Biochemistry paper

In my consumption life, eating is the first. In order to maintain life and health, human beings swim.

In order to grow and engage in all kinds of labor, we must take in all kinds of nutrients and calories from food every day. Therefore, food

must

Meet the requirements of three basic rates: it has certain nutritional value+people's favorite color, fragrance and taste, and is harmless to human body. but

The food opposite.

These two basic requirements of crystal are restricted by the pure chemical composition and physical and chemical properties of food.

The ingredients and energy substances necessary for the normal function of human body in food are called nutritional ingredients. Contains nutrients

thing

Materials are collectively referred to as food. Processed food is also called food, so all foods are usually called food. According to our country

about

Eating habits, food can basically be divided into two categories, one is the staple food (such as rice, flour and its processed products), its main business.

rise

One kind of food is carbohydrate and the other is non-staple food, which can be roughly divided into three categories; Plant food, animal food

、

Processing and manufacturing food. Plant foods are mainly vegetables and fruits. Its nutrients are mainly carbohydrates for survival.

Vegetables (mainly vitamin C) and minerals (calcium, magnesium, potassium and sodium). Animal foods include meat, poultry, eggs and water.

Protein, fat and fat-soluble vitamins (A, O, E) are the main nutrients in dairy products. manufacturing industry

There are many kinds of food, such as sugar, tea, cakes, candy, bean products, edible vegetable oil, processed meat,

Eggs, aquatic products, vegetables, fruits and various blends. In addition to the above nutrients, but also because in food processing

shop

Some unnatural ingredients are inevitably introduced during transportation and transportation. Such as food additives and pollutants. these

raw material

We should also participate in or interfere with the metabolism and physiological functions of the human body to varying degrees.

There are often dazzling, colorful and dazzling foods on the market. Look at red, orange, yellow and green.

Green,

Blue and purple foods often make people salivate and have an appetite.

So how did the attractive color come from?

All kinds of colored substances in food are collectively called pigments, which can be divided into natural pigments and synthetic pigments.

According to source classification, natural pigments can be divided into three categories according to solubility: animal pigments, plant pigments and microbial pigments.

be divided into

Fat-soluble pigments and water-soluble pigments. According to the different chemical structures, it can be divided into pyrrole pigment, polyene pigment and phenol color.

Sue,

Pyridine pigments, quinine pigments and other kinds of pigments.

Natural pigments are generally sensitive to light, heat, acid, alkali and other conditions, and often fade during processing and storage.

. Synthetic pigments generally have different degrees of toxicity. Synthetic pigments are usually brighter and stronger than natural pigments.

Big and natural

Stable, strong coloring power, and can be adjusted at will, with relatively low cost. But synthetic pigment itself has nutritional value.

The last paragraph of food biochemistry 3 12

At present, there are about 50 kinds of pigments used as food in the world, and the number of pigments allowed in different countries is different.

. According to the hygienic standard GB276086 for the use of food additives in China, synthetic pigments are allowed in China.

There are eight kinds of pigments, namely amaranth, carmine, lemon yellow, sunset yellow, indigo, bright blue, crimson and new red. these

The pigment has good coloring effect and high safety factor.

However, most synthetic pigments are directly harmful to human body or harmful substances produced during metabolism.

"online search"

Food biochemistry 3 17

Food flavor is a sensory phenomenon, which is a sensory synthesis that gives oral touch, warmth, taste and smell.

. Flavor substances have many components and few contents. Except for a few components, most of them are easily damaged and thermally unstable.

Outside, most of them are non-nutrients. However, flavor substances can promote people's appetite, thus indirectly affecting nutrition.

(ingestion, digestion) has a great influence. The tastes are sour, sweet, bitter, salty, spicy, fresh, astringent, alkaline, cool and golden.

Ten important tastes, four of which are basic tastes: sour, sweet, salty and bitter. Fourth paragraph

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Food additives refer to substances added in the process of food production, processing and preservation to improve food quality, color and flavor.

