CN116554985B

CN116554985B - Purple waxy wheat litchi wine and preparation method thereof

Info

Publication number: CN116554985B
Application number: CN202310525631.4A
Authority: CN
Inventors: 段飞霞; 田静; 莫晓慧
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2023-05-10
Filing date: 2023-05-10
Publication date: 2024-09-10
Anticipated expiration: 2043-05-10
Also published as: CN116554985A

Abstract

The invention discloses a purple waxy wheat litchi wine and a preparation method thereof. The invention adopts cold soaking and freezing concentration treatment to obtain concentrated litchi juice; carrying out ultrasonic alcohol extraction, resin adsorption and freeze concentration treatment to obtain anthocyanin concentrated solution; extruding, puffing and saccharification to obtain purple waxy wheat enzymatic hydrolysate; mixing the obtained concentrated litchi juice, anthocyanin concentrate and purple waxy wheat enzymatic hydrolysate, adding activated yeast for fermentation, and removing pectin in the fermentation broth after fermentation to obtain the purple waxy wheat litchi wine. The purple waxy wheat litchi wine prepared by the method disclosed by the invention has the advantages that on the basis of keeping the quality of the composite fruit wine, the anthocyanin content, the alcoholicity and the wine yield in the composite fruit wine are effectively improved, the color of the wine body is enhanced, the aroma and the taste of the wine body are enriched, the methanol content is reduced to enhance the safety of the composite fruit wine, and the method has an important significance in improving the quality of the health-care litchi wine.

Description

Purple waxy wheat litchi wine and preparation method thereof

Technical Field

The invention belongs to the technical field of grain fruit wine brewing, and particularly relates to a purple waxy wheat litchi wine and a preparation method thereof.

Background

The picked fruits are easy to spoil and deteriorate, so that the edible value is lost, and great waste is caused. Through brewing, the fruit can be converted into the fruit wine with high added value and high physiological effect, so that the comprehensive utilization of fruit resources is enhanced, the economic added value of perishable fruits is improved, and the creation and income increase of fruit farmers can be promoted. The fermented fruit wine takes fresh fruits as raw materials, can retain most of nutritional ingredients in the fruits, such as polyphenol, organic acid, amino acid, multiple vitamin components and the like, and can improve cardiovascular and cerebrovascular functions, delay aging speed, inhibit fat accumulation in human bodies, promote metabolism of organisms, promote blood circulation and the like; in addition, the fruit wine has the characteristics of low alcohol content, multiple varieties, thick fruit fragrance, smooth and pleasant taste, unique color of wine body and the like, and is deeply favored by wide consumers. Fruit wine has outstanding advantages, but the disadvantages are also obvious. According to investigation, the problems raised by consumers include insufficient impact force of taste and aroma, single flavor, insufficient alcohol body and the like, and the popularity of the fruit wine in the domestic market is far less than that of white spirit under the influence of long-term drinking culture and brewing technology in China; compared with fruit wine, white wine takes grains as brewing raw materials and distiller's yeast as a fermenting agent, and has the characteristics of strong fragrance, endless aftertaste, mellow and harmonious taste and long aftertaste.

The Hejiang litchi is the crown of the Luzhou market, called as the King in fruit, and has the effects of relieving fatigue, nourishing and beautifying, along with thick pulp and pulp, crystal clear, crisp, tender, sweet, fragrant, fine and smooth, slag-melting, sugar, protein, vitamin and the like; the litchi wine is prepared from fresh litchi as a raw material by washing, draining, peeling, stoning, juicing, fermenting and clarifying, and has a tan wine body, a litchi fragrance and a bouquet, moderate sour and sweet taste, mellow and palatable taste and a unique litchi wine style. However, the fermented litchi wine has the problems of easy oxidation, easy browning, easy bacteria contamination, low alcoholicity, light taste and the like. In the traditional method brewing, pretreatment before litchi fermentation is usually controlled within 30 minutes to keep litchi fragrance and prevent nutrition loss, and sugar is added into the fermentation to improve alcohol content of wine body, and acid is added to inhibit growth of mixed bacteria and generation of volatile acid, but the quality and grade of litchi wine brewed by the method are not improved yet.

