2, beef avoid chestnuts, the same food will cause vomiting.
3, mutton avoid watermelon, the same food will hurt the body.
4, dog meat avoid mung beans, the same food will be poisoned.
5, rabbit meat avoid celery, the same food will cause hair loss.
6, chicken avoid celery, the same food will hurt the body.
7, geese avoid eggs, the same food will hurt people.
8, turtle (also known as foot fish) avoid amaranth, the same food will be poisoned.
9, carp avoid licorice, the same food will be poisoned.
10, crabs avoid persimmons, and eating them together will cause diarrhea.
1 1, eggs avoid saccharin, and they will be poisoned and even die if they are eaten together.
12, brown sugar avoid preserved eggs, with food will be poisoned.
13, white wine should avoid persimmons, and eating together will be boring.
14, onions avoid honey, and eating together will hurt your eyes.
15, radish avoids fungus, eating the same food will cause dermatitis.
16, tofu avoids honey, and the same food will make you deaf.
17, potatoes avoid bananas, and eating together will cause long spots on the face.
18, bananas avoid taro, and eating together will cause bloating.
19, peanuts avoid cucumbers, and eating together will hurt your health.
20, sweet potatoes avoid persimmons, and the same food will get lithiasis.
Food collocation taboo.
1, milk and broccoli are similar-eating together will affect the absorption of calcium.
2, carrots and white radishes are similar-the same food affects the absorption of vitamin C.
3. Turtle and celery are very similar-eating together will denature protein and affect nutrient absorption.
4, coriander and cucumber are similar-the same food destroys vitamin C.
5, vinegar and pumpkin are similar-eating acetic acid together will destroy the nutrients in pumpkin.
6, Flammulina velutipes and donkey meat-the same food is easy to induce angina pectoris.
7. Pumpkin and rape are very similar-eating at the same time will reduce the nutritional value.
8. Crucian carp and wax gourd are very similar-eating together reduces the nutritional value.
9. tomatoes and cucumbers are like grams-the same food destroys vitamin C.
10, celery and chicken are very similar-eating together reduces the nutritional value.
1 1, bamboo shoots and mutton are very similar-eating together can easily lead to abdominal pain.
12, Chinese cabbage and rabbit meat-high quality protein were destroyed at the same time.
13, carp and dog meat are very similar-eating together will produce substances that are not good for the human body.
14, snails and pork are very similar-the same food hurts gastrointestinal function.
15, honey and crab meat are the same-eating together reduces the nutritional value.
16, potatoes and sparrow meat are very similar-the same food makes the face pigmentation.
17, shrimp and jujube are very similar-the same food can be converted into arsenic, which is very toxic.
18, tomatoes and potatoes are very similar-the same food will cause abdominal pain and diarrhea.
19, honey and onions are very similar-eating together can lead to bloating and diarrhea.
These are all chemical reactions. Report.
Cooking is scientific. As far as the chemistry involved is concerned, it can be briefly summarized as follows:
1, do not wash rice too often.
2. Wash the vegetables before cutting them, and then stir-fry.
3, correctly grasp the temperature
4. Add monosodium glutamate to the dish before cooking.
5, when cooking fish, cooking wine and vinegar should be put early.
6. The oil should be cooked.
7. The carrots and meat are cooked.
8. Try not to pickle or steam food.
Cooking chemistry is a young discipline derived from general chemistry and food biochemistry. Studying and discussing the chemical composition of cooking raw materials and the chemical phenomena of mutual reaction and change during cooking is an important basis for further understanding cooking processing and cooking nutrition and hygiene. Simply put, the so-called cooking refers to cooking, which is the so-called cooking.
First, the role of cooked food.
Cooked food plays an important role in human evolution. Cooked food shortens the digestion process, expands the variety of food (from wild fruit to meat), and promotes the formation and development of human physical strength and intelligence, especially the brain. The main functions of cooked food are decomposition, detoxification, sterilization and flavor enhancement.
1. Decompose cooking food, mainly to convert the original macromolecules into smaller molecules, so that it is easy to digest and absorb in the body. The so-called "cooked" is judged by experience, which means that you can eat without feeling "raw".
