-fermentation, but the contents of alcohols, acids, and terpenes were reduced. The content of esters of SY+RW was the highest during the main fermentation, reaching 160494.2 μg / L, and then showed a downward trend, reaching the minimum of 74701.78 μg / L during the aging stage. Terpene substances were rich in the main fermentation stage of mixed fermentation, and the content decreased in the aging stage. The contents and types of acids and other substances were the least in the aging stage of strawberry wine, which was consistent with the results of aroma substance changes during the aging stage of SY and RW single fermentation.

[0080] The compositions and contents of volatile compounds of strawberry wine fermented by mixed SY and RW were detected by GC-MS, as shown in Table 4.

[0081] Table 4

[0082]

[0083]

[0084]

[0085] All samples were in triplicate, and the data in the table represent the average value.

[0086] From Table 4, it can be seen that 32 volatile substances were detected in the post-fermentation stage of SY-RW fermentation mode, including 17 ester substances, 4 alcohol substances, 5 acid substances, 2 terpene substances and 4 other substances. Among them, isoamyl formate, 2-methyl butyl acetate and phenethyl alcohol content exceeded 10000 μg / L, and ethyl decanoate content exceeded 5000 μg / L. These four substances were the main aroma components during the aging period of SY-RW sequential fermentation. Among them, isoamyl formate has mulberry flavor, 2-methyl butyl acetate has strong fruit flavor, and phenethyl alcohol has floral fragrance. The aroma substances with OAV value greater than 1 are isoamyl acetate, methyl benzoate, ethyl octanoate, ethyl benzoate, ethyl decanoate, ethyl cinnamate, n-octanol, benzene ethanol, terpineol, hexanoic acid, benzene aldehyde, 4-methoxy-2,5-dimethyl-3(2H)-furanone and acetophenone. These 13 aroma substances are the key aroma substances in the aging stage of SY-RW. Among them, ethyl cinnamate and benzene ethanol have the highest OAV value. Benzene ethanol can impart rose fragrance to fruit wine and can also cooperate with other aroma components to play a coordinating role in the aroma. Ethyl cinnamate imparts sweet amber paste fragrance to fruit wine, sweet orange and grape-like bottom notes, making the whole wine body present a rich rose fragrance and sweet amber paste fragrance during the aging stage, accompanied by the original fragrance of strawberry fruit.

[0087] In the post-fermentation stage, 27 aroma substances were detected in SY+RW fermentation mode, including 15 ester substances, 5 alcohol substances, 1 acid substance, 4 terpene substances and 2 other substances. Among them, isoamyl formate and methylbenzyl alcohol content exceeded 10000 μg / L, and ethyl decanoate and linalool content exceeded 5000 μg / L. These four substances are the main aroma components during the aging period of RW+SY sequential fermentation. Among them, linalool has a lily fragrance, and methylbenzyl alcohol has a clove, jasmine and silver white acacia flower-like aroma. The aroma substances with OAV value greater than 1 are ethyl hexanoate, ethyl octanoate, ethyl benzoate, ethyl decanoate, ethyl cinnamate, linalool and terpineol. These seven aroma substances are the key aroma substances of the wine. Among them, the OAV value of ethyl hexanoate is far greater than that of other aroma substances, which is the main aroma smell of olfactory, making the whole wine body present apple and pear fruit flavor. And in the SY and RW mixed fermentation, only ethyl hexanoate was detected in SY+RW from main fermentation to aging, and ethyl hexanoate was not detected in the other two fermentation modes, indicating that ethyl hexanoate is a typical aroma component of SY+RW, and mixed simultaneous fermentation may promote the formation of ethyl hexanoate. But because of its large content, the aroma is single, and the diversity and complexity of the aroma are lost.

[0088] 31 volatile substances were detected in the aging stage of RW-SY fermentation, including 16 ester substances, 6 alcohol substances, 1 acid substance, 3 terpene substances and 5 other substances. Among them, ethyl octanoate, linalool and methylbenzyl alcohol content exceeded 10000 μg / L, phenethyl acetate, ethyl decanoate and ethyl laurate content exceeded 5000 μg / L, and these six substances were the main aroma components during the aging stage of RW-SY sequential fermentation. The aroma substances with OAV value greater than 1 were isoamyl acetate, ethyl octanoate, ethyl phenylacetate, 3-phenylpropyl acetate, ethyl decanoate, ethyl laurate, ethyl palmitate, linalool, terpineol, citronellol, 4-methoxy-2,5-dimethyl-3(2H)-furanone, nonanal, damascenone and methyl ionone. These 14 substances were the key aroma substances in the aging stage of RW-SY fermentation, and the OAV value of linalool was the largest, which gave the wine a pleasant floral and citrus aroma in the aging stage. Linalool was not detected in the main fermentation and post-fermentation stages of mixed fermentation, but was detected only in the aging stage of SY+RW and RW-SY, which was different from the single yeast results. Only in the main fermentation and post-fermentation stages of single yeast, but not in the aging stage. This shows that mixed fermentation indeed changes the substances produced during fermentation, leading to different changes in aroma. The types and content of acid and ester substances are more in the aging stage of SY-RW, and ester substances can give the wine a fruity aroma, and appropriate amount of acid substances can give the wine a better taste and flavor. Terpene substances can mainly bring resin, rosemary, dry pepper, rose and lavender aroma, and at the same time, terpene compounds can relieve alcohol damage and regulate physiological rhythm. Under the catalysis of acid, molecular rearrangement occurs, leading to changes in the types and content of terpene compounds. The content of acid aroma substances is high in SY-RW aging, and the content of terpene substances is the lowest, which is inferred to be due to the catalytic reaction leading to low content. The content of terpene and alcohol in RW and SY mixed fermentation is lower than that in single yeast fermentation, which may be due to some reactions that hinder the generation of terpene substances. These problems need to be further studied and solved.

