Traditional homemade fermented foods include kimchi, rice wine, fermented bean curd, etc. Homemade yogurt, enzyme foods, etc. have now become a popular fashion. Many people believe that making fermented foods by themselves not only has better raw materials, more hygienic operation, safer added bacteria, fewer food additives, and more complete nutrient retention of the finished product, but also the fun of DIY in the process. As everyone knows, there are many safety hazards in homemade fermented food.
Self-made fermented food lacks technical guarantee
Fermented food is the result of humans using beneficial microorganisms to transform food. After ordinary food materials are fermented, they can become another food with a unique flavor. Traditional fermentation technology has benefited from the development of modern food industry technology, and has formed a large-scale food fermentation industry, producing various fermented products such as wine, soy sauce, vinegar, monosodium glutamate, fermented dairy products and so on. Industrialized fermented food production must implement strict processing technology specifications and product standards to ensure its safety; self-made fermented foods often lack corresponding technical guarantees, improper operation, substandard sanitary conditions, lack of sterilization and disinfection conditions, etc., all easily lead to Food safety issues. In recent years, food safety cases caused by homemade fermented foods are not uncommon: In October 2020, a resident of Heilongjiang Province and his relatives ate fermented rice noodles “sour soup” stored in the refrigerator for one year, resulting in rice yeast acidosis. 9 All the poisoned persons died; in April 2018, a resident of Xiamen City suffered acute toxic optic neuropathy after drinking homemade wine, and his eyes were nearly blind… From the cases that occurred over the years, it can be seen that the food safety problems of homemade fermented food, Mainly from the hazards of microorganisms and toxic chemicals.
Common safety hazards of homemade fermented food
1. Homemade fermented cereal products
┆ ┆ security risks BKA poisoning
all over the country have made the habit of fermented cereal products, fermented cornmeal to the north, fermented glutinous millet, smelly sub-ballast, sub-sour soup, beans, and other princess mainly south Fermented rice noodles are mostly used to make glutinous corn glutinous rice noodles, glutinous rice cakes, glutinous rice cakes, vinegar jelly, etc. Many poisoning incidents in recent years are related to these foods.
The production process of fermented cereals has a common feature, that is, it requires a long period of fermentation or soaking. In the process of crushing, soaking, processing, storage, etc., especially in summer and autumn, fermented cereal products are easily contaminated by Pseudomonas cocos. The bacterium can produce extremely toxic saccharic acid, even if it is boiled at high temperature, its toxicity cannot be destroyed. There is no cure for human being poisoned, and the fatality rate is over 50%.
2. brewed liquor
┆ ┆ safety hazards of methanol poisoning, an explosion
in a large sale of the grape season, many consumers will be brewed wine. In fact, the grapes used for winemaking are specialized varieties, and not all grapes on the market are suitable for winemaking. Moreover, wine making needs to go through processes such as raw material cleaning, crushing, fermentation, pressing, clarification and separation, and aging. In the process of industrial wine making, every process has strict quality control and inspection. The cleanliness and sanitation of grape raw materials and proper condition control during fermentation (such as temperature, dissolved oxygen, pH value, rotation speed during stirring, etc.) are key factors. Otherwise, bacteria contamination will occur and the finished product will deteriorate. It is worth noting that a large amount of carbon dioxide is produced during the wine brewing process. If the fermentation vessel is closed or the materials are not properly selected, it may explode due to gas expansion.
In addition to wine, other self-brewed fruit wines, rice wines, etc. should also be noted: during the fermentation process, the main metabolite of yeast is ethanol, but at the same time a little methanol is also produced. During self-brewing, due to the lack of processes and technology to remove methanol, the methanol content in the finished product is likely to exceed the standard. Methanol can inhibit the central nervous system, causing metabolic acidosis and eye damage. Methanol metabolizes slowly in the body, and long-term consumption of alcohol with excessive methanol content can cause chronic health hazards.
3. Homemade yogurt
┆ safety hazards ┆ bacterial food poisoning
Many people believe that commercially available yogurt contains many food additives, and homemade yogurt is safer and more assured. Generally speaking, homemade yogurt is not a big problem. Consumers can buy yogurt machines, yogurt starters, etc. on their own. However, if the fermentation conditions are not strictly controlled, it is easy to cause bacteria contamination during the operation, and even cause bacterial food poisoning.