2. Detoxification heating can decompose harmful substances in some foods, such as antitrypsin in soybeans and eggs (which hinders the activity of trypsin in the human body) and cyanide in almonds.
3. Sterilization Generally speaking, food, especially vegetables, contains a large number of pathogens, parasite eggs and various bacteria introduced during storage due to fertilizer. Although it is not clean after washing, it can be killed by heating and boiling for 3 to 5 minutes. In particular, infectious bacteria in the digestive tract must be heated to be eliminated.
4. Seasoning can improve color, aroma and taste by heating, produce new and more nutritious compounds, and improve the quality of food.
Second, cooking methods
According to the types of food (staple food or non-staple food, meat or vegetables) and eating requirements, there are mainly two kinds: dry method and wet method.
1. Wet cooking refers to the floorboard of boiling, steaming, stuffy, stewing, simmering and boiling. Among them, boiling, steaming and stuffy are mainly used for the processing of staple foods such as rice and noodles, and are also suitable for the cooking of meat and fish. Damp heat is characterized by less fire, more water and longer time. More distinctive is:
(1) Slow fire. First, soak food (such as meat) in cold water with good seasoning and heat it slowly. Gravy, fat and protein gradually ooze from the surface of the meat, leading to meat rot and rich nutrition in the soup. For example, the eight diagrams soup in Wuhan (with soft-shelled turtle or tortoise as the main raw material) is a famous product of this cooking method.
(2) long, long, rinse. The similarity of these three methods is to boil the soup first and then put the food in it. This can solidify the protein on the surface of food and keep most of the fat and protein in it. Its characteristics are short cooking time, light soup, crisp and delicious. Compared with blanching, blanching takes a long heating time, generally reaching 89% maturity, and is mostly used for vegetables. When cooking meat, it is called rinse, which requires good knife work and thin cutting, such as instant-boiled mutton in Beijing.
(3) braise. Cook the meat, fish and other foods, in order to appropriately increase the consistency of the soup, use a small fire (about 85℃) to heat the water and slowly evaporate the juice to make the soup thick, reddish brown in color and mellow in taste.
2. Dry burning includes roasting, burning, smoking, frying and frying. Among them, baking is often used for pasta (such as toast and sesame seed cake). Except fish and meat, all kinds of dry frying are generally used for cooking. It is characterized by large fire (called martial fire), little water and short time. Stir-fry with oil and seasoning first, then add vegetables and turn over quickly. Protein, fat and inorganic salts are mostly left in the dish, and only a small part is added to the soup, but some vitamins are lost. Attention should be paid to coke prevention in dry burning. Because tryptophan in protein decomposes after the meat is burnt, it will cause food poisoning. So burnt vegetables are not suitable for eating. Besides, if the fire is too big, there will be a strange smell in the oil. This is because when the temperature is too high, glycerol produced by fat hydrolysis is decomposed into acrolein (used as tear gas in the military), which is volatile and toxic.
3. Microwave heating method is characterized by using microwave as heat source instead of fire or electric heating. Microwave is a kind of high frequency electromagnetic wave, which will not cause ionization. It can be enclosed in the metal wall of the furnace box to form an electromagnetic wave emission system similar to a small radio station. The microwave energy field emitted by the magnetron constantly changes direction, forming a positive and negative alternating electric field around food molecules like a magnet, so that the positive and negative poles and positive and negative ions contained in food are reversed, which causes intense and rapid vibration or oscillation. When microwave is used, this oscillation can reach 2.5 billion times per second, causing a lot of friction heat in food. The highest temperature can reach 200℃, and water can be boiled in 4 ~ 5 minutes. Its heating temperature, speed and uniformity are determined by the characteristics of the food itself, and it has high efficiency for foods with high sugar content and oil content. The depth of action is 2 ~ 3.5 cm, and the size of food should generally not exceed 5 cm. Its characteristic is that microwaves act simultaneously from all surfaces, top and periphery, so the uniformity is good.