[0089] In summary:

[0090] The physicochemical indexes and aroma components of SY and RW yeast mixed fermentation in different fermentation modes are quite different. The strawberry wine brewed by the three fermentation methods all meet the agricultural standards of green food wine. The alcohol content of SY+RW yeast is the highest, reaching 10.15%vol, followed by SY-RW and RW-SY, reaching 9.76%vol and 9.72%vol respectively, indicating that the alcohol production capacity of mixed simultaneous fermentation is better than that of sequential fermentation, but not as good as that of single yeast fermentation. This may be due to the repulsion between the two yeasts, resulting in lower alcohol production capacity than single yeast. However, the ester production capacity of mixed fermentation is higher than that of single yeast.

[0091] The relative content of ester aroma substances of SY-RW is higher than all fermentation modes, and the ester content increases from the main fermentation stage, from 24% to 37%. The OAV value of isoamyl acetate is the highest in the main fermentation stage, which endows the wine with the banana aroma in the main fermentation stage; in the post-fermentation stage, the content of esters increases, and the OAV values of ethyl decanoate and isoamyl acetate are the highest, which endows the wine with the pineapple and banana aroma in the post-fermentation stage; with the fermentation, the OAV values of ethyl cinnamate and phenylethanol reach the highest, which endows the wine with the rose flower aroma and sweet amber cream in the aging stage, and is accompanied by the strawberry fruit aroma.

[0092] The content of ethyl caproate of SY+RW accounts for a relatively large proportion, so that the SY+RW fermentation process has a relatively single aroma effect, which is the aroma of apple and pear. The content of other substances of SY+RW in the main fermentation and post-fermentation is far greater than that of the other fermentation modes, but the content decreases sharply in the aging process, which may be due to the decrease of aldehydes and ketones in the aging process through a series of metabolisms.

[0093] The ester content of RW-SY is lower than that of the other two from the main fermentation to the aging, and the OAV values of ethyl decanoate and isoamyl acetate are the highest in the main fermentation stage, which endows the wine with the pineapple and banana aroma in the main fermentation stage. The aroma substances with the highest OAV values in the post-fermentation stage are ethyl decanoate and D-limonene, which endow the wine with the pineapple and lemon aroma in the post-fermentation stage, and the substance with the highest OAV value in the aging stage is linalool, which endows the wine with the pleasant flower and citrus aroma in the aging stage. According to the above analysis, the aroma capacity of the three fermentation modes in the aging stage is SY-RW>SY+RW>RW-SY>RW>SY.

[0094] Therefore, the strawberry wine fermented and aged by the Angel yeast SY and then the Angel yeast RW is adopted in the present application.

[0095] The technical scheme of the present application is not limited to the above specific embodiments, and any technical modification made according to the technical scheme of the present application falls within the protection scope of the present application.

Claims

1. A method for brewing strawberry wine, characterized by, The method comprises the following steps: S1. Thawing frozen strawberry fruits, adding 0.5 g / kg pectinase for enzymolysis, and then filtering to obtain a strawberry fruit liquid, and adjusting the sugar content of the strawberry fruit liquid to 15-20°Brix, and then standing for 4 h to obtain a fermentation-ready strawberry fruit liquid; S2. Sterilizing the fermentation-ready strawberry fruit liquid; S3. Adding activated 0.25 g / kg Angel yeast SY to the sterilized fermentation-ready strawberry fruit liquid for fermentation for 48 h; the activation of the SY yeast is carried out by using 10 times the weight of the SY yeast of a 5% sugar solution at an activation temperature of 32℃; S4. Adding activated 0.25 g / kg Angel yeast RW equivalent to the activated Angel yeast SY to continue fermentation for 7 d, and then filtering, taking the filtrate for fermentation for 15 d, and then filtering to obtain a strawberry wine by storing the filtered liquid in a sterilized closed container; the activation of the RW yeast is carried out by using 10 times the weight of the RW yeast of a 5% sugar solution at an activation temperature of 32℃.

2. The method of claim 1, wherein: In the step S1, white granulated sugar is used to adjust the sugar content of the strawberry fruit liquid.

3. The method of claim 1, wherein: In the step S2, potassium metabisulfite is added to the fermentation-ready strawberry fruit liquid for sterilization.

4. A strawberry wine prepared by the method according to any one of claims 1-3.

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