CN112195082A

CN112195082A - Method for preparing fermented momordica grosvenori wine by applying lysozyme

Info

Publication number: CN112195082A
Application number: CN202011283921.5A
Authority: CN
Inventors: 夏咏梅; 李蜜月; 黄燕; 吴敬
Original assignee: Jiangnan University
Current assignee: Jiangnan University
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2021-01-08

Abstract

The invention discloses a method for preparing fermented momordica grosvenori wine by using lysozyme, belonging to the field of food engineering. The method takes the extraction residues for extracting the mogrosides as raw materials, and uses the lysozyme for food to decompose the cellulose in the extraction residues into glucose for fermentation, thereby replacing the use of cellulase; meanwhile, the lysozyme can also replace sulfur dioxide to be used as a bactericide to inhibit the growth of infectious microbes which influence the fermentation, then the wine yeast is used for inoculation and fermentation to prepare the fermented momordica grosvenori wine, and after the fermentation is finished, the residual lysozyme in the wine can also continue to inhibit the growth of the infectious microbes, thereby being beneficial to prolonging the shelf life.

Description

Method for preparing fermented momordica grosvenori wine by applying lysozyme

Technical Field

The invention relates to a method for preparing fermented momordica grosvenori wine by using lysozyme, belonging to the field of food engineering.

Background

Fructus Siraitiae Grosvenorii is fruit of perennial vine of Siraitia of Cucurbitaceae, and is named as Momordica grosvenorii, Larsonia simplicifolia, false fructus Momordicae Charantiae, and fructus Momordicae CharantiaeTortoise plastron, and the like. Fructus momordicae has the effects of eliminating phlegm, relieving cough, resisting inflammation, resisting oxidation, reducing blood sugar, reducing blood fat, protecting liver, resisting cancer, enhancing immunity and relaxing bowel, and is known as the 'immortal fruit'. The main effective component of the sugar is mogroside which is 300 times sweeter than cane sugar, and the calorie is only 1/50 of that of cane sugar compared with cane sugar with the same sweetness. In addition, fructus Siraitiae Grosvenorii is rich in fructose, glucose, flavonoid glycoside, mannitol, and V_E、V_CAnd 14 essential trace elements and macroelements, which are both medicinal and edible products recognized by the national ministry of health. Because the mogroside extract has complex extraction process and high price, and cannot be comprehensively popularized and used, in order to expand the application of mogroside, a literature report exists, and momordica grosvenori can be prepared into health-care beverages or health-care wine with various characteristics with medlar, liquorice, red dates, chrysanthemum and the like, for example, patent CN1216683A describes a mogroside and chrysanthemum health-care tea which is composed of momordica grosvenori, chrysanthemum, tea leaves, pseudo-ginseng roots and glossy ganoderma. Patent CN1373188A describes a preparation method of a momordica grosvenori and lycium barbarum health care wine: soaking fructus Siraitiae Grosvenorii, fructus Lycii, Poria, cortex Cinnamomi, herba Agastaches, radix Angelicae sinensis, semen Platycladi, fructus Chaenomelis, Hericium Erinaceus and Ganoderma in ethanol. Patent CN108949469A describes a red date health wine, which is composed of momordica grosvenori, red date, prepared rehmannia root, poria cocos, dogwood, astragalus, salvia miltiorrhiza, liquorice and mulberry. In addition, CN108641875 discloses a preparation method of momordica grosvenori wine, which is prepared by fermenting momordica grosvenori soaked in high-alcohol-content white spirit. However, the brewing reports of the momordica grosvenori wine are less at present, and the brewing process of the momordica grosvenori wine is complex, and the brewed fruit wine is poor in taste and the like.

In the process of fruit wine fermentation, bactericides are widely used, because some mixed bacteria such as acetic acid bacteria and lactobacillus which are harmful to fermentation are inevitably infected when fruit is squeezed into juice, and the mixed bacteria can cause that the fruit wine fermentation can not be normally carried out. In traditional fruit wine brewing, fruit pulp is generally sterilized by sulfur dioxide, for example, patent CN109181989A discloses a preparation method of navel orange fruit wine, and the amount of sulfur dioxide added in fruit juice during fermentation is 180-220 mg/kg. Patent CN106701417A discloses a method for preparing kiwi fruit wine, and the initial sulfur dioxide concentration of the fermentation liquid is 30 mg/kg. The sulfur dioxide serving as a bactericide can inhibit the growth, reproduction and metabolism of infectious microbes and promote the smooth fermentation of fruit wine, but the fruit wine has irritant 'sulfur smell' and 'burning' feelings and has certain toxicity. The country has clear regulations on the content of sulfite in fruit wine, so that finding a non-toxic bactericide which can be applied to the brewing process of the fruit wine is urgent.