Pottery, porcelain, cardboard, plastic film, glass and other containers can be used as microwave heating appliances without heating themselves. Aluminum, stainless steel and other metals or some plastic containers cannot be used to heat food, because they will reflect microwaves, causing sparks to splash and the containers to get hot.
Third, the knife method and temperature
Cooking techniques are very particular about knife skills and heat, and there are many chemical reasons.
Skilled chefs quickly cut the whole piece of lean meat into shreds, with measured length, width and thickness, even and neat. Different dishes, one piece at a time, one piece at a time, are all exquisite. On the stove, the chef grasps the temperature, races against time, turns several times, knocks a few times, and shovels just right. Burning, boiling, frying and frying have their own tastes. ? Quot tender should be tender, crisp should be crisp, and crisp should be crisp. "Cook and then uncover the lid. "
We all have this experience in life: a piece of rock sugar dissolves in water much slower than a spoonful of soft candy. If the rock sugar is ground into powder in advance, the dissolution rate will be much faster. When cooking, everyone likes to use powdered salt instead of coarse salt with large particles. The difference between large particles and fine powder of sugar or salt is mainly the size of surface area. Vegetables and meat are cut into filaments, which increases the surface in contact with water. Nutrients are easily soluble in water and some chemical changes are easy to carry out. Stir-fried meat slices are faster than large pieces of stew, also because the surface area increases and there are more opportunities for heating. The speed of chemical reaction is closely related to the surface area of substances in contact with each other. There is a theory in chemistry that explains the speed of chemical reaction called molecular collision theory. Only through effective collision can chemical reactions occur between substances.
The so-called stress on temperature mainly refers to controlling the size of firepower, mastering the length and timing of heating time, and in the final analysis, controlling temperature. Temperature is one of the important conditions of chemical change. The same spoonful of sugar doesn't dissolve as quickly in cold water as in boiling water. Noodles can only be cooked in a boiling pot. Increasing the temperature usually accelerates the dissolution and chemical reaction. When boiling water, the temperature of the water will gradually increase. Under the standard air pressure (10 1325pa), the boiling temperature of water is 100oC. Keep heating, no matter how big the firepower is, the temperature will not rise after drying. When stewing meat, after boiling, keep it boiling with slow fire. The flavor of meat is mainly due to the cleavage of peptide bonds in protein to produce amino acids. You can't cook the meat in advance in a hurry with strong fire. If the pressure cooker is used, the boiling temperature of water can be increased to above 120oC, which can greatly shorten the time required for stewing meat. The temperature of the oil pan can reach 200 ~ 300 oc, so stir-fry the shredded pork in the oil pan quickly, or it will burn. Amino acids become "charcoal" after coking. When traveling on the Qinghai-Tibet Plateau, water will boil when the temperature rises to 80 ~ 90oC. Under this condition, frying oil cakes and making pancakes is ok, while cooking requires a pressure cooker.
Fourth, cooking AIDS.
Including additives and condiments for staple food and non-staple food processing.
1. additive
(1) Yeast powder (filler) Yeast powder is used to make steamed bread, bread and cakes. Its function is to neutralize the acid produced by fermentation and make the product bulky by foaming. The main component of baking powder is a mixture of sodium bicarbonate (baking soda) and some acidic salts (such as potassium hydrogen tartrate and sodium dihydrogen phosphate). The former is used to neutralize the acidic components in the batter and generate carbon dioxide, while the latter can prevent the generation of overbased sodium carbonate. The principle of action is that starch is converted into sugar by amylase in yeast, and then glucose is converted into carbon dioxide by Saccharomyces cerevisiae. The further expansion of carbon dioxide gas will form soft porous substances and produce a small amount of alcohols and esters, making food soft and delicious. Because fresh yeast is slow and difficult to control, baking powder is used.