Purple waxy wheat 168 is a purple full waxy wheat variety suitable for large-scale planting and mechanical harvesting, has high yield and disease resistance, is suitable for high-altitude planting, and can be used for realizing rotation with waxy sorghum in Luzhou hilly area. While meeting the requirements of agricultural planting, the purple waxy wheat 168 accords with the characteristics of high-quality brewing raw materials because the amylopectin content of the grains is more than 98%, and the Xiaoqu wine brewed by adopting single raw grains of the purple waxy wheat 168 has the characteristics of high wine yield, short cellaring period and mellow flavor. In addition, the 168 seed coats of the purple waxy wheat are rich in anthocyanin, and have higher nutrition and ornamental value. The traditional white wine brewing process comprises the steps of raw material infiltration, cooking, saccharification, fermentation, distillation and the like, wherein anthocyanin degradation can be caused by high temperature generated by the cooking and the distillation, and a brewing method capable of retaining the anthocyanin of the purple waxy wheat 168 is needed to be found. In addition, the treatment time of the soaking and stewing process is long, the efficiency is low, the energy consumption is high, and the sewage discharge amount is large.

In summary, the method for preparing the composite fruit wine, which can maintain the quality of the fruit wine, improve the nutritive value, the alcoholicity and the wine yield of the fruit wine, strengthen the color of the wine body, enrich the aroma and the taste of the wine body and strengthen the safety, has important significance in the technical field of brewing of grain fruit wine.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the purple waxy wheat litchi wine and the preparation method thereof, which can effectively improve anthocyanin content, alcoholicity and wine yield in the composite fruit wine, enhance color of wine body, enrich fragrance and taste of the wine body and reduce methanol content to enhance safety of the composite fruit wine on the basis of keeping quality of the composite fruit wine.

The invention adopts the following technical scheme:

a preparation method of purple waxy wheat litchi wine comprises the following steps:

(1) Mixing fructus litchi pulp with water, pulping to obtain fructus litchi pulp, soaking, filtering, and freeze concentrating to obtain concentrated fructus litchi juice;

(2) Carrying out ultrasonic alcohol extraction on the purple waxy wheat, adsorbing and concentrating to obtain anthocyanin concentrated solution;

(3) Extruding and puffing the purple waxy wheat, and then adding saccharifying enzyme for enzymolysis to obtain purple waxy wheat enzymolysis liquid;

(4) Mixing the concentrated litchi juice obtained in the step (1), the anthocyanin concentrated solution obtained in the step (2) and the purple waxy wheat enzymatic hydrolysate obtained in the step (3), adding activated yeast for fermentation to obtain fermentation liquor, standing, filtering and collecting filtrate;

(5) And (3) adding a clarifying agent into the filtrate obtained in the step (4) for clarifying, standing and filtering to obtain the purple waxy wheat lychee wine.

By adopting the technical scheme, the invention has the beneficial effects that:

The purple waxy wheat litchi wine is a composite fruit grain wine prepared by mixing and fermenting concentrated litchi juice, anthocyanin concentrated solution and purple waxy wheat enzymatic hydrolysate, has high alcoholicity, high nutritive value, attractive color, three-dimensional plump taste and aroma, and effectively solves the problems of insufficient taste and aroma impact force, single flavor and low nutritional ingredients of the traditional litchi wine.

Further, the above mixing and beating is carried out at 5-10 ℃, preferably 5 ℃, and the mass ratio of litchi pulp to water is 1:1 to 2, preferably 1:1, a step of; immersing the litchi pulp for 3-5 days at 5-15 ℃, preferably 5 ℃ for 3 days; concentrating the filtered filtrate at-20 to-10 ℃, preferably-20 ℃; the crystallization rate is controlled to be 50-60%, preferably 60%, and the sugar content of the litchi juice is controlled to be 220-300 g/L, preferably 300g/L.

