Method for improving acid ester stability of medium-alcohol-content and low-alcohol-content baijiu

Abstract

The invention discloses a method for improving the acid ester stability of medium-alcohol and low-alcohol baijiu, which is characterized in that the alcohol content of high-alcohol baijiu is reduced only by adopting slurry-adding water, and the pH value of the slurry-adding water is required to be greater than or equal to 7.3 and the bicarbonate radical content is not less than 50mg / L. According to the method disclosed by the invention, a method system for thermodynamically influencing the hydrolysis rate of the ester substances in the medium-low-alcohol white spirit is constructed through the hydrolysis equilibrium of bicarbonate radicals, the ionization equilibrium of water and the hydrolysis equilibrium of the ester substances, so that the hydrolysis rate of the ester substances in the medium-low-alcohol white spirit after the alcohol content is reduced can be slowed down; therefore, the stability of ester components in the medium-alcohol and low-alcohol white spirit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of improving wine quality, and in particular to a method for improving the stability of low- and medium-alcohol liquor acid esters. Background Art

[0002] Medium- and low-alcohol liquors (20%-38% vol for low-alcohol liquor, 38%-45% vol for medium-alcohol liquor) are becoming increasingly popular among consumers, especially young ones, due to their low physical burden and low risk of intoxication. This is achieved by adding pulp to the high-alcohol base liquor to reduce the alcohol content. The pulp is water, which is added to dilute the ethanol concentration.

[0003] The addition of water (slurrying) during the alcohol reduction process disrupts the balance of the ethanol-water mixture, causing esters (such as ethyl acetate, ethyl caproate, and ethyl lactate) to hydrolyze, generating the corresponding acids (acetic acid, caproic acid, and lactic acid) and ethanol. This results in an increase in acid content and a decrease in ester content, which directly impacts the sensory quality of the wine. The reduction in esters (such as ethyl caproate and ethyl lactate), the main aroma components, weakens typical aroma characteristics such as floral and fruity aromas and cellar aromas, reducing aroma complexity. An increase in the acid-ester ratio (total acid / total ester) leads to a decrease in the wine's harmony, manifested as a prominent "watery" flavor and an enhanced sour and astringent sensation. When the acid-ester ratio exceeds 0.5, the wine loses the mellowness of traditional baijiu. This "acid increase and ester decrease" combination can lead to flavor degradation, rough taste, and a shortened shelf life in medium- and low-alcohol baijiu.

[0004] Currently, the problem of ester hydrolysis in medium and low-alcohol liquors is usually solved by adding stabilizers. Stabilizers are mainly large molecular proteins and polysaccharides. The hydrolysis of ester substances is delayed by the association between stabilizers and ester substances. However, large molecular substances have the risk of affecting the clarity of the liquor, are difficult to dissolve, and require a certain addition concentration to be controlled. The operation is cumbersome, the cost is high, and the stability effect is relatively poor. More importantly: according to the "Liquor Industry Terminology" (GB / T 15109-2021) and the "Beverage Alcohol Terminology and Classification" (GB / T 17204-2021) that will take effect in June 2022, the addition of any food additives (including stabilizers) to solid-state liquor is strictly prohibited. After the implementation of the new national standard, only "flavored liquor" (blended liquor) is allowed to use additives, but such products must be clearly labeled and do not fall into the category of traditional liquor. Therefore, no stabilizers can be added to medium and low-alcohol solid-state liquor to improve the stability of the liquor.

[0005] In addition, there is also the method of regulating the hydrolysis of esters by adjusting the content of beneficial trace elements in the slurry water, and increasing the probability of sol formation in the liquor system by increasing the organic acid salts of cations (such as zinc, calcium, potassium, sodium) and anions (such as acetate, lactate, caproate, butyrate ions), so as to achieve the purpose of inhibiting the decrease in the content of ester substances in the liquor and increasing the acid value. However, this method is also not suitable for solid liquor that meets the new national standard. In addition, this method is theoretically sound, but in practice it requires precise control of the ratio of various trace elements, and may accelerate the corrosion of stainless steel equipment, easily cause secondary contamination of metal ions, and destroy the balance of the liquor body. The operation is complicated and the effect is difficult to control, so the possibility of application is low.

[0006] The current approach is to blend solid base liquors with varying acid ester ratios to maintain the same acid ester ratio as possible after alcohol reduction, thereby ensuring the quality of the reduced liquor. This method can indeed improve the quality of low- to medium-alcohol liquors, but it does not change the fact that the ester components are hydrolyzed. Summary of the Invention

[0007] In response to the problems existing in the prior art, the present invention provides a method for improving the stability of acid esters in medium and low-alcohol liquors. This method can significantly improve the quality stability of medium and low-alcohol liquors on the shelves, especially improve the stability of total esters in medium and low-alcohol liquors, and delay the rate of hydrolysis of ester components to generate acid components.

[0008] A method for improving the stability of acid esters in medium and low-alcohol liquors, wherein only pulping water is used to reduce the alcohol content of high-alcohol liquor, wherein the pulping water is required to have a pH of ≥7.3 and a bicarbonate content of not less than 50 mg / L.

[0009] Preferably, the slurry water is selected from natural mineral water, natural soda water and groundwater.

[0010] Preferably, the alcohol content of the high-proof liquor is 55-65 degrees.