(2) Tenderizing agent Tenderizing agent itself is a kind of hydrolase, and it is an additive before cooking hard-cooked meat (such as beef, especially beef stomach, etc.). ). It can accelerate the hydrolysis of food at room temperature and catalyze the cleavage of peptide chain in protein. Due to the action of this enzyme, the time required for food to reach the same "boiling" degree is greatly shortened, which is especially effective for connective tissues such as collagen and elastin (beef tendon), and also has a certain effect on myofibrillar protein. The main meat tenderizer is papain or fungal (microbial) protease. Typical tenderizers for beef surface treatment are 2% commercial papain or 5% fungal protease, 15% glucose, 2% monosodium glutamate (monosodium glutamate) and salt.
(3) Stabilizers, thickeners and anti-caking agents can increase the viscosity of some fat or liquid foods (such as juice), mostly polysaccharides, whose molecular structure contains multiple hydroxyl groups. Because hydroxyl group is easy to form hydrogen bond with water, it can prevent water from separating from less polar fat, and can emulsify water and oil to make them mix more evenly in food. The commonly used stabilizers and thickeners are D- sorbitol and D- mannitol, which are especially effective for candy and cheese. Also used as humectant, sweetness control agent and softener. Another additive (such as magnesium silicate) can combine with water (crystal water) to prevent food from caking due to moisture, which is called anti-caking agent.
Step 2: Seasoning
Including seasoning in cooking and auxiliary materials in eating.
(1) Seasonings are usually divided into oil-soluble and water-soluble. The former is suitable for high-temperature frying pan, that is, it is added first when the oil is heated to release fragrance or other fragrance; The latter is small in molecular weight and volatile, so it should be added after cooking. The main seasonings are:
① general seasoning. Such as star anise, pepper (oil soluble), onion, ginger, garlic, pepper, pepper, sugar, monosodium glutamate, salt (water soluble) and so on. They not only have flavor and fragrance, but also have bactericidal effect (for example, allicin is heated or produced by enzymes in digestive organs, which has strong bactericidal power) and contain many vitamins (for example, onions contain a lot of vitamin B). There are dry powder seasonings such as ginger powder, onion paste and pepper in the market.
② Other seasonings. Mainly wine, vinegar, soy sauce and so on. Wine is often used to remove fishy smell (wine can dissolve and volatilize trimethylamine in fish); Vinegar is mainly used for sterilization (especially influenza and other viruses), dissolution of fishbones and bones (promoting phosphate dissolution and absorption of calcium and iron in the body), deodorization (fish and fish cutting tools can be scrubbed with vinegar to remove the unpleasant smell caused by furan, fusel and sulfide), alkali removal and increase gastric acid. Esterification of wine and vinegar can produce aroma; Soy sauce is not oil, but an aqueous solution of several amino acids, sugars, aromatic esters and salts, which are mainly used as flavoring agents and colorants. Soy sauce can be divided into brewing soy sauce and chemical soy sauce. Our ancestors could brew soy sauce as early as 3000 years ago. It was first brewed with animal proteins such as cattle, sheep, deer, fish and shrimp, and later brewed with plant proteins such as potatoes and grains. Brewed soy sauce contains not only rich amino acids, but also aromatic esters, organic acids, ethanol, pentose and methyl pentose, which show bright reddish brown when combined with amino acids. Chemical soy sauce is made by decomposing protein in soybean into single amino acid with hydrochloric acid, and then neutralizing and coloring. Solid soy sauce is made by steaming the water in soy sauce under low pressure. It is a delicious condiment unique to China and sells well all over the world.
Supplementary information of whistleblower 2009-09-22-09:142) Accessories are generally not eaten directly alone, but usually cooked into solid or liquid products that can be used to improve the taste of meals. Mainly includes:
1 pepper and salt. It is made by mixing 500 grams of Zanthoxylum bungeanum and 150 grams of salt, which is usually used with pickled mustard tuber.
② Zanthoxylum oil. Burn sesame oil to 70% maturity, add pepper and stir-fry until dark red, and take out pepper. 15g Zanthoxylum bungeanum is used in 500g oil, with good fragrance and color;
③ Chili oil. First, mix 200g of Chili noodles with100g of cold boiled water to make thick porridge, then burn 600g of sesame oil to 80% maturity, then pour it into the prepared Chili porridge and stir it into red oil.