The beneficial effects of adopting the further technical scheme are as follows:

The fresh litchi juice is prepared by peeling, removing the seeds, immediately freezing, pulping by adding cold water, cold soaking and freezing concentration, and the whole-process low-temperature operation can inhibit the browning and oxidation of the litchi to keep the original natural flavor of the litchi, can prolong the pretreatment processing time of the litchi to facilitate industrial production, and can reduce the pollution of mixed bacteria in the production process to improve the safety of the product; meanwhile, the litchi pulp is immersed at low temperature, so that the color strength and stability of the fruit wine can be enhanced, the phenolic substance content of the fruit wine can be increased, the sensory evaluation score of the fruit wine can be improved, and the sugar content of the litchi juice before fermentation can be increased to 220-300 g/L by freezing and concentrating the filtered litchi juice so as to improve the alcoholicity of the fruit wine, thereby solving the problems of low alcoholicity, insufficient body, light taste and the like of the traditional litchi wine.

Further, the condition of the ultrasonic alcohol extraction is that the purple waxy wheat is subjected to alcohol extraction at the temperature of 40-60 ℃ according to the feed liquid ratio of 1: 3-5 adding citric acid-containing ethanol solution, carrying out ultrasonic ethanol extraction for 1-2 h, and centrifuging to collect supernatant; wherein the volume fraction of ethanol in the ethanol solution is 70-90%, and the mass fraction of citric acid is 0.5-1.5%; preferably, the ratio of the feed to the liquid is 1 at 50 ℃: adding an ethanol solution containing citric acid, carrying out ultrasonic ethanol extraction for 1h, and centrifuging to collect supernatant; wherein the volume fraction of ethanol in the ethanol solution is 90%, and the mass fraction of citric acid is 1%.

Further, in the step (2), the adsorption is that under the conditions that the pH value is 3-5 and the temperature is 25-35 ℃, resin is adopted to adsorb supernatant for 2-3 hours, ethanol solution containing citric acid is used for eluting, and desorption is carried out for 1-2 hours to obtain eluent, wherein the volume fraction of ethanol in the ethanol solution is 70-90%, and the mass fraction of citric acid is 0.5-1.5%; concentrating the eluent at 40-55 ℃ and under the pressure of 0.007-0.015 MPa for 30-60 min to obtain anthocyanin concentrated solution; preferably, adsorbing the supernatant with macroporous resin at a pH of 4 and a temperature of 30deg.C for 2h, eluting with ethanol solution containing citric acid, and desorbing for 2h to obtain eluent, wherein the volume fraction of ethanol in the ethanol solution is 90% and the mass fraction of citric acid is 1%; concentrating the eluate at 40deg.C under 0.008MPa for 40min.

The beneficial effects of adopting the further technical scheme are as follows:

Anthocyanin is easy to degrade, and anthocyanin can be extracted and reserved to the greatest extent by adopting treatments such as ultrasonic alcohol extraction, resin purification, vacuum low-temperature concentration and the like; in addition, the causal glue is insoluble in alcohol solution, and the ultra-sonic alcohol extraction method is used for treating the fine powder of the purple waxy wheat, so that the pectin in the concentrated solution of the purple waxy wheat is removed while the anthocyanin is dissolved out, thereby reducing the generation of methanol in the fruit grain wine.

Further, in the step (3), extruding and puffing are carried out on the purple waxy wheat flour with the water content of 12-25% under the conditions that the temperature is 120-180 ℃, the spiral diameter is 50-60 mm and the main shaft rotating speed is 300-500 r/min, and cooling to 60-65 ℃ after puffing; the mass fraction of the saccharifying enzyme added in the step (3) is 0.1-0.2%, and the enzymolysis time is 3-6 h; preferably, the purple waxy wheat flour with the water content of 20% is extruded and puffed at the temperature of 150 ℃, the spiral diameter of 50mm and the main shaft rotating speed of 400r/min, and is cooled to 60 ℃ after puffing; the mass fraction of the added saccharifying enzyme is 0.1 percent, and the enzymolysis time is 4 hours.

