Now, in summer, the weather is hot and the air humidity is high. Many germs will multiply quickly, and the deterioration of food will be accelerated. Pay attention to preserving food in summer. If food has some bad taste, it should not be used again, so as not to be harmful to human body. Then what will the taste of food be when it goes bad? What are the bad smells of food?

1. The taste of spoiled food

1. Hare flavor

Foods containing more oil for a long time, such as oil, cakes, dried salted fish, walnuts, peanuts, melon seeds, etc., will produce a bitter, hemp, pungent and unpleasant taste, which is commonly known as "Hare flavor" by the people. This is because oil is easily oxidized and rancid, which leads to the production of spicy taste.

2. rancid smell

fish, pork, eggs, tofu, dried tofu and other foods rich in protein are spoiled and will produce rancid smell. Under the action of microorganisms and enzymes, protein will be decomposed into organic amines, sulfides, fecal odorants, aldehydes and other substances, which have a foul smell.

3. Sour taste

Foods rich in carbohydrates, such as grains, sugars and their products, will have their own characteristics of sour taste or bad taste when they go bad. Carbohydrates will decompose to produce monosaccharides, disaccharides, organic acids, alcohols and aldehydes, so they will produce sour taste or wine taste. Rice turns sour, cakes turn sour and fruits rot.

4. musty smell

food contaminated by mold, such as grain, peanuts, bread, cakes, rice, steamed bread and so on, often goes moldy and goes bad in warm and humid environment. Mold may produce toxins, such as aflatoxin, which we are familiar with.

5. ammonia smell

dried aquatic products such as pickled fish, dried shrimps, dried shrimps, shredded squid, scallops and dried fish. If dried aquatic products such as dried shrimps are stored for too long, there will be an obvious ammonia smell and the color will turn pink. This is mainly because the protein contained in them is decomposed into peptides and amino acids by microorganisms, and then further decomposed into lower amines and ammonia. Lower amines are not only toxic, but also easy to combine with nitrite in aquatic products to form a strong carcinogen-nitrosamines. If the above food is found to have ammonia smell or other peculiar smell, it should be resolutely thrown away, because even after being washed with water, it cannot be safely eaten.

2. Harm of eating spoiled food

1. Moldy peanuts, corn, rice and products: contain a large amount of aflatoxin, which can cause fever, vomiting, jaundice, coma, spasm and even acute poisoning death. Yellow koji toxin has high temperature resistance, strong carcinogenicity, especially destructive power to the liver. Therefore, it is best to store the purchased grain in a ventilated, dry, low-temperature and oxygen-deficient place, and do not eat it if it is moldy.

2. Deteriorated fish, shrimp and crab: Enzymes produced by some bacteria, yeasts and molds will decompose protein in aquatic products after death, producing toxic substances such as amines, ammonia and hydrogen sulfide, which are manifested as skin flushing, conjunctival congestion, chest tightness, headache, vomiting and diarrhea when poisoned. When the fish eyes are cloudy, the scales are dim, and the shells of shrimps and crabs are red, that is, they are not fresh.

3. moldy sugarcane: mainly manifested as dull skin, gray color, soft texture, light brown pulp, musty or sour taste. Mildew-induced toxic fungi in sugarcane, namely Corynebacterium saccharum, can produce neurotoxins, which mainly damage the central nervous system. After eating, digestive dysfunction and nervous system symptoms appear one after another, and patients often die of respiratory failure.

4. Unsanitary self-made fermented food: The self-made fermented food such as stinky tofu and bean paste is not heated or fully heated when it is eaten due to poor sanitary conditions, long storage time and anoxic environment, which causes Clostridium botulinum to produce botulinum toxin and cause poisoning. Symptoms such as blurred vision, unclear speech, pupil dilation, muscle paralysis, respiratory failure, etc. occurred until death.

5. Locally rotten apples: We often like to cut off the bad parts of apples before eating them. In fact, the whole apple has been polluted by bacteria and deteriorated, but it has not shown rotten phenomenon for the time being. When eating it, it will feel bitter and even have poisoning phenomena such as nausea and vomiting.