④ onion ginger oil. Heat 1000g peanut oil or lard to 40% heat, add 100g ginger slices, add 100g onion slices (inch long), stir-fry until golden and fragrant, and take out the onion ginger.
⑤ Clear soup. There are two types: ordinary type and advanced type: the former is to put the old hen and pig bones into a cold water pot, boil them with strong fire, skim off the floating foam, simmer for a long time with slow fire, take out the bones and filter out the bone residue with gauze; The latter is to peel and chop the chicken leg meat into minced meat, put it into the filtered soup with onion, ginger and cooking wine, heat it with strong fire and stir it in the same direction with a spoon. When the soup is boiling, use slow fire (don't boil) to make the residue in the soup adhere to the minced chicken, float out of the soup, and skim it off with a spoon.
6 milk soup. Put the bone in a cold water pot, bring it to a boil, and skim off the blood foam on it. Then add onion, ginger, cooking wine, etc. Continue to cook over medium heat until the soup is milky white.
7 soup. Put the bones in a pot, add clear water until the raw materials are just immersed, boil them with strong fire, skim off the floating foam, and cook them with slow fire for 2-3 hours to completely dissolve the umami flavor of the raw materials in the soup stock to obtain broth;
8 Various sauces. Such as bean paste. Usually, beans such as broad beans and soybeans are fermented and cooked into paste, and mixed with caramel, Chili oil and soy sauce. Another example is the famous fried sauce in Beijing, which is made by mixing oil with soy sauce and starch, and then adding sweet noodle sauce diluted with water to the wok.
2.3 Color, taste and chemical composition
With the progress of science and technology and the improvement of living standards, people pay more and more attention to the color and fragrance of food in their diet, so as to achieve the purpose of pleasing their mood, stimulating their appetite and improving their quality of life.
First of all, the color of food
It is found that there are three kinds of pigments that can be used in food: natural pigments, synthetic pigments and artificial coloring substances.
1. Natural food pigment
Refers to the original natural color source of flowers, fruits and plants. Commonly used natural edible pigments mainly include:
(1) Monascus pigment. It is a liquid red pigment obtained by soaking monascus rice with ethanol, or a crystal refined by crystallization from the submerged culture solution of monascus. The pigment has good light resistance and heat resistance, and is not affected and interfered by metal ions, various oxidants and reductants. Tone is not as easy as ordinary natural pigments to change significantly with PH value. For example, red rice is made by soaking indica rice or glutinous rice in water, steaming, and then adding red rice for fermentation, which can be directly used for making and coloring sausage, red fermented bean curd, various pickles and cakes.
(2) curcumin. Yellow pigment extracted from turmeric stem is a hydroxyl compound with three double bonds. This product has strong coloring power and reduction resistance, but poor light resistance, heat resistance and iron ion resistance. Because it is too spicy, except curry powder, it is not suitable for direct use.
(3) shellac pigment. It is a red component in the raw gum secreted by lac insects, and it is easy to form lakes with various metal ions. Stable to light and heat under acidic conditions. The color changes with the pH of the medium: pH < 4.5, orange; 4.5 ~ 5.5, red; > 5.5, purplish red. It is suitable for coloring acidic foods such as fresh orange juice, red juice, canned red fruit and orange flavor dew.
(4) beet red. The red aqueous solution extracted from purple beet is red or purplish red after concentration, which is stable under acidic conditions and has good coloring power, but poor light, heat and oxidation resistance.
(5) safflower yellow pigment. Extracted from safflower, soluble in water. It is bright yellow at pH 2 ~ 7 and red when alkaline. Light resistance, heat resistance and microbial resistance are good, but heat resistance and coloring power are poor, and it is grayish black when it meets iron. Mostly used for coloring cold drinks, candy, cakes, etc.
(6) beta-carotene. Extracted from carotene, orange-red, polyene compound with 9 double bonds. It is an oil-soluble substance with stable performance, and is often used for coloring meat and its products.