The beneficial effects of adopting the further technical scheme are as follows:

In order to promote the conversion of starch, the starch is gelatinized and saccharified by extrusion puffing and saccharifying enzyme respectively, so as to increase fermentation sugar and improve the alcoholicity and the wine yield; meanwhile, traditional cooking is replaced by extrusion puffing treatment, so that energy sources can be saved, the process is simplified, the fermentation period can be shortened, the pollution of mixed bacteria can be reduced, and the flavor of the wine body can be improved.

Further, the mass ratio of the mixture of the concentrated litchi juice, the anthocyanin concentrated solution and the purple waxy wheat enzymatic hydrolysate is 1:0.5 to 1.5:2 to 5, preferably 1:1:3, a step of; the mass percentage of the added activated yeast is 1-2%, preferably 1%; the fermentation process is that the fermentation is firstly carried out for 1 to 3 days at the temperature of 25 to 30 ℃, then the fermentation is finished when the total sugar content is 3.5 to 4.5g/L at the temperature of 15 to 18 ℃, preferably the fermentation is carried out for 2 days at the temperature of 25 ℃, and then the fermentation is finished when the total sugar content is 4g/L at the temperature of 15 ℃.

The beneficial effects of adopting the further technical scheme are as follows:

The purple waxy wheat enzymatic hydrolysate is added for mixed fermentation, and the purple waxy wheat contains a large amount of starch, so that the defect of low sugar content of litchi pulp can be overcome.

Further, in the step (4), the fermentation broth is kept still at 4-8 ℃, preferably 4 ℃, until the gel on the upper layer of the feed liquid stops increasing, and the filtration is performed by using a filter with the pore diameter of 20-80 meshes, preferably 40 meshes, and the filtrate is collected.

The beneficial effects of adopting the further technical scheme are as follows:

and partial pectin in the fermentation liquor can be removed through standing and filtering, so that the methanol content in the finished wine is reduced.

Further, the clarifying agent is pectase, chitosan and gelatin, and the mass ratio is 1:1 to 3:1, preferably 1:2:1.

Further, the clarification is to add a clarifying agent into the filtrate at a concentration of 0.5-0.6 mg/mL, preferably 0.6mg/mL, stand for 2-4 days, preferably 3 days, and filter to obtain the purple waxy wheat lychee wine.

The beneficial effects of adopting the further technical scheme are as follows:

The chitosan and the gelatin are used as clarifying agents for clarification, and the pectase is added into the clarifying agents to degrade residual pectin, so that the clarification purpose is realized and the methanol content in the finished wine is reduced.

The purple waxy wheat lychee wine is prepared by the preparation method of the purple waxy wheat lychee wine.

In summary, the beneficial effects of the invention are as follows:

According to the invention, based on the traditional litchi wine fermentation, the purple waxy wheat 168 anthocyanin concentrated solution is added for mixed fermentation, so that the defect of less anthocyanin in litchi pulp is overcome, meanwhile, the characteristic that the purple waxy wheat 168 is rich in anthocyanin is reasonably utilized, the pectin content in the purple waxy wheat 168 is low, the litchi contains a large amount of pectin, the pectin is converted into methanol after continuous high temperature fermentation, the toxic effect of the methanol on a human body is great, and the central nerve is inhibited when the content is too high, so that the retinal damage, optic atrophy, vision deterioration and even binocular blindness are caused. In fruit wine brewing, a common method for removing pectin is to add pectase, and pectase is a complex enzyme system composed of a plurality of enzymes, wherein pectase can randomly cut off ester bonds between methoxy groups and galacturonic acid in water-soluble pectin molecules to generate methanol and free hydroxyl groups, namely, methanol is inevitably generated when pectase is added to decompose pectin, and according to the characteristic that the boiling point of methanol is 64.5 ℃, the methanol in white wine or fruit wine is removed in a common cooking mode. The invention considers the retention of high anthocyanin, the method of removing methanol by high temperature steaming is not suitable, the concentrated lychee juice which is not subjected to pectase enzymolysis and the purple waxy wheat enzymolysis liquid which is subjected to extrusion puffing and saccharification treatment are mixed, and the reduction of pectin and methanol content in the fruit grain wine is realized through the operation of low-temperature fermentation of activated yeast and low-temperature standing and then filtration, because the lychee contains rich monosaccharides, the lychee can be directly used for fermenting by saccharomycetes to produce wine without decomposition of saccharifying enzyme or distiller's yeast, and the purple waxy wheat can convert starch into sugar which can be used for fermenting by yeast through extrusion puffing and saccharification treatment, and during the fermentation period, the wine can be produced by adding activated dry yeast; meanwhile, the preparation period and the mixed fermentation period of the concentrated litchi juice are both in low-temperature environments, pectin degradation is not caused by adding yeast, pectin can be coagulated and separated out in a macromolecular form after the fermentation liquid is subjected to low-temperature standing treatment, and the residual pectin is degraded by adding pectase into a clarifying agent, so that the clarifying purpose is realized.