4. homemade fermented soy
┆ ┆ security risks of botulinum toxin poisoning
many people prefer home-made tofu, bean sauce, tempeh, fermented bean curd and so on. Since these homemade foods are often fermented by natural bacteria in the air, contamination by bacteria is prone to occur during the production process. Once contamination by pathogenic bacteria occurs, it will lead to poisoning, the most common of which is botulinum toxin poisoning. Botulinum toxin is a neurotoxin secreted by Clostridium botulinum. It is the most toxic substance among known biological toxins and chemical toxins, with a very high lethality rate.
5. homemade enzyme
┆ ┆ security risks of pollution and pathogens harmful chemicals exceeded
enzyme products more popular in recent years, many businesses have claimed their detox, weight loss, anti-aging and other health effects, a lot of health, “up to” have love Homemade enzymes. Regardless of whether it is indeed effective, self-made enzymes have certain safety hazards. First of all, due to limited conditions, pathogenic bacteria are easily mixed during the production process. After eating, it can cause vomiting and diarrhea, and life-threatening. Secondly, when making enzymes, the time and temperature of each stage of fermentation cannot be precisely controlled. The types and quantities of microorganisms in the fermentation products, as well as the types and contents of metabolites are difficult to determine, and it may also produce harmful substances such as nitrite and methanol. Chemical by-products.
6. homemade pickles
┆ ┆ security risks excessive nitrite
pickles crisp and refreshing, is a popular homemade fermented foods. Making kimchi can easily produce nitrite by natural fermentation. After marinating for a week, the nitrite content gradually decreases. Eating “extremely pickled” kimchi with a short pickling time is likely to cause nitrite poisoning. Ingestion of 0.2 to 0.5 grams of nitrite in adults can cause poisoning, and ingestion of 3 grams can cause death. In addition, after nitrite enters the human body, it can produce nitrosamines, a strong carcinogen.
“Seven Notes” for Homemade Fermented Food
1. Make sure the quality of raw material
production of fermented foods, raw material quality and safety is a prerequisite. The raw materials should be fresh and pollution-free, and moldy raw materials must not be used. For some moldy raw materials, do not continue to use them after washing or removing the moldy parts.
2. The apparatus used sterilized
before the operation, should be strictly used for the fermentation process equipment, containers for disinfection, and to ensure that the fermentation environment and the operator hands clean.
3. good materials handling
raw fruits and vegetables to be cleaned, disinfected, milk, soy products to be sterilized by heating, cooled, into the fermentation vessel.
4. Select quality, reliable bacteria
during fermentation homemade food, the best selection of specific species. For example, the fermentation of yogurt is mainly done by Lactobacillus bulgaricus and Streptococcus thermophilus. These two bacteria can multiply in milk at a suitable temperature and decompose lactose into lactic acid. Choosing a starter containing these two bacteria can ensure the fermentation of yogurt. Some starters also contain some probiotics, which is also a good choice.
5. Note the time eating
a lot of people think that fermented foods are not bad, long-term storage, wine storage longer the more fragrant. In fact, fermented food has a suitable edible period. Insufficient or too long fermentation time will not only affect the flavor, but may also cause food safety problems. For example, homemade kimchi should be marinated for at least 10 days before eating, otherwise it is prone to nitrite poisoning. Generally, self-made fermentation products should not be stored for a long time. If you need to store it for a long time, you should be extra careful about contamination by bacteria.
6. reasonable treatment finished
after fermentation mature, to deal with the finished product scientifically. The suitable storage conditions for different fermented products are different. For example, some finished products must be immediately suspended after fermentation to continue fermentation; some finished products need to be quickly cooled and sealed and refrigerated; some finished products are accompanied by a large amount of gas, so ensure that the exhaust measures are reasonable.
7. Pay attention to the properties of the finished product
When the fermentation is completed and before each consumption, the color, smell, and shape of the fermented product should be carefully observed, and the taste and texture should be tasted. Once abnormality is found, it should be discarded immediately.