Change the structure of food, prevent food from oxidation, corruption and deterioration, and compounds added to food for the needs of processing industry.

Enter matter or heaven.

However, the stakes are high. There are many kinds of food additives with different functions, and some of them have multiple functions. At present, there is no uniform standard for their classification.

. ordinary

According to the use, it can be divided into eighteen categories: preservatives, antioxidants, bleaches, colorants, acidulants, etc.

Food additives, especially chemically synthesized food additives, are often available.

one

Toxicity. Due to the pollution of toxic substances in food additives and the special physiological and metabolic effects of some additives,

change

Products often cause harm and poison to human body.

For example: 1955 Japanese "Morinaga" brand blended milk powder was added with disodium hydrogen phosphate with arsenic content of 3%-9%.

The stabilizer caused "Morinaga arsenic milk" poisoning, 1, 2 1, 3 1 infant poisoning, 1 human death. Therefore,

Chemical food

Additives will be harmful to human body, which will lead to serious casualties.

Most additives are not nutritious, but nutritious additives can't be used in excess, and excessive use will.

Produce toxic effects. Excessive intake of vitamin A can lead to loss of appetite, headache, blurred vision, insomnia and hair loss.

Shoulder and back

There are chronic poisoning phenomena such as rash, dry skin desquamation, cleft lip bleeding, nosebleeds and anemia.

Excessive vitamin D can also cause an increase in serum calcium, total cholesterol and bone marrow calcium.

Therefore, food additives should be carefully purchased and used, otherwise it will lead to serious consequences.

Some foods are not good for human health, except for nutritious parts and some parts that may not have nutritional functions.

Kang's part is called taboo ingredient. These ingredients come from food raw materials themselves, food processing, microbial pollution and

Environmental pollution and so on. When the harmful ingredients in food exceed a certain limit, it will do harm to human health.

1, phytotoxin; For example, ricin: people and animals eat castor seeds or oil, ranging from vomiting and diarrhea to serious illness.

And die. The toxin component in castor is ricin, which is extremely toxic, and the minimum lethal dose to mice is 1g/kg.

Weight.

2. Animal toxins;

In addition, there are toxins in animal foods, and almost all of them are toxic animal foods.

Belonging to aquatic products. It is known that 1000 kinds of marine life are poisonous or can secrete venom, many of which are edible.

or

Can enter the food chain. The toxin components of these aquatic animals can be divided into two categories: fish toxin and shellfish toxin. fish

For example:

Tetrodotoxin is one of the most detailed fish toxins, which mainly exists in ovary, liver, intestine and skin.

and

Most of the puffer fish in eggs, whether fresh water or seawater, are poisonous. The muscles of puffer fish are generally nontoxic, but some puffer fish muscles.

Toxic.

Tetrodotoxin is a kind of amino-hydrogenated m-diazonaphthalene, which is colorless crystal and can be dissolved in acidic solution and 60% ethanol.

Solution, slightly soluble in water, insoluble in other organic solvents, unstable below pH7 and PH3, decomposed into tetrodotoxin, but toxic.

Does not disappear and is heat-resistant.

Tetrodotoxin specifically blocks the flow of sodium ions necessary to produce nerve impulses to nerve or muscle cells, making

Nerve endings and nerve centers were paralyzed and died. Meat fish often appear after eating pomfret, sea bass and other fish.

Poisoning like poisoning of this nature is related to the food chain of fish. Most toxins come from blue-green algae. Herbivorous fish use toxic algae.

Later it can indirectly enter the body of carnivorous fish. The molecular formula of this toxin is C35H65NO8. The LD50 value of mice is

80vg/kg body weight. The poisoned person died of cardiovascular system failure. Feeding on certain herring, silver carp and northern carp.

Barracuda and other fish can also cause poisoning.

3. Many microorganisms that pollute food will produce toxins harmful to people, animals and animals, some of which are carcinogens and dramas.

Poison.

Mold belongs to fungi, and mycotoxin is also a part of mycotoxin. In terms of fungi in a broad sense, some

Metabolites produced during the growth and reproduction of fungi; There are also some fungi that can make some ingredients in food toxic.