The purple waxy wheat lychee wine is prepared by mixing and fermenting concentrated lychee juice, purple waxy wheat anthocyanin concentrate and purple waxy wheat enzymatic hydrolysate, has the advantages of high alcohol content, high nutritional value, attractive color, three-dimensional plump taste and aroma and the like, and effectively solves the problems of insufficient taste and aroma impact force, single flavor and low nutritional ingredients of the traditional lychee wine.

Drawings

FIG. 1 is a flow chart of the preparation of the purple waxy wheat lychee wine.

Detailed Description

The principles and features of the present invention are described below in connection with the following examples, which are set forth to illustrate, but are not to be construed as limiting the scope of the invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

Example 1

The embodiment provides a preparation method of purple waxy wheat litchi wine, which comprises the following steps:

(1) Selecting fresh, mature, non-spoiled and non-mildew litchi, immediately after peeling and stoning, placing litchi pulp at 5 ℃ for preservation, and then mixing all pulp and water at 5 ℃ according to the mass ratio of 1:1, mixing and pulping to obtain litchi pulp;

(2) Placing the litchi pulp obtained in the step (1) into a sealed dipping tank, dipping for 3d at 5 ℃ to obtain dipping liquid; filtering the impregnating solution, separating filtrate and filter residues, squeezing the filter residues, mixing the squeezed solution with the filtrate, standing at 10 ℃ for 24 hours, filtering again to obtain litchi stock solution, concentrating the litchi stock solution at-20 ℃ for freezing time, controlling the crystallization rate to be 60%, and obtaining litchi juice through 2 times of crystallization-filter pressing separation operation, so that the sugar content of the litchi juice is 300g/L;

(3) Crushing and sieving the purple waxy wheat into 50-mesh sieve to obtain fine purple waxy wheat powder, wherein the ratio of the feed liquid to the material liquid is 1:4 adding 90% ethanol solution containing 1% citric acid, performing ultrasonic ethanol extraction at 50deg.C for 1 hr, centrifuging at 8000r/min for 10min, and collecting supernatant;

(4) Adsorbing the supernatant obtained in the step (3) by macroporous resin, wherein the adsorption pH value is 4, the adsorption temperature is 30 ℃, the adsorption time is 2 hours, eluting by using 90% ethanol solution containing 1% citric acid, desorbing for 2 hours to obtain eluent, and concentrating the eluent at 40 ℃ and 0.008MPa for 40 minutes to obtain anthocyanin concentrated solution;

(5) Removing impurities from whole purple waxy wheat, crushing the purple waxy wheat to 40 meshes, adding water to adjust the water content of the raw material to 20%, extruding and puffing at a puffing temperature of 150 ℃ and a spiral diameter of 50mm under the condition that the main shaft rotating speed is 400r/min, then cooling the puffed raw material to 60 ℃ in a saccharification pot, and adding saccharifying enzyme with the mass of 0.1% of the raw material for enzymolysis for 4 hours to obtain enzymolysis liquid;

(6) The litchi juice obtained in the step (2), the anthocyanin concentrated solution obtained in the step (4) and the enzymolysis solution obtained in the step (5) are mixed according to the weight ratio of 1:1:3, placing the mixture in a fermentation tank, adding 1% of activated yeast by weight for fermentation, wherein the fermentation process is to ferment for 2 days at 25 ℃, then continue to ferment at 15 ℃, and end fermentation to obtain fermentation liquor when the total sugar content is 4 g/L;