[0011] Preferably, the alcohol content of the medium-low alcohol liquor is 20-45 degrees.

[0012] Preferably, after the alcohol reduction treatment, the pH value of the wine does not exceed 5.5.

[0013] The hydrolysis of ester components into corresponding acids and alcohols is a reversible reaction. Adding water to reduce the alcohol content will lead to the hydrolysis of ester components, the ester substances will decrease, and the acid substances will increase until a new acid ester equilibrium is reached. This conforms to the thermodynamic laws of reversible reactions, but it may take several years to reach a new equilibrium of acid esters kinetically. Among them, factors that can affect the hydrolysis rate of ester substances will significantly affect the proportion of acid ester components in low-alcohol liquor on the shelf.

[0014] The hydrolysis of esters in medium- and low-alcohol liquors into acids and alcohols (because liquor is acidic, the hydrolysis of esters in liquor occurs under acidic conditions) requires H+ ions, which act as a catalyst in this process. When the H+ ion concentration is high, the esters in medium- and low-alcohol liquors hydrolyze quickly, manifesting as a rapid decrease. When the H+ ion concentration is low, the hydrolysis is relatively slow, manifesting as a relatively stable ester composition. In addition, bicarbonate ions can ionize into OH- ions in water, and there is an ionization equilibrium between OH- ions and H+ ions. Therefore, increasing the concentration of bicarbonate ions in the system can reduce the concentration of H+.

[0015] Therefore, by increasing the concentration of bicarbonate ions in the pulping water, the hydrolysis rate of ester substances in the medium and low-alcohol liquor after alcohol reduction can be slowed down, thereby improving the stability of the ester components in the medium and low-alcohol liquor.

[0016] Compared with using pure water to reduce the alcohol content, using natural water rich in bicarbonate (pH ≥ 7.3, bicarbonate content 50mg / L-450mg / L) to reduce the alcohol content, at room temperature for 12 months, reduced the total esters by 14% to 40%, and reduced the total acid by 30% to 55%; and after tasting, there was no adverse effect on sensory evaluation. This method can significantly delay the "increase in acid and decrease in esters" phenomenon of medium and low-alcohol liquors, thereby extending the quality period of medium and low-alcohol liquors on the shelf. It is only necessary to replace the appropriate pulping water for alcohol reduction, and the actual production process does not need to be changed. At the same time, the superimposed blending technology can significantly improve the quality of medium and low-alcohol liquors. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] Example

[0019] Highly fragrant base liquor (55-65 degrees) was used, and the alcohol content was adjusted using reduced-alcohol water with different bicarbonate contents. The samples were filtered and prepared into test samples. 6 types of reduced-alcohol water were used to mix liquors with 28 degrees, 33 degrees, 38 degrees, and 42 degrees, respectively. 0# of the liquors was pure water (made by reverse osmosis). The liquors were placed at room temperature for one year to observe the changes in total acid and total esters.

[0020] Table 1 Changes in total acids and esters of 28-proof Luzhou-flavor liquor prepared with different waters for reducing alcohol content at room temperature for one year

[0021]

[0022] Table 2 Changes of total acid and total esters in 33% Luzhou-flavor liquor prepared with different water for reducing alcohol content at room temperature for one year

[0023]

[0024] Table 3 Changes of total acid and total esters in 38% Luzhou-flavor liquor prepared with different water for reducing alcohol content at room temperature for one year

[0025]

[0026] Table 4 Changes of total acid and total esters in 42% Luzhou-flavor liquor prepared with different water for reducing alcohol content at room temperature for one year

[0027]

[0028] From the changes in total acid and total esters of 28-proof Luzhou-flavor liquor prepared with different waters for reducing alcohol content at room temperature for one year in Table 1, compared with the use of pure water (0#), the use of natural water rich in bicarbonate as the water for reducing alcohol content can significantly inhibit the increase in total acid and the decrease in total esters, and the higher the bicarbonate content, the better the effect. The same effect is also verified in Tables 2, 3, and 4. The difference is that in Table 1, the alcohol content of the original liquor is reduced the most, the amount of water used for reducing alcohol content is the largest, which is close to 57% of the total volume, and the stability of total acid and total ester is the worst. In Table 4, the alcohol content of the original liquor is reduced the least, the amount of water used for reducing alcohol content is the smallest, which is 35% of the total volume, and the stability of total acid and total ester is relatively good. In short, the use of natural water rich in bicarbonate can significantly improve the stability of total acid and total esters of high-proof liquor after alcohol reduction, thereby improving product quality.

[0029] The above embodiments are merely examples of preferred embodiments of the present invention and are not intended to be exhaustive. Persons skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A method for improving the stability of low- and medium-alcohol liquor acid esters, characterized in that: Only pulping water is used to reduce the alcohol content of high-proof liquor, and the pulping water is required to have a pH ≥ 7.3 and a bicarbonate content of not less than 50 mg / L.

2. The method according to claim 1, characterized in that The slurry water is selected from natural mineral water, natural soda water and groundwater.

3. The method according to claim 1, characterized in that The alcohol content of the high-proof liquor is 55-65 degrees.

4. The method according to claim 1, wherein The alcohol content of the medium-low alcohol liquor is 20-45 degrees.

5. The method according to claim 1, wherein After alcohol reduction, the pH value of the wine does not exceed 5.5.

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