Harmful ingredients in wine and their hygiene problems
作者：admin 点击次数：139 发布时间：2025-06-13
The production of liquor has gone through a series of complex biochemical and physicochemical processes, and a variety of factors such as raw materials, strains, production technology and equipment, and environment affect the quality of liquor, which often bring people or produce some toxic and harmful substances, which can cause acute or chronic poisoning of drinkers, and the health quality of liquor directly affects the health of drinkers.
(1) Hygienic requirements for distilled spirits
Swallow distilled liquor is a high-grade liquor obtained by distillation of fermented raw liquor or fermented mash. 1. Control methanol content
Methanol comes from the pectin in the raw material. Pectin is mainly found in the interstitium and cell wall of the peel, seeds, roots, tubers and other cells of plants, and is decomposed into pectinate methanol under the action of pectinase or acid and alkali. The content of raw materials is high, and the methanol content in wine is high, such as potatoes, fruits, hard fruits, bran and other raw materials made of wine with high methanol content. When Aspergillus niger is used as a saccharification starter or when liquid fruit juice wine is clarified with pectinase, the methanol content in the wine is often higher, and the methanol content will also be increased if the saccharification fermentation time is too long.
Methanol decomposes slowly in the body and has an accumulation effect, which has a direct toxic effect on the body's tissue cells, and has the strongest toxic effect on the optic nerve. Methanol is not as rapid as ethanol oxidized to carbon dioxide and water, methanol oxidized to formaldehyde and formic acid are more toxic substances, formaldehyde and formic acid are 30 times more toxic than methanol, respectively, which explains why very small amounts of methanol can sometimes cause chronic poisoning. The optic nerve is most sensitive to the toxic effects of methanol and can lead to retinal damage and even blindness. On the other hand, it may be due to the imbalance of acid-base balance in the body caused by methanol and the lactic acid produced by formic acid and metabolic disorders in the body, which often makes the body appear acidosis. Headache, nausea, vomiting, stomach pain and blurred vision can occur after 6~24 hours of methanol entering the body, followed by dyspnea, paralysis of the respiratory center, cyanosis, and sometimes coma for several days, and even death. Visual impairment and even blindness often occur when the general state is restored. A one-time intake of more than 4g of methanol can cause acute poisoning, with clinical manifestations of headache, nausea, vomiting, stomach pain and blurred vision, and in severe cases, dyspnea, hypokalemia, coma and death. The self-dose is 7~8mL, and the lethal dose is 30~100mL. Long-term ingestion of small amounts can lead to chronic poisoning, in addition to headache, dizziness, digestive disorder, characteristic clinical manifestations of visual field narrowing and uncorrectable vision loss. China stipulates that the methanol content of liquor using grains as raw materials shall not exceed 0.04g/100mL, and that of substitutes such as dried potatoes shall not exceed 0.12g/100mL (both with an alcohol content of 60%). The amount of methanol in alcohol is not only related to the type of raw materials used to produce alcohol, but also related to the production process, such as the selection of raw materials, the cooking and distillation process of raw materials, etc. 2. Control the content of fusel oil
Fusel oil is a class of mixtures with high boiling points, mainly alcohols, including n-propanol, isobutanol and isoamyl alcohol, among which isoamyl alcohol content is higher. The liquid is light yellow or brown in color and has a peculiar odor.
Fusel oil is the result of protein decomposition in the raw materials or proteolysis of yeast bacteria in the fermentation process of liquor making, which further separates ammonia, decarboxylation and alcohol, and the alcohol generated at this time is fusel oil, which is stored in the fermented mash or fermented mature mash.
During fermentation, most of the higher alcohols are produced from amino acids in the presence of glucose. For example, pyruvate produced by the fermentation of glucose can react with cystine to form alanine and a-keto-isocaproic acid, and then detached to form isovaleraldehyde, which can be returned to isoamyl alcohol, the main component of fusel oil. In addition, when sucrose is present, it can also promote the production of higher alcohols.
The yield of fusel oil is generally 0.3%~0.7% of the ethanol yield, and in the fermentation process, the amount of fusel oil is related to the raw materials used, and the composition of yeast and nutrients. When the protein content in the raw materials is high, the fusel oil content in the wine is also high, for example, when corn is used as raw material, the fusel oil content in the distiller's grains prepared from sweet potato is higher. The distillation of solid liquor adopts the intermittent distillation of soil retorts, and the fusel oil content is the largest in the head, which is concentrated in the area of alcohol concentration of 75%~80% (volume fraction). In order to concentrate fusel oil in the extraction area as much as possible, it is necessary to make the heating steam volume, the pressure of the reactor, the feed amount and the cooling water volume of the crude distillation tower and the rectification tower are in a relatively stable state, and the above operations must be carried out more accurately, so that it is possible to obtain alcohol that meets the national standard of food hygiene.
The toxicity and anesthetic power of higher alcohols are related to the length of the carbon chain, and the longer the carbon chain, the stronger the toxicity, such as the toxicity of pentanol is 39 times greater than that of ethanol. Fusel oil decomposes and oxidizes slowly in the body, has a long time of action, and is more sexual and anesthetic than ethanol, which can congest the central nervous system and cause severe headaches and drunkenness. Trace fusel oil is a component of the aromatic smell of wine. The results of gas chromatography for the determination of various wines generally contain n-propanol, isobutanol and isoamyl alcohol, among which the content of isoamyl alcohol is higher. Famous liquors such as Moutai and Luzhou Tequ also contain a small number of positive alcohols. It has been proved by animal experiments that higher alcohols have certain toxicity, so there should be certain requirements for the content of fusel oil in wine. The distillation of solid liquor adopts intermittent distillation of soil retorts, and the fusel oil content is the largest in the head, so it is necessary to pinch the head and remove the tail.
For liquor obtained from sugary or starchy raw materials, saccharification, fermentation and distillation, the fusel oil content ≤ 0.15g/m; Those who use rice as raw material ≤ 0.2g/100mL (above 60% distilled liquor as the standard, higher or lower than 60% is converted into 60%).