(7) After fermentation is completed, keeping the fermentation liquor obtained in the step (6) at a temperature of 4 ℃ until gel on the upper layer of the feed liquor stops increasing, filtering by adopting filter cloth or a filter screen with a pore diameter of 40 meshes, and collecting filtrate;

(8) Adding a clarifying agent into the filtrate obtained in the step (7) at the concentration of 0.6mg/mL for clarification, standing for 3 days, and finely filtering by an ultrafiltration membrane to obtain the purple waxy wheat lychee wine, wherein the mass ratio of pectase, chitosan and gelatin in the mixed clarifying agent is 1:2:1.

Example 2

The present example provides a method for preparing a purple waxy wheat lychee wine, which is different from example 1 in that the soaking temperature in step (2) is 10 ℃.

Example 3

The present example provides a method for preparing a red waxy wheat lychee wine, which is different from example 1 in that in step (2), the crystallization rate is controlled to be 50% by cooling time, and the lychee juice is obtained through 2 crystallization-press filtration separation operations, so that the sugar content of the lychee juice is 280g/L.

Example 4

The embodiment provides a preparation method of purple waxy wheat litchi wine, which is different from embodiment 1 in that in the ultrasonic alcohol extraction in step (3), the ratio of feed liquid to liquid in the purple waxy wheat flour is 1:4 adding 90% ethanol solution containing 0.5% citric acid, ultrasonic extracting with ethanol at 50deg.C for 1 hr, centrifuging at 8000r/min for 10min, and collecting supernatant.

Example 5

The present example provides a method for preparing a purple waxy wheat lychee wine, which is different from example 1 in that the puffing temperature in step (5) is 120 ℃.

Comparative example 1

The difference between comparative example 1 and example 1 is that the cold dipping step is not performed in step (2), the litchi pulp obtained in step (1) is specifically filtered, the filtrate and the filter residue are separated, the filter residue is pressed and the pressed liquid is mixed with the filtrate, the mixture is kept stand for 24 hours at 10 ℃ and then filtered again to obtain litchi stock solution, the litchi stock solution is concentrated at-20 ℃ and the crystallization rate is controlled to be 60% in the freezing time, and the litchi juice is obtained through 2 crystallization-filter pressing separation operations, so that the sugar content of the litchi juice is 300g/L.

Comparative example 2

Comparative example 2 differs from example 1 in that no freeze concentration was performed in step (2), and the specific steps are: placing litchi pulp into a sealed dipping tank, dipping for 3d at 5 ℃ to obtain dipping liquid, then filtering the dipping liquid, separating filtrate and filter residues, squeezing the filter residues, mixing the squeezed liquid with the filtrate, standing for 24h at 10 ℃ and then filtering again to obtain litchi stock solution.

Comparative example 3

Comparative example 3 differs from example 1 in that in comparative example 3, only litchi juice and purple waxy wheat enzymatic hydrolysate were added during fermentation, and anthocyanin concentrate was not added.

Comparative example 4

Comparative example 4 differs from example 1in that the step (5) of comparative example 4 is different from example 1in that the specific steps of obtaining the purple waxy wheat enzymatic hydrolysate of comparative example 4 are: taking whole grains of purple waxy wheat, removing impurities, crushing the purple waxy wheat to 40 meshes, adding water to submerge the surface of grains for 5cm, moistening the grains at 30 ℃ for 12 hours, draining, transferring into a steamer, steaming the grains for 1 hour after the steamed grains are boiled, cooling the raw materials to 60 ℃ in a saccharification pot after the raw materials are steamed, and adding saccharifying enzyme with mass fraction of 0.1% for enzymolysis for 4 hours to obtain enzymolysis liquid.