2. Synthetic food pigment
Due to toxicological reasons, the use of synthetic food pigments is restricted and is constantly being eliminated. At present, the following five types are mainly used:
(1) Amaranth red. Purple powder, soluble in water and polyol, insoluble in oil. It has good light resistance, heat resistance, salt resistance and acid resistance, but its disadvantages are poor antibacterial, oxidation resistance and reduction resistance, so it is not suitable for fermented food. The national health standard stipulates that the maximum dosage is 0.05g per kilogram.
(2) carmine. Crimson powder, soluble in water and glycerol, insoluble in oil. Good light resistance and acid resistance, brown under alkaline conditions, but poor heat resistance, oxidation reduction resistance and antibacterial properties.
(3) lemon yellow. Yellow powder is widely used all over the world. Soluble in water and glycerol, insoluble in oil. Good heat resistance, light resistance, salt resistance and acid resistance; Poor oxidation resistance and reducibility, fading after reduction, slightly red when exposed to alkali.
(4) The sun sets yellow. Orange powder, soluble in water and alcohol, insoluble in oil, turns red-brown when it meets alkali; Poor reduction resistance, fading after reduction.
(5) Indigo. Pink blue is widely used in many countries. Soluble in propylene glycol and glycerol, poor in water solubility, insoluble in oil, strong in coloring, good in light, heat, acid and alkali resistance, but poor in redox resistance and antibacterial performance.
China stipulates that the above pigments can be used in fruity water, fruity powder, sherbet, soda, colored wine, candy, cake, canned food and so on. , and the dosage should generally not exceed 0. 1g/kg.
3. Artificial pigment
Although there are many kinds of artificial pigments, due to the requirements of toxicity, carcinogenicity and pollution, there are not many practical ones in life.
(1) sauce color. A reddish-brown pigment formed by coking sucrose or glucose at high temperature. It is not a single compound, but a sugar dehydration condensate heated at 180 ~ 190℃, called caramel, which contains 100 compounds. Starch is a commonly used raw material in industry.
(2) pickling and coloring. Because of the interaction between myoglobin and hemoglobin and nitroso, meat products such as ham and sausage are bright red. In order to produce nitrite, nitrate is often added, and sodium nitrite is also used, which is called chromogenic agent. Ascorbic acid is often mixed with chromogenic agent as reducing agent. Because nitroso reacts with amino groups in meat to produce nitrosamines, which can cause cancer, pickled products have been used less in recent years. It is generally stipulated that the nitrite residue in bacon and bacon shall not exceed 70PPM.
(3) Color development of metal salts. When copper sulfate solution is sprayed on vegetables and fruits, copper ions will combine with protein of plants to form relatively stable blue or green substances. At this time, copper ions replace magnesium ions from the center of porphyrin ring to form copper chlorophyll, which has a bright solid color background. In the storage of melons and beans, the amount of copper salt should not exceed 0. 1g per kilogram, and 0. 15g in kelp ... Using dried green leaves, silkworm excrement and seaweed as raw materials, the chlorophyll contained in them is extracted with organic solvent, and copper chlorophyll can be obtained by adding copper salt solution and heating. This product is mainly used for coloring chewing gum and bubble gum, and the dosage is not more than 0.04g/kg. If treated with methanol solution of sodium hydroxide, sodium copper chlorophyllin can be obtained, which is a blue-black substance. Sodium iron chlorophyllin can be prepared by the reaction of chlorophyll solution with ferrous chloride.
Second, the smell and taste of food.
Although perfume compounds have the characteristics of low content, complex components, high reactivity and strong variability in the process of concentration or enrichment, it is difficult to study the chemistry of aroma and odor. However, after long-term exploration and research, people have a certain understanding of the chemical basis of fragrance or odor.
1. Chemical basis of fragrance or odor
From the chemical structure, the molecular weight of various perfume components is low, and the volatility and water solubility are still quite different. Alkane derivatives with 5 or less carbon atoms, such as methyl sulfide and ethyl acetate, are volatile and have good water solubility. However, aromatic derivatives with large molecular weight, such as phenylaldehyde and coumarin, are not volatile and have good oil solubility. These characteristics broaden the choice of spices. They usually have some characteristic functional groups. Take a compound containing two carbon atoms as an example: ethane, tasteless; Ethanol, wine fragrance; Acetaldehyde, pungent; Acetic acid, vinegar fragrance; Ethyl mercaptan, garlic flavor; Dimethyl ether and ether fragrance; Dimethyl sulfide, tomato or vegetable fragrance. In addition, ester compounds such as ethyl acetate are fruity, and methylthiopropionaldehyde is potato, cheese or meat.