Lysozyme is also called muramidase or N-acetylmuramyl polysaccharide hydrolase, is an alkaline enzyme which is specifically used for the cell wall of microorganisms and can decompose gram-positive bacteria, wall-dissolving micrococcus, sarcina flava, bacillus megaterium and the like. For example, CN105231408A discloses a method for preparing lysozyme soy sauce, which applies lysozyme to the preservation and freshness of soy sauce to prolong the shelf life of soy sauce. CN106577989A discloses a preparation method of a compound natural preservative for meat products. CN1338214A describes the application of lysozyme in milk products, and the milk products containing lysozyme have good immune function and can enhance the immunity and disease resistance of infants. The lysozyme is an important immune factor in human bodies, and is a natural, non-toxic, green and safe antiseptic bactericide. However, the temperature, pH value, chemical properties and complexation all affect the enzyme activity of lysozyme and have the problem of high cost.

Disclosure of Invention

[ problem ] to

The existing preparation process of the momordica grosvenori wine is to soak momordica grosvenori in alcohol and then mix, and the momordica grosvenori wine is lack of fermentation type. In other existing fruit wine fermentation processes, sulfur dioxide is used as a bactericide, and excessive application of sulfur dioxide causes the problems of poor taste and health of fruit wine.

[ solution ]

The invention provides a method for preparing fermented momordica grosvenori wine, which takes momordica grosvenori pulp as a raw material, and is fermented and brewed by using wine yeast (Saccharomyces cerevisiae), lysozyme is added in the fermentation process to be used as a bactericide, the alcohol content in the obtained beverage is 3.8-7.6% (20 ℃), the residual sugar content is 4-7g/L (calculated by reducing sugar), the total acid content is 3.0-5.5g/L (calculated by tartaric acid), and the pH value is 5.0-5.5.

The method for preparing the fermented momordica grosvenori wine comprises the following steps of:

1) obtaining a concentrated pulp

Pulping the momordica grosvenori pulp residues to obtain a pulp raw material, filtering, and controlling the solid content of filtrate to be 20% -25% to obtain momordica grosvenori concentrated pulp;

2) pretreating fermentation feedstock

Adjusting the concentrated siraitia grosvenorii pulp obtained in the step (1) with water to enable the sugar degree to be 75-140g/L, pH5.0 to be 5.0-6.0 and the solid content to be 10-15%, and then carrying out sterilization treatment; selecting sugar degree, pH value and solid content according to the alcohol degree of the fruit wine to be prepared;

3) fermentation: adding lysozyme into the sterilized siraitia grosvenorii pulp obtained in the step (2) to carry out enzymolysis treatment on the siraitia grosvenorii pulp to obtain fruit juice, then adding wine yeast, and fermenting at the temperature of 20-26 ℃ until the residual sugar (calculated by reducing sugar) is lower than 7 g/L;

4) refrigerating the wine liquid obtained in the step (3), and then filtering and sterilizing.

Optionally, the momordica grosvenori pulp residue in the step 1) is a raffinate of the momordica grosvenori from which the mogrosides is extracted.

Optionally, the sterilization of step 2) adopts high-temperature instant sterilization.

Optionally, the adding amount of the lysozyme in the step 3) is 705U/g.

Optionally, after adding lysozyme in the step 3), the temperature is kept at 25 ℃ for 72h so as to carry out enzymolysis reaction.

Optionally, the wine yeast in step 3) is red wine yeast or white wine yeast.

Optionally, the adding amount of the wine yeast in the step 3) is 0.3-1% of the mass of the fruit juice obtained by enzymolysis of lysozyme.

Optionally, the wine yeast of step 3) is activated before being added to the juice. Optionally, activating in water at 35 deg.C for 25-35 min.

Optionally, the refrigeration temperature in the step 4) is 4-10 ℃, and the refrigeration time is 3-5 days.