Things. So simply speaking, mold mainly refers to the production of toxic metabolites in the food it pollutes. Such as: Huang

Aspergillus is a hepatotoxic metabolite produced by a few strains of Xanthomonas and parasitic Aspergillus. Spores of this mold

Cloth is extremely wide, especially in the soil. Aflatoxin B 1 is the most common and toxic, and its LD50 value to dogs is

0.5- 1.0mg/kg body weight. Many animal experiments (fish, birds, mammals) have proved that aflatoxin is

One of the extremely strong carcinogens, although different kinds of animals have different sensitivities to acute poisoning, it is still

No animal can completely counteract aflatoxin, because toxicity and carcinogens mainly act on the liver.

4. Salmonella toxin, staphylococcal enterotoxin and botulinum toxin are the main bacterial toxins that contaminate food.

. There are many unknown bacterial toxins that also exist in food.

Staphylococcus aureus is a common skin and epidermis of human beings and animals.

Only a few subtypes of bacteria can produce enterotoxin, all of which are protein with known components, and their relative molecular weight is.

30000-35000. Symptoms of enterotoxin poisoning generally include salivation, nausea and vomiting, spasm and diarrhea 2-3 hours after eating.

Wait for symptoms. Most patients returned to normal after 24-28 hours, with fewer deaths.

5. The chemical toxins in food mainly come from the pollution of the growth and reproduction environment of food raw materials and the pollution of water bodies by processing machinery.

Due to environmental pollution, food contains chemical toxins for two reasons.

Aspects: First, industrial waste pollutes water, soil and atmosphere, and eventually accumulates in edible animal and plant tissues; The second one is

Pollution of edible animals and plants caused by extensive use of pesticides, fertilizers and growth regulators. The third is heavy money.

Pollution, such as mercury, lead, cadmium and arsenic; Fourth, contact with processing chemicals, such as nitrate and nitrite in food.

Products such as products heated by synthetic and fat oxidants.

At present, there is a big gap between food industry and nutrition in China. Most food companies can only

The most basic requirements of food safety and hygiene. The vast majority of small and medium-sized enterprises pursue market effect and only pay attention to food.

Most of the "color, fragrance and taste" of products are not equipped with nutritionists, nor do they pay attention to nutritional fortification and its effect. Minority number

French food producers even make huge profits from counterfeit and even toxic and harmful foods, which is harmful to people's health. Respond to this

Strengthen supervision and law enforcement, ban.

(1) According to the general principles of international food hygiene, it is defined as ensuring that food is cooked according to its purpose.

It is harmless to consumers when mixed and/or eaten. The food safety here emphasizes the consequences. And food industry base.

The definition of this term GB 1509 1-95 is to prevent food from being produced, harvested, processed, transported, stored and sold.

Every link is polluted by harmful substances including physics, chemistry and biology, which makes food beneficial to human health and texture.

Good measures have been taken. And its synonym is listed as: food hygiene. It can be seen that the food safety here includes

Measures to be taken in the whole food chain from food production to sales. Comply with the Food Hygiene Law of People's Republic of China (PRC).

The legislative purpose of this law (hereinafter referred to as the Food Hygiene Law) is to ensure food hygiene and prevent food pollution and harmful causes.

The harm of vegetarianism to human body ensures people's health and strengthens people's physique.

(2) Food safety hazards. Refers to factors or factors that may damage or endanger the safety and quality of food. These factors

Including biology, chemistry and physics. They can exist in food in various ways, and once these factors or

If these factors are not controlled or eliminated, food will become toxic food that threatens human health.

2 1 century is the century in which people pursue health and longevity. Our people are striving to build a "well-off society in an all-round way"

Work hard for socialist countries. With the improvement of living standards, people's health awareness is stronger and their demand for food is more.

Pay more attention to nutrition. In order to meet the various needs of different people, we are in the camp of staple food, especially traditional staple food.

Strengthening the country has a long way to go.