There is an olfactory sensitive area in human nasal cavity, with an area of only 5 square centimeters, but there are about 1× 107 cells. The odor receptor on the cell is a kind of protein. When gaseous odorous substances and odorous molecules act on it, the conformation of protein molecules changes, which in turn leads to the change of surface potential, thus realizing nerve excitement adapted to stimulation. Through the transmission of excitement, the nerve center can perceive the existence of incense or smell, and sensitively feel the olfactory information provided by various volatile components in food. When a cold clogs the nose, the food is tasteless, because the chemicals emitted when chewing the food can't reach the olfactory cells because the nostril passage is blocked. Because this interaction in the process of acceptance is very specific and special, everyone feels different degrees of fragrance and smell.
Supplement to the report respondent 2009-09-22 09: 16 2. Common edible spices and their chemical constituents.
(1) natural flavor
There are many kinds of spices in China, such as bitter rose in Yongdeng County, Gansu Province. Its fragrance consists of 280 compounds, and its quality is comparable to that of the world-famous Bulgarian rose. Jasmine in Guangdong and Fujian contains more than 80 chemical components. There are more than 100 aroma components in Kweichow Moutai. There are 79 kinds of aroma components in mushrooms. Commonly used natural spices include star anise, fennel, pepper, ginger, pepper, mint, orange peel, clove, osmanthus, rose, nutmeg and cinnamon. They can be directly used in cooking, and they can also extract essential oils as raw materials for preparing spices. This kind of essential oil includes sweet orange oil, orange oil, lemon oil, spearmint oil, peppermint oil, Chili oil and osmanthus extract, all of which are non-toxic. Different chemical components give different flavors to spices. For example, mustard or mustard contains propenyl mustard oil; Grapes contain nocarone; Clove contains eugenol; Holly oil contains methyl salicylate; Sugar and fruit contain maltol; Pear contains ethyl sebacate; Peppermint contains menthone; Zanthoxylum bungeanum mainly contains pentadiene and citronellol, and its spicy ingredient is an unsaturated amide compound Zanthoxylum bungeanum. The main component of pepper is piperine; Pepper contains capsaicin; Perilla oil, garlic oil and ginger oil contain propylene sulfide; Illicium verum, fennel, fennel oil, bitter almond oil, cardamom oil and celery rapeseed oil contain anethole and fennel ketone.
(2) Artificial perfume
Mainly vanillin, with the unique aroma of vanilla beans; Benzaldehyde, also known as artificial bitter almond oil, has the special aroma of bitter almond; Citral, with strong lemon aroma, is a colorless or yellow liquid; α -amyl cinnamaldehyde is a yellow liquid, similar to jasmine fragrance; Isoamyl acetate, called banana oil; Benzyl acetate is jasmine fragrance; Ethyl propionate, pineapple aroma; Isoamyl isovalerate, apple aroma; Maltol, also known as maltitol, is a pale yellow needle-like crystal or powder with a burnt sweet taste. Although its own aroma is not strong, it has the function of relaxing and improving the aroma of other spices, and is often used as flavoring agent or fixative.
(3) Edible essence
There are two kinds of water soluble and oil soluble. The former is prepared with water or ethanol, which is mostly used for seasoning cold drink products and wine materials, and is not suitable for high-temperature flavoring; The latter is made of refined vegetable oil and glycerin, which has good heat resistance and is suitable for seasoning biscuits and cakes. Essence generally refers to the fragrance extracted from natural spices with water, ethanol or some vegetable oils with good texture, and can also be made into suitable solutions with synthetic spices as raw materials for various essences. Among them, geranone, geraniol and geranyl formate are the most important flavors.
