1. Look at transparency.
After the edible oil was left standing in a transparent bottle for 24 hours, the transparent one was the top grade, followed by the turbid one with suspended matter, and the quality of the precipitate was poor. If barrel bottom oil is randomly selected, no more than 5% of sediment is high-quality oil.
Look at the color
Observe the oil in a colorless and transparent container in a bright place and keep the original color as good oil.
Smell
Rub your palm with a little oil and smell it. If there is a pungent smell, it means that its quality is poor.
Check moisture
Insert a clean and dry glass tube into the oil. Block the top of your mouth with your thumb and slowly pull up. If the oil is milky white, it means there is water in the oil. The thicker the milky white, the more water.
Step 5 taste
If you directly taste a small amount of oil, if you feel sour, bitter, spicy and burnt, it means that its quality is poor.
heat
Heat the pot to about 150℃, cool it and pour out the oil to see if there is any precipitation. Precipitation indicates that it contains impurities.
Second, the identification of various edible vegetable oils
1. peanut oil
It is an oil extracted from peanut kernel, generally light yellow or orange yellow, and its color is clear and transparent. Peanut oil has a white foam head and big bubbles, and has the inherent smell and taste of peanut oil.
2. Rapeseed oil
It is an oil extracted from rapeseed and used to be called vegetable oil. Generally, raw rapeseed oil is golden yellow, the oil hair is slightly green, and the flowers are colored when the sun is full, which has the inherent smell of rapeseed oil. Taste the fragrance with spicy food.
3. Soybean oil
It is an oil extracted from soybean, also called soybean oil. Generally yellow or brown, with white fur and complete flower bubbles. Beans smell strong and taste astringent.
4. Cottonseed oil
It is refined oil extracted from cottonseed, generally orange or brown, with yellow foam hairs and small flower bubbles, and tasteless.
5. sunflower seed oil
This is oil extracted from sunflower seeds. The oil is clear, light yellow or yellow, fragrant and pure.
Third, how to identify the quality of sesame oil
1. View colors
Authentic color is reddish or reddish with yellow. Machine pressed sesame oil is lighter than ground sesame oil. The oil flower mixed with rapeseed oil is pale yellow, the oil flower mixed with cottonseed oil is black and the oil flower mixed with peanut oil is white.
Smell incense
In the process of making pure sesame oil, the rich and pure sesame fragrance is retained, and the fragrance is more lasting. The real fragrance of kitten sesame oil is mellow, rich and unique. If it is mixed with peanut oil, soybean oil or rapeseed oil, the fragrance will become worse and it will smell like peanuts and beans.
Observe the shape
Drop a drop of fragrant oil in a bowl filled with clear water. Pure sesame oil turns into fine flowers, which quickly disperse and condense into several small oil beads, while adulterated sesame oil flowers are big and thick, which are not easy to disperse.
freeze
Put the sesame oil in the refrigerator or freezer and freeze it at-10℃. Pure sesame oil is still liquid at this temperature, while adulterated sesame oil begins to coagulate.
heat
The color of pure sesame oil is slightly darker after heating, and no precipitation is produced. If mixed with lard, it will turn white, if mixed with rapeseed oil, it will turn blue, if mixed with cottonseed oil, it will pollute the pot, and if mixed with rice soup or winter melon soup, it will precipitate after half an hour.
watering
If 15% water is mixed into sesame oil, it will be opaque liquid under light (fresh sesame oil is also liquid, but it looks sticky); If 35% water is mixed into sesame oil, the oil is layered and has no strong fragrance, so it is fake sesame oil.
Fourth, how to identify shrimp oil
1. color
Put a small amount into a transparent container (bottle) and observe whether it is transparent and whether there are suspended particles in the light. Good shrimp oil should be orange red or orange yellow, without black.
2. Aroma
Shake the bottle gently and smell it. Good shrimp oil has unique meat flavor and fresh flavor, and has no rancid smell.
taste
Take a small sample and put it in your mouth. Good shrimp oil tastes delicious, has a delicate aftertaste, has no bitterness and peculiar smell, and is not salty.
Observe foam
Shake the bottle evenly by hand to make it foam. If the foam disappears soon, it means that the fermentation is complete and it can be stored for a long time, otherwise it will not last long.
Five, identify ginger knowledge
Ginger commonly used in cooking includes new ginger, yellow ginger, old ginger and water ginger.
The new ginger skin is thin and tender, and the taste is weak;
The spicy taste of turmeric changed from light to strong, and the meat quality changed from soft to hard, which is the top grade of ginger.
Ginger, commonly known as ginger mother, is a kind of ginger with thick skin and strong meat and spicy taste;
Pour ginger with ginger buds, which can be used as a side dish or dipped in sauce. It's delicious.