[ advantageous effects ]

The production process is simple, the momordica grosvenori pulp is pulped, filtered, added with enzyme and bacteria and fermented, the fermentation period is short, the fermentation period is 2-5 days, and the momordica grosvenori pulp is refrigerated for 3-5 days after fermentation.

The fermentation process of the invention uses lysozyme, thereby avoiding the influence of other mixed bacteria on the fermented fruit wine in the fermentation process, ensuring the smooth fermentation process and improving the taste of the momordica grosvenori wine. The lysozyme is used, so that sulfur dioxide can be prevented from being added, the flavor of the momordica grosvenori is kept, and the safety and health of the momordica grosvenori wine are ensured. Meanwhile, the lysozyme can also replace cellulase to decompose the cellulose in the fruit pulp into glucose which can be used for fermentation, so that the cellulose in the raw materials can be better utilized, the cost is reduced, and the fermentation efficiency is improved.

The fruit wine brewed by the invention is dark brown, has soft taste, moderate sweet and sour taste, no bitter taste and after-sweet taste, and has typical fructus momordicae flavor and fragrance.

Drawings

FIG. 1 Radar chart for sensory evaluation of lysozyme-containing fermented Momordica grosvenori wine

Detailed Description

The analysis method comprises the following steps:

alcohol content: high performance liquid chromatography. Analysis conditions were as follows: a Sugar-Par-1 calcium type cation column chromatography (6.5 mm. times.300 mm); the mobile phase is ultrapure water, and the flow rate is 0.5 mL/min; a RID detector; the amount of the sample was 10. mu.L.

Reducing sugar content: 3, 5-dinitrosalicylic acid method.

Solid content: constant weight method.

Total acidity: acid-base titration.

pH value: and (4) measuring by using a pH meter.

Total number of colonies: reference is made to the method for determining the total number of colonies in GB 4789.2.

The enzyme activity definition and enzyme activity determination method of the lysozyme comprises the following steps: the decrease in absorbance at 450nm per minute of 0.001 at a defined condition (25 ℃, pH 6.2) is defined as 1 enzyme activity unit (1U). The specific activity of the enzyme is U/g.

The method for measuring the lysozyme activity comprises the following steps: spectrophotometric determination, dissolving a certain amount of muramidase microballon powder (from Shanghai-derived leaf Biotech Co., Ltd.) in a certain amount of phosphate buffer (pH 6.2) at 450nm, making the absorbance value about 1.3 to obtain a substrate solution, holding 2.5mL of the substrate solution in a 1cm cuvette, keeping the temperature in a water bath at 25 ℃, adding 0.5mL of enzyme solution (weighing 5mg of lysozyme to be dissolved in 1mL of phosphate buffer with the concentration of 0.1mol/L and the pH value of 6.23, fixing the volume to 10mL, then diluting 150 times for later use), starting timing, recording the reading Al during the reaction lmin and the reading A2 during the reaction for 2min, and calculating the enzyme activity by using a formula.

Sensory evaluation of the fermented momordica grosvenori wine: samples were prepared and evaluated using the sensory test method of section 3.2 in GB/T15038-2006. The evaluation methods and score arrangement are shown in Table 1, total score 50. The samples were scored for 6 men and 6 women, respectively. Each sample was rated 3 times and scored, with each term taking the arithmetic mean of its 3 scores. The scores of all the indexes are the arithmetic mean of all the scores of all the indexes on the corresponding indexes.

TABLE 1 sensory evaluation Table

Example 1: fruit-flavor fruit wine prepared by optimal fermentation of red wine yeast

(1) Obtaining concentrated pulp

Adding water 2.5 times the weight of fructus Siraitiae Grosvenorii pulp (the residue after extraction of mogroside) at room temperature, pulping to obtain fructus Siraitiae Grosvenorii pulp, and filtering with 20 mesh sieve to obtain fructus Siraitiae Grosvenorii concentrated pulp (containing pulp and solid content of 20%).

(2) Pretreatment of fermented raw materials

Adjusting the sugar degree index of the concentrated siraitia grosvenorii pulp obtained in the step (1) to 85-95g/L (different batches of fruits have different sugar degrees), pH value of 5.65 and solid content of 11% by using drinking water, sterilizing at 110 ℃ for 15s at instant high temperature, and cooling to room temperature for later use.