Usually, it is more convenient to add fragrance directly to the juice extracted from a certain plant. For example, sesame oil can be extracted from holly, mint, citrus, lemon, ginger and sesame, all of which can be used as spice additives. Cinnamomum camphora oil made from camphor tree roots is the main flavor source of light wine; Many flowers, such as osmanthus fragrans and jasmine, are excellent fragrance sources for extracting spices.
Seasoning is a special technology, with many fragrance types, mainly including two types: ① floral fragrance type. Such as rose, jasmine, orchid, osmanthus, musk and so on. Imitate the fragrance of various famous flowers in nature; ② Imaginative type. Such as Xiang, Guo, Fangfang (orchid type), Dongfang, Feifei (grass type), Gulong (citrus type), Meijiajing and so on. That is, on the basis of perfuming, use appropriate reputation to strengthen psychological effect.
3. Other smells
Refers to the odor caused by other unknown reasons in life. For example:
(1) Esterification produces ester flavor.
Vegetables and melons often have fragrance, which is produced by biosynthesis. Fatty acids in fruits are produced by acyl-coa intermediates, which can react with alcohols to form esters. Methyl ketone can be produced by oxidation and deacidification of fatty acids. Both substances can give off fragrance. When cooking fish and other aquatic products, adding vinegar and wine can achieve the purpose of removing fishy smell and enhancing fragrance. Deodorization is because dimethylamine and trimethylamine with fishy smell are alkaline substances and can be neutralized with acetic acid. The perfume is ethyl acetate produced by esterification of acetic acid and ethanol.
(2) the odor produced by various decomposition.
When garlic and onion were sliced, the original protective film was destroyed. Amino acid sulfoxide, which is originally nonvolatile and tasteless, decomposes in the presence of oxygen, releasing a series of odorous compounds such as hydrogen sulfide, mercaptan and disulfide. Coffee and barbecue, especially roast beef and mutton, have a unique flavor. It is because glucose and amino acids are heated to form pyrazine, which has a nutty taste and a baking aroma. Triglyceride and protein interact when heated to produce sulfhydryl and hydroxythiophene, dihydrogen and tetrahydrofuran, which have the characteristic flavor of roast mutton and roast beef. More than 500 volatile chemicals have been found in the aroma of coffee. More than 360 compounds were identified in the aroma of roast beef, including 44 alkanes and alkenes, 30 alcohols, 32 ketones, 22 acids, 23 furans, 34 pyrazines, 22 thiophenes, 65,438+00 pyridine and 65,438+06 lactone.
Family life will also have various smells, mainly from feces and garbage. For example, the odor emitted by the toilet is mainly the irritating gases ammonia and indole compounds with stench in feces. The smell of rotten cabbage and bad people is mainly due to the emission of hydrogen sulfide gas. There are also rancidity of oil, rancidity of fish and rancidity of human sweat, which are mainly caused by dimethylamine, trimethylamine and various lower aliphatic amines, phenols, aldehydes or hydrogen sulfide and carbon disulfide.
Third, the taste of food.
Taste is the sour, sweet, bitter, spicy and salty taste tasted by the tongue, and it is the taste produced by the soluble substances dissolved in saliva acting on the taste buds of the taste nerves on the surface of the tongue. Proper taste can make digestive juice secrete vigorously, increase appetite and help digestion.
1. acid
Sour taste comes from dissolved hydrogen ions (H+). Acids are divided into inorganic acids and organic acids, strong acids and weak acids. Common hydrochloric acid, sulfuric acid and nitric acid are inorganic strong acids, while acetic acid, lactic acid and citric acid are organic weak acids. All strong acids are ionized (or dissociated) in aqueous solution, resulting in high H+ concentration and high acidity. Weak acid can only be partially ionized in aqueous solution, which leads to the decrease of H+ concentration and acidity. In order to express the acidity of different acids, people introduced the concept of "acid taste" to express the relative acidity of various acids with the same concentration: hydrochloric acid 100, formic acid 84, citric acid 78, malic acid 72, lactic acid 65, acetic acid (acetic acid) 45 and butyric acid 32.