6. sweet potato with long spots: sweet potato is easily attacked by black spot when it is stored for too long, damp and broken, which makes the epidermis grow brown or black spots, or dry and concave, and the potato heart becomes hard and bitter. The toxin contained in sweet potato is heat-resistant, so eating raw or cooked sweet potato with dark spots will cause poisoning, nausea, vomiting, abdominal pain, diarrhea and other symptoms, and even cause fever, asthma, convulsions, coma and even death in severe cases. Therefore, once the sweet potato has dark spots, hardness, bitterness and mildew, don't eat it again.

7. Rotten ginger: Rotten ginger produces a highly toxic safrole. After eating, poisoning causes damage to liver cells, and even induces serious consequences such as esophageal cancer and liver cancer. Therefore, be sure to buy dry ginger that is not rotten or even stale. Keep it dry and free from frostbite during storage.

8. Rootless bean sprouts: Generally, when you grow soybean sprouts and mung bean sprouts, you only need to filter clear water and keep warm every day, but we will also see some fat rootless bean sprouts in the market, and some chemicals will remain in these bean sprouts, which will cause poisoning if you eat them in large quantities for a long time. You can buy relatively safe "stupid" bean sprouts, or try to grow some bean sprouts yourself.

3. Can you still eat it after boiling?

Food will go bad if it is not properly preserved. Many people think that spoiled food can be eaten after boiling, which is wrong.

The toxin secreted by bacteria before entering human body is very resistant to high temperature and is not easy to be destroyed and decomposed.

Therefore, it is unscientific to treat spoiled food by heating and pressurizing. The spoiled food must be thrown away, and never lose too much for too little.

4. How to prevent food from spoilage

1. Low temperature storage method

Low temperature storage method is a common method for storing cooked food. Its main principle is to effectively inhibit the growth and reproduction of microorganisms through low temperature, reduce the activity of enzymes, weaken the chemical reaction in food, and better maintain the original flavor and nutritional value of food.

according to the different temperatures, low-temperature storage can be divided into refrigeration method and freezing method, and the refrigeration temperature is above freezing point.

The foods that are refrigerated mainly include vegetables, fresh meat, fresh fish, fruits, dairy products, cooked products and semi-finished products. Freezing method is to freeze food in an environment below freezing point, which is suitable for storing animal food. Freezing can keep food for a long time without spoilage. But after long-term storage, although the quality of food has not changed much. However, with the decrease of moisture, its back-nourishing value is reduced, and it tastes bad. In addition, when more than two kinds of food are stored in the same freezer, they should be sealed and isolated with non-toxic food bags. Prevent odor from polluting each other. At the same time, it can also reduce the loss of water in food.

second, high-temperature storage method

high-temperature storage method is often used in the catering industry to store food, because microorganisms have weak tolerance to high temperature, and can effectively kill microorganisms when the temperature increases. And destroy the activity of the enzyme. It can prevent the influence of microorganisms on food and achieve the purpose of storing food. The method is to first boil or steam the food thoroughly (reaching a high temperature above 111 degrees), and then take it out or soak it in the original soup. Keep it in a cool and ventilated place without stirring to prevent food from being contaminated again. This method can keep food from spoiling for a long time. This method is suitable for the preservation of finished and semi-finished products of animal foods, as well as dried foods such as water.

third, ventilation storage method

ventilation storage method is mainly suitable for preserving grain, dry food and food that needs air drying. They are all characterized by fear of mildew and cover. For example, rice, noodles, peanuts, vegetables and other foods need ventilation when stored. This can make mold difficult to grow, keep the original ingredients of food and reduce mildew.

Fourth, the vacuum sealing preservation method

The vacuum sealing preservation method is to keep food in a vacuum state from contacting with microorganisms in the air. A method of sealing and preserving food, such as canned products and vacuum-packed products. This method is suitable for the preservation of various foods.

with the continuous development of science and technology, there are more and more methods to store food, such as nuclear radiation storage method and modified atmosphere

method. Their main principle is to control or kill microorganisms growing in food and delay the metabolism of internal tissues of raw materials, so as to prolong the storage time of food, improve the storage quality and achieve the purpose of preservation.