Six, the main points of buying cinnamon
1. Wen Xiang
Dig the belly of cinnamon with your nails until there is a slight oil oozing out and the smell is pure; Breaking the horizontal plane or biting cinnamon with your teeth will make you feel fragrant, cool and heavy, and slightly sweet is the top grade.
2. Distinguish sound from shape
The dry cortex of Cinnamomum cassia is hard and fragile, and it is easy to break when folded by hand, with a loud sound and a flat section. Wet impurities are silent and tough when broken, and the section is serrated.
Look at the color
Cinnamon has a light brown surface, a brown interior, fine lines on the surface, and good quality with luster on both sides or inside. The skin is dark brown with moldy green spots or grayish white spots.
Check length
Generally, the length of the skin is above 35 cm, the thickness is even, the mass is about 3 ~ 5 mm, and the length below 10 cm is a defect.
Seven, star anise purchase instructions
1. shape
A real octagon has eight angles, and a fake octagon generally has more than ten angles. The real star anise is fat and big, and the fake star anise is thin and small. The true star anise fruit handle is straight, while the false fruit handle is curved. The real star anise is full and bright, while the fake star anise is thin and dark.
Step 2 taste
The real star anise is sweet to chew, while the fake star anise has a pungent bitter taste and camphor smell.
Smell
The real star anise has pure fragrance, while the fake star anise has pine leaf flavor.
Illicium verum is the seed of weeds, which is very toxic. Its shape and color are similar to that of Illicium verum, which is easily mistaken for Illicium verum, causing food poisoning. So be very careful when buying star anise.
Eight, the identification of true and false Chili noodles
Authentic pepper noodles are brown powder with a pungent and special aroma. Sneeze with pungent smell, taste with the tip of your tongue, and you will soon be numb.
Adulterated pepper noodles are often yellowish powder in appearance, or moldy and caked. The taste of pepper is very light, and the tip of the tongue is slightly numb or not, which is very bitter to eat.
Nine, the purchase of Chili powder
Normal Chili powder should be red or red-yellow, oily and evenly powdered. It has the inherent spicy taste of pepper, smells pungent and sneezes. Common adulterants in Chili powder are bran, yellow cereal powder, tomato dry powder, sawdust, dried vegetable leaf powder, red brick powder and so on.
The adulterated Chili powder is brick red, with a large number of sawdust or green leaves visible to the naked eye, and can smell a little or no spicy taste.
If the Chili powder is light in color and yellow, it feels sticky when put in the mouth, and it can be pasty when put in clear water, it is mixed with corn flour or other yellow particles.
If the Chili powder is heavier than the normal goods, the fragments are uneven, and the teeth are felt with the tongue, it is mixed with red brick powder. If there is too much yellow powder in Chili powder, it smells like beans and tastes slightly sweet, it is mixed with bean powder.
Ten, monosodium glutamate purchase common sense
1. Identify common sense
There are 99%, 90%, 80% and 70% marks on the packaging of monosodium glutamate, which refers to the content of sodium glutamate in monosodium glutamate and is also the main factor determining the quality of monosodium glutamate.
For example, "80%" means that monosodium glutamate contains 80% sodium glutamate, and the remaining 20% is refined reconstituted salt.
Adding salt to monosodium glutamate is not only the stuffing, but also the fresh-keeping effect of salt on monosodium glutamate.
Sodium glutamate monosodium glutamate is high in content and delicious, so it can be used less. On the contrary, the content of monosodium glutamate in monosodium glutamate is low and the flavor is small, so it should be increased appropriately when used.
2. Quality performance
High-quality monosodium glutamate particles have the same shape, white and shiny color, and the particles are loose. Diluted to the ratio of 1: 100, the taste still feels delicious.
The inferior monosodium glutamate particles vary in shape and size, and the color is black and yellow, and even the particles become a lump. When diluted to the ratio of 1: 100, you can only feel bitter, salty or sweet, but there is no umami flavor.
3. Identification of strengths and weaknesses
True monosodium glutamate is a white crystal with uniform powder, while fake monosodium glutamate has different colors and uneven powder.
True monosodium glutamate feels soft and has no graininess, while fake monosodium glutamate feels rough and has obvious graininess. If it contains raw powder and baking soda, it will feel too greasy.
The real monosodium glutamate has a strong taste. If the salty taste is greater than the umami taste, it means that salt is mixed; If there is bitterness, it means that magnesium chloride and magnesium sulfate are mixed together; If it is sweet, it means adding sugar; It is difficult to dissolve, and it feels cold, slippery and sticky, indicating that cassava powder or gypsum powder is mixed.
XI。 How to buy soy sauce
1. View colors
Good quality soy sauce. The color is ruddy, reddish brown or brown, and it is not turbid and has no sediment when it is clarified.
Smell incense
Good quality soy sauce has a slight sauce flavor and ester flavor, and has no other peculiar smell. If soy sauce smells musty