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

And (3) when the temperature of the fermentation raw material sterilized in the step (2) is reduced to 25 ℃, adding 705U/g lysozyme (purchased from Shanghai Yuanmu Biotech Co., Ltd.), stirring, inoculating into a fermentation tank, and performing enzymolysis for 72 hours in the fermentation tank to obtain the fruit juice.

② activation of Yeast

Red wine yeast (yeast special for wine and fruit wine, RW type, purchased from Angel Yeast Co., Ltd., Hubei, China) was dispersed in warm water of 35 deg.C (5g yeast powder, dispersed in 95g sterile warm water) to obtain 5% yeast, and activated for 30 minutes.

Inoculating yeast and fermenting

Inoculating the activated red wine yeast in the step II into the lysozyme-containing fruit juice (containing fruit pulp) obtained by enzymolysis in the step I according to the proportion of 0.7 percent of final concentration (0.7g of yeast powder/99.3 g of fruit juice), controlling the fermentation temperature to 25 ℃ through an external circulation water bath, fermenting until the alcoholic strength is not increased and the residual sugar content (calculated by reducing sugar) is close to 5.0g/L, and finishing fermentation. The fermentation time amounted to 4 days.

(4) Refrigerating, filtering and sterilizing

And (4) refrigerating the wine liquid obtained by fermentation in the step (3) at 4 ℃ for 7 days, and filtering while the wine liquid is cold, wherein the obtained wine body is clear and transparent. And filtering the wine body after primary filtration by adopting diatomite and a 0.20 mu m biological membrane, and filling to obtain the fermented fruit wine product.

The obtained fermented fruit wine product has alcohol content of 4.71% (V/V), residual sugar content (calculated by reducing sugar) of 4.85g/L, acidity of 4.3g/L, pH value: 5.15; solid content: 4.40 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has harmonious and soft wine body, moderate sweet and sour taste, no bitter taste and after-sweet taste, and has typical and intense fructus momordicae flavor and fragrance. The sensory evaluation results of the beverage flavor are shown in table 4.

Example 2: preparation of strong type momordica grosvenori wine by red wine yeast

(1) Obtaining concentrated pulp

Same as example 1 step (1)

(2) Pretreatment of fermentation feedstock

Adjusting the sugar degree index of the concentrated siraitia grosvenorii pulp obtained in the step (1) to 95-105g/L (different fruits in different batches), adjusting the pH value to 5.50 and the solid content to 12% by using drinking water, sterilizing at 110 ℃ for 15s at instant high temperature, and cooling to room temperature for later use.

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

② activation of Yeast

Red wine yeast (yeast special for wine and fruit wine, RW type, purchased from Angel Yeast Co., Ltd., Hubei, China) was dispersed in 35 deg.C warm water (5g of yeast powder was dispersed in 95g of sterile warm water), and activated for 30 minutes.

Inoculating yeast and fermenting

Inoculating the activated red wine yeast in the step II into the lysozyme-containing fruit juice (containing fruit pulp) obtained by enzymolysis in the step I according to the proportion of 0.5 percent of final concentration (0.5g of yeast powder/99.5 g of fruit juice), controlling the fermentation temperature to 25 ℃ through an external circulation water bath, fermenting until the alcoholic strength is not increased and the residual sugar content (calculated by reducing sugar) is close to 5.0g/L, and finishing fermentation. The fermentation time amounted to 5 days.

(4) Refrigerating, filtering and sterilizing

And (3) refrigerating the wine liquid obtained by fermentation in the step (3) at 4 ℃ for 5 days, and filtering while the wine liquid is cold (centrifuging or plate-and-frame filtering to obtain clear and transparent fruit wine), wherein the wine body is clear and transparent. And filtering the wine body after primary filtration by adopting diatomite and a 0.20 mu m biological membrane, and filling to obtain the fermented fruit wine product.

The obtained fermented fruit wine product has alcohol content of 5.01% (V/V), residual sugar content (calculated by reducing sugar) of 4.68g/L, acidity of 4.2g/L, pH value: 5.26; solid content: 4.36 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has harmonious and soft wine body, moderate sweet and sour taste, no bitter taste and after-sweet taste, and has typical and intense fructus momordicae flavor and fragrance. The sensory evaluation results of the beverage flavor are shown in table 4.

Comparative example 1 fermentation Process No Sterilization

This comparative example differs from example 2 in that: and (3) after the temperature of the fermentation raw materials is reduced to 25 ℃, adding a bactericidal substance lysozyme, and inoculating activated red wine yeast for fermentation. The other process parameters were kept the same as in example 2.