Test examples

The alcohol degree, the wine yield, the methanol content and the anthocyanin content of the purple waxy wheat lychee wine prepared in examples 1-5 and comparative examples 1-4 are detected, and the method refers to a GB/T15308-2006 general analysis method for grape wine and fruit wine, and specifically comprises the following steps:

(1) Measuring the alcoholicity of the purple waxy wheat lychee wine by adopting an alcoholicity measuring method;

(2) Measuring the wine yield of the purple waxy wheat lychee wine by adopting the wine yield of the raw materials;

(3) Measuring the methanol content of the purple waxy wheat lychee wine by adopting a gas chromatography method;

(4) Determining anthocyanin content of the purple waxy wheat lychee wine by adopting a spectrophotometry;

The test results are shown in Table 1:

Table 1 physicochemical data of the preparation of the purple waxy wheat lychee wine of examples 1 to 5 and comparative examples 1 to 4

As can be seen from table 1: the alcoholic strength and the alcoholic yield of the purple waxy wheat litchi prepared in the examples 1-5 are respectively higher than 20% vol and 20%; compared with the traditional litchi wine, the alcoholic strength of the litchi wine prepared by the method is improved by about one time, and the alcoholic strength and the alcoholic yield of the purple waxy wheat litchi wine prepared by the method are improved by about one time; meanwhile, the methanol content of the purple waxy wheat litchi wine prepared in the examples 1-5 is lower than 250mg/L, and the requirement of GB15037-2006 wine on the methanol content is met; in addition, the purple waxy wheat litchi wine prepared in examples 1-5 has the anthocyanin concentrated solution of the purple waxy wheat, so that compared with the traditional litchi wine, the anthocyanin content is greatly improved and is about 90mg/100mL, and the health care function of the traditional litchi wine is enhanced. Compared with the examples, the comparative examples 1,2 and 4 have reduced alcoholic strength and wine yield, and the anthocyanin content of the comparative example 3 has obviously reduced, so that the cold soaking and freezing concentration and extrusion puffing treatment in the invention have an effect on improving the alcoholic strength and the wine yield, and the mixed fermentation of the anthocyanin concentrated solution added with the purple waxy wheat has an effect on improving the anthocyanin content. Considering all examples and comparative examples together, it is known that the methanol content meets the national standard requirements, and it is proved that the treatment of low-temperature yeast fermentation and low-temperature standing in the invention is helpful for reducing the pectin content.

Test example 2

The sensory evaluation of the purple waxy wheat lychee wine prepared in experimental examples 1-5 and comparative examples 1-4 is carried out by referring to GB/T15308-2006 wine, a fruit wine general analysis method, GB/T33404-2016 white spirit sensory evaluation rules, GB/T33405-2016 white spirit sensory evaluation terms and QB/T4262-2011 lychee wine, and specifically comprises the following steps:

The color, texture, taste and aroma of the purple waxy wheat lychee wine are evaluated by adopting a nine-point scale method, the color, texture, taste and aroma of the purple waxy wheat lychee wine are fully divided into 36, 10 persons participating in sensory evaluation are totally involved in the sensory evaluation, and the purple waxy wheat lychee wine has the professional knowledge of brewing and tasting corresponding wines, and the sensory evaluation indexes are shown in table 2:

TABLE 2 sensory evaluation index

The sensory evaluation results are shown in table 3:

table 3 sensory evaluation results of the preparation of purple waxy wheat lychee wine of examples 1 to 5 and comparative examples 1 to 4

As can be seen from table 3: the color, texture, taste and aroma of the purple waxy wheat lychee wine prepared in examples 1-5 are all more than 7 minutes and the sensory total score is all more than 30 minutes, which are excellent in sensory characteristics, wherein the purple waxy wheat lychee wine prepared in example 1 is optimal; meanwhile, compared with the embodiments 1-5, the purple waxy wheat lychee wine prepared in the comparative examples 1-4 has the disadvantages in terms of color, texture, taste and aroma, and the purple waxy wheat lychee wine prepared by combining cold soaking with freeze concentration, anthocyanin extraction and extrusion puffing treatment has better wine body color and texture and richer taste and aroma.

In conclusion, the preparation method provided by the invention can effectively improve anthocyanin content, alcoholicity and wine yield in the composite fruit wine, enhance the color of the wine body, enrich the aroma and taste of the wine body and reduce the methanol content on the basis of keeping the quality of the composite fruit wine so as to enhance the safety of the composite fruit wine.

Although specific embodiments of the invention have been described in detail, it should not be construed as limiting the scope of protection of this patent. Various modifications and variations which may be made by those skilled in the art without the exercise of inventive faculty are within the scope of the claims presented herein.

Claims

1. The preparation method of the purple waxy wheat litchi wine is characterized by comprising the following steps of:

(1) Mixing litchi pulp with water, pulping to obtain litchi pulp, soaking, filtering, and freeze concentrating to obtain concentrated litchi juice; the mixing and pulping is carried out at the temperature of 5-10 ℃, and the mass ratio of litchi pulp to water is 1: 1-2; immersing the litchi pulp for 3-5 days at the temperature of 5-15 ℃; the freezing concentration is that the filtered filtrate is concentrated at the temperature of minus 20 to minus 10 ℃, the crystallization rate is controlled to be 50 to 60 percent, and the sugar content of the litchi juice is 220 to 300 g/L;

(5) Adding a clarifying agent into the filtrate obtained in the step (4) for clarifying, standing and filtering to obtain the purple waxy wheat lychee wine; the clarifying agent is pectase, chitosan and gelatin, and the mass ratio is 1: 1-3: 1.

2. The method for preparing the purple waxy wheat lychee wine according to claim 1, wherein the ultrasonic alcohol extraction process is as follows: under the condition of 40-60 ℃, the purple waxy wheat is prepared by the following steps of: 3-5, adding an ethanol solution containing citric acid, carrying out ultrasonic alcohol extraction for 1-2 hours, and centrifuging to collect supernatant; wherein the volume fraction of ethanol in the ethanol solution is 70-90%, and the mass fraction of citric acid is 0.5-1.5%.

3. The preparation method of the purple waxy wheat lychee wine according to claim 1, wherein in the step (2), adsorption is carried out by adopting resin to adsorb supernatant for 2-3 hours under the condition that the pH value is 3-5 and the temperature is 25-35 ℃, eluting with ethanol solution containing citric acid, and desorbing for 1-2 hours to obtain eluent, wherein the volume fraction of ethanol in the ethanol solution is 70-90%, and the mass fraction of citric acid is 0.5-1.5%; and concentrating the eluent at 40-55 ℃ under the pressure of 0.007-0.015 MPa for 30-60 min to obtain anthocyanin concentrated solution.

4. The preparation method of the purple waxy wheat lychee wine according to claim 1, which is characterized in that the extrusion and puffing in the step (3) are carried out on the purple waxy wheat flour with the water content of 12% -25% under the conditions that the temperature is 120-180 ℃, the spiral diameter is 50-60 mm, the main shaft rotating speed is 300-500 r/min, and the temperature is cooled to 60-65 ℃ after puffing; and (3) adding 0.1-0.2% of saccharifying enzyme by mass percent, and performing enzymolysis for 3-6 hours.

5. The preparation method of the purple waxy wheat lychee wine according to claim 1, wherein the mass ratio of the concentrated lychee juice to the anthocyanin concentrate to the purple waxy wheat enzymatic hydrolysate is 1:0.5 to 1.5: 2-5; the mass percentage of the added activated yeast is 1-2%; the fermentation process is that the fermentation is carried out for 1-3 days at 25-30 ℃, and then the fermentation is carried out at 15-18 ℃ until the total sugar content is 3.5-4.5 g/L.

6. The method for preparing the purple waxy wheat lychee wine according to claim 1, wherein in the step (4), the fermentation liquor is kept still at 4-8 ℃ until gel on the upper layer of the feed liquor stops increasing, and a filter with the pore diameter of 20-80 meshes is adopted for filtering.

7. The method for preparing the purple waxy wheat lychee wine according to claim 1, wherein the clarification is to add a clarifying agent into the filtrate at a concentration of 0.5-0.6 mg/mL for clarification, standing for 2-4 days, and filtering to obtain the purple waxy wheat lychee wine.

8. The purple waxy wheat lychee wine prepared by the preparation method of the purple waxy wheat lychee wine according to any one of claims 1-7.