The alcohol content of the obtained product is 4.93 percent (V/V), the residual sugar content (calculated by reducing sugar) is 4.85g/L, the acidity is 6.1g/L, and the pH value: 5.07; solid content: 4.47 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has the taste and fragrance of the momordica grosvenori, is sour in taste, free of bitter and astringent taste, has aftersweet taste, and sensory evaluation results of the flavor of the beverage are shown in table 4.

Comparative example 2 fermentation Using Sulfur dioxide for Sterilization

This comparative example differs from example 2 in that: and (3) after the temperature of the fermentation raw materials is reduced to 25 ℃, 100mg/L of sulfur dioxide is added to replace lysozyme, and activated red wine yeast is inoculated for fermentation. Other process parameters were kept consistent.

The alcohol content of the obtained product is 5.02% (V/V), the residual sugar content (calculated by reducing sugar) is 4.80g/L, the acidity is 4.7g/L, and the pH value: 5.18 of; solid content: 4.46 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has the taste and fragrance of the momordica grosvenori, is moderate in sour and sweet, bitter in taste and aftersweet, and sensory evaluation results of the beverage flavor are shown in table 4.

Example 3: method for preparing fen-flavor momordica grosvenori wine by fermenting white wine yeast

(1) Concentrating the pulp to obtain

Same as example 1, step (1).

(2) Pretreatment of fermentation feedstock

Same as example 2, step (2).

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

The same procedure as in step (3) of example 2 was repeated.

② activation of Yeast

White wine yeast (yeast special for wine and fruit wine, SY type, purchased from Angel Yeast GmbH, China Hubei) is dispersed in 35 deg.C warm water at a ratio of 5% (5g yeast powder is dispersed in 95g sterile warm water), and activated for 30 min.

Inoculating yeast and fermenting

Inoculating the white wine yeast (SY type) in the step (II) into the lysozyme-containing fruit juice (containing fruit pulp) obtained by enzymolysis in the step (I) according to the proportion of 0.5 percent of final concentration (0.5g of yeast powder/99.5 g of fruit juice), controlling the fermentation temperature to be 25 ℃ through an external circulation water bath, fermenting until the alcoholic strength is not obviously increased, and the residual sugar content (calculated by reducing sugar) is close to 5.0g/L, and finishing the fermentation. The fermentation time amounted to 5 days.

(4) Refrigerating, filtering and sterilizing

Same as example 1, step (4).

The alcohol content of the obtained product is 4.93 percent (V/V), the residual sugar content (calculated by reducing sugar) is 4.75g/L, the acidity is 4.6g/L, and the pH value: 5.24; solid content: 4.42 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has faint scent, is pleasant, has sour taste, no bitter taste, good aftertaste, the taste and the fragrance of the momordica grosvenori, and the sensory evaluation result of the beverage flavor is shown in table 4.

Comparative example 3 No Sterilization during fermentation

The difference between the comparative example and the example 3 is that after the temperature of the fermentation raw materials in the step (3) is reduced to 25 ℃, the sterilization substance lysozyme is not added, and the activated white wine yeast is inoculated for fermentation. The other process parameters were kept consistent with example 3.

The alcohol content of the obtained product is 4.79% (V/V), the residual sugar content (calculated by reducing sugar) is 4.45g/L, the acidity is 6.8g/L, and the pH value: 5.03; solid content: 4.56 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has the taste and fragrance of the momordica grosvenori, is sour in taste, free of bitter and astringent taste, has aftersweet taste, and sensory evaluation results of the flavor of the beverage are shown in table 4.

Comparative example 4 Sterilization with Sulfur dioxide in fermentation Process

The difference between the comparative example and the example 3 is that 100mg/L of sulfur dioxide is added to replace lysozyme after the temperature of the fermentation raw material in the step (3) is reduced to 25 ℃, and activated white wine yeast is inoculated for fermentation. The other process parameters were kept consistent with example 3.

The alcohol content of the obtained product is 4.84% (V/V), the residual sugar content (calculated by reducing sugar) is 4.95g/L, the acidity is 4.1g/L, and the pH value: 5.31; solid content: 4.37 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has the taste and fragrance of the momordica grosvenori, is moderate in sour and sweet, bitter in taste and aftersweet, and sensory evaluation results of the beverage flavor are shown in table 4.

Example 4: preparation of strong wine flavor type momordica grosvenori wine

(1) Concentrating the pulp to obtain

Adding water 2.2 times of the weight of the pulp residue of the momordica grosvenori at room temperature, pulping to obtain a momordica grosvenori pulp raw material, filtering through a 20-mesh sieve, and concentrating to obtain the momordica grosvenori concentrated pulp (with the solid content of 22%).

(2) Pretreatment of fermentation feedstock

Adjusting the sugar degree index of the fermentation liquor of the concentrated siraitia grosvenorii fruit pulp obtained in the step (1) to 130-140g/L (different fruits in different batches), pH5.48 and solid content of 15% by using drinking water, sterilizing at 110 ℃ for 15s at instant high temperature, and cooling to room temperature for later use.

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

The same procedure as in step (3) of example 2 was repeated.

Activation of yeast

Red wine yeast (yeast special for wine and fruit wine, RW type, purchased from Angel Yeast Co., Ltd., Hubei, China) was dispersed in warm water of 35 ℃ at a ratio of 5% (5g yeast powder, 95g sterile warm water) and activated for 25 minutes.

Sixthly, inoculating yeast and fermenting

Inoculating red wine yeast (RW) in the step II into the lysozyme-containing juice (containing fruit pulp) obtained by enzymolysis in the step I according to the proportion of 1 percent of final concentration (1g of yeast powder/99 g of fruit juice), controlling the fermentation temperature to 25 ℃ through an external circulation water bath until the alcoholic strength is not obviously increased, and finishing the fermentation when the residual sugar content (calculated by reducing sugar) is close to 7.0 g/L. The fermentation time amounted to 5 days.

(4) Refrigerating, filtering and sterilizing

And (4) cooling the wine liquid obtained in the step (3) to 8 ℃, refrigerating for 3 days at 8 ℃, filtering while the wine liquid is cold, and clarifying and transparent the wine body. And filtering the wine body after primary filtration by adopting diatomite and a 0.20 mu m biological membrane, and filling to obtain the fermented fruit wine product.

The alcohol content of the obtained product is 6.54% (V/V), the residual sugar content (calculated by reducing sugar) is 6.84g/L, the acidity is 5.3g/L, and the pH value: 5.16; solid content: 5.69 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has strong wine flavor, sweet taste, no bitter taste, good aftertaste, the taste and the fragrance of the momordica grosvenori, and sensory evaluation results of the beverage flavor are shown in table 4.

Example 5: preparation of faint scent type fructus Siraitiae Grosvenorii wine

(1) Concentrating the pulp to obtain

Adding 2.2 times of water by weight at room temperature for pulping to obtain raw material of fructus Siraitiae Grosvenorii pulp, filtering with 20 mesh sieve, and concentrating to obtain fructus Siraitiae Grosvenorii concentrated pulp (solid content 22%).

(2) Pretreatment of fermentation feedstock

Adjusting the sugar degree index of the fermentation liquor of the concentrated siraitia grosvenorii fruit pulp obtained in the step (1) to 75-85g/L (different fruits in different batches), pH5.57 and solid content of 10% by using drinking water, sterilizing at 110 ℃ for 15s at instant high temperature, and cooling to room temperature for later use.

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

The same procedure as in step (3) of example 2 was repeated.

② activation of Yeast

White wine yeast (yeast special for wine and fruit wine, SY type, purchased from Angel Yeast GmbH, Hubei, China) is dispersed in 35 deg.C warm water at a ratio of 5% (5g yeast powder, 95g sterile warm water) and activated for 35 minutes.

Inoculating yeast and fermenting

And (2) inoculating the white wine yeast obtained in the step (II) into the lysozyme-containing juice (containing fruit pulp) obtained in the step (I) through enzymolysis treatment according to the proportion of 1% of final concentration (1g of yeast powder/99 g of fruit juice), controlling the fermentation temperature to be 25 ℃ through an external circulating water bath, fermenting until the alcoholic strength is not obviously increased, and ending the fermentation until the residual sugar content (calculated by reducing sugar) is close to 5.0 g/L. The total fermentation time was 3 days.

(4) Refrigerating, filtering and sterilizing

And (4) cooling the wine liquid obtained in the step (3) to 10 ℃, refrigerating for 3 days, filtering while the wine liquid is cold, and clarifying and transparent the wine body. Filtering the wine body after primary filtration by adopting diatomite and a 0.2 mu m biological membrane, and filling.

The alcohol content of the obtained product is 3.86% (V/V), the residual sugar content (calculated by reducing sugar) is 4.71g/L, the acidity is 3.2g/L, and the pH value: 5.17; solid content: 3.64 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine is dark brown, has faint scent, pleasant taste, soft mouthfeel, no bitter taste, light aftersweet taste, the taste and the fragrance of the momordica grosvenori, and sensory evaluation results of the flavor of the beverage are shown in a table 4.

Example 6: preparation of fruity type momordica grosvenori wine

(1) Concentrating the pulp to obtain

Adding 1.8 times of water by weight at room temperature, pulping to obtain raw materials, filtering with a 20-mesh sieve, and concentrating to obtain fructus Siraitiae Grosvenorii concentrated pulp (solid content 25%).

(2) Pretreatment of fermentation feedstock

Same as example 2, step (2).

(3) Fermentation of

Fermentation raw material and lysozyme receiving tank

The same procedure as in step (3) of example 2 was repeated.

② activation of Yeast

White wine yeast (SY type, purchased from Angel Yeast Ltd, Hubei, China) was dispersed in 35 deg.C warm water at a ratio of 5% (5g yeast powder, dispersed in 95g sterile warm water, yeast mass concentration 5%), and activated for 25 minutes.

Inoculating yeast and fermenting

Inoculating the white wine yeast (SY type) in the step II into the lysozyme-containing fruit juice (containing fruit pulp) obtained by enzymolysis in the step I according to the proportion of 0.3 percent of final concentration (0.3g of yeast powder/99.7 g of fruit juice), controlling the fermentation temperature by using an external circulation water bath at 25 ℃, and ending the fermentation until the alcoholic strength is not obviously increased and the residual sugar content (calculated by reducing sugar) is close to 5.0 g/L. The fermentation time was 5 days.

(4) Refrigerating, filtering and sterilizing

And (4) cooling the wine liquid obtained in the step (3) to 4 ℃, refrigerating for 4 days at 4 ℃, filtering while the wine liquid is cold, and clarifying and transparent the wine body. Filtering the primarily filtered wine body by adopting diatomite and a 0.2 mu m biological membrane, and filling to obtain the fermented fruit wine product.

The alcohol content of the obtained product is 5.09% (V/V), the residual sugar content (calculated by reducing sugar) is 4.43g/L, the acidity is 4.1g/L, and the pH value: 5.34; solid content: 4.27 percent. The detailed physical and chemical indexes are shown in Table 2. The brewed fruit wine has dark brown color, strong fruit flavor, light wine flavor, proper sour and sweet taste, no bitter and astringent taste and aftersweet taste. The sensory evaluation results of the beverage flavor are shown in table 4.

TABLE 2 physicochemical indices of Momordica grosvenori wines obtained in examples 1 to 6 and comparative examples 1 to 4

According to the physicochemical indexes, the alcoholic strength range of the fruit wine obtained in the embodiment of the invention is 3.8-7.6%, the acidity range is 3.0-5.5g/L, the brewed fruit wine is dark brown, has the flavor and fragrance of the momordica grosvenori, is proper in sour and sweet, and is suitable for daily drinking. The embodiment 4 has the greatest difference from the embodiments, mainly caused by the initial solid content of the fermentation liquid, different solid contents and different sugar contents, and has great influence on physical and chemical indexes. The difference between the other examples is due to the difference in yeast type, amount added, etc. While the fruit wine obtained by fermenting in the comparative examples 1 and 3 has sour and astringent taste and acidity of 6-7g/L, in the comparative examples 2 and 4, although the physicochemical indexes are in the reasonable range pursued by the examples, the bactericide SO₂Adding into the fruit wine to fermentThe irritating 'sulfur taste' and 'burning' sensation cause the fruit wine to have poor taste.

TABLE 3 measurement results of the total number of colonies in examples 1 to 6 and comparative examples 1 to 4 during fermentation

Note that "/" indicates no detection, since both examples 1 and 5 had an end-of-fermentation time of less than 5 dd. The colony detection method refers to the determination method of the total number of colonies in GB 4789.2-2016.

The results of the measurement of the total number of the bacterial colonies in the fermentation process show that the bacterial colonies can reach SO degree by adopting lysozyme sterilization in the fermentation process₂The sterilization effect is similar to that of sterilization, so that the fermentation process is smoothly carried out.

TABLE 4 sensory evaluation results of Momordica grosvenori wines obtained in examples 1 to 6 and comparative examples 1 to 4

The evaluation result can obtain the momordica grosvenori wine brewed by the method, which has the advantages of pleasant and harmonious color, transparency, clearness, soft mouthfeel, proper sweetness and sourness, no bitter taste and peculiar smell, and typical and unique momordica grosvenori flavor and fragrance. The physical and chemical indexes of the fruit wine without any bactericide in comparative examples 1 and 3 are mostly close to those of the corresponding examples, but the fruit wine has high acidity, low pH value, poor taste and strong sour taste from the aspect of sensory evaluation indexes, and the fermentation process is infected with infectious microbes and the yeast fermentation is influenced because the bactericide is not added. Comparative examples 2 and 4 adopt sulfur dioxide as a bactericide, and it is known from the data of physicochemical indexes (table 2) and sensory evaluation (table 4) that although the possibility of contamination is reduced by the addition of sulfur dioxide, the yeast activity is also affected to some extent by sulfur dioxide, and the bitter taste of the momordica grosvenori wine is increased. In the embodiment, the lysozyme can be used as a bactericide and can also decompose cellulose to convert the cellulose into glucose required by fermentation, so that the reducing sugar content in the raw materials is improved (the reducing sugar content of fruit juice per milliliter is increased by 8-10mg), and the fermentation result shows that the alcoholic strength of the fermented fruit wine is relatively improved relative to that of a comparative example.

In general, the addition of lysozyme provides excellent growth environment and application substances for yeast, so that the fruit wine fermented by the method is fragrant and pleasant, has proper mouthfeel and no harmful substances, and increases the preference degree of drinkers on the fruit wine from the aspects of mouthfeel and psychology.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for preparing momordica grosvenori wine is characterized in that the momordica grosvenori wine is obtained by yeast fermentation and comprises the following steps:

1) obtaining a concentrated pulp

2) pretreating fermentation feedstock

Adjusting the concentrated siraitia grosvenorii pulp obtained in the step (1) by using water to enable the sugar degree of the concentrated siraitia grosvenorii pulp to be 75-140g/L, the pH value to be 5.0-6.0 and the solid content to be 10-15%, and then carrying out sterilization treatment;

3) fermentation: adding lysozyme into the sterilized concentrated siraitia grosvenorii pulp obtained in the step (2) to carry out enzymolysis treatment on the siraitia grosvenorii pulp to obtain fruit juice, then adding wine yeast, and fermenting at the temperature of 20-26 ℃ until the residual sugar is lower than 7 g/L;

2. The method for preparing momordica grosvenori wine according to claim 1, wherein the momordica grosvenori pulp residue of step 1) is a raffinate of momordica grosvenori from which mogrosides is extracted.

3. The method for preparing momordica grosvenori wine according to claim 1, wherein the lysozyme in step 3) is added in an amount of: 705U lysozyme per g of concentrated siraitia grosvenorii pulp.

4. A method for preparing momordica grosvenori wine according to claim 1 or 3, wherein the lysozyme is added in step 3), and then the mixture is incubated at 25 ℃ for 72 hours to allow the enzymolysis reaction.

5. A method of preparing momordica grosvenori wine according to claim 4, wherein the wine yeast is red wine yeast or white wine yeast.

6. The method for preparing momordica grosvenori wine according to claim 1 or 5, wherein the wine yeast is added in an amount of 0.3% -1% of the mass of the fruit juice obtained by lysozyme enzymolysis.

7. A method of preparing momordica grosvenori wine according to claim 6, wherein the wine yeast is activated prior to addition to the juice.

8. The method for preparing momordica grosvenori wine according to claim 1, wherein the fermentation in step 3) is performed for 3-5 days.

9. The method for preparing momordica grosvenori wine according to claim 1, wherein the alcohol content is 3.8% -7.6%, the residual sugar content is 4-7g/L, the total acid content is 3.0-5.5g/L, and the pH is 5.0-5.5.

10. Fermented momordica grosvenori wine prepared according to the method of any one of claims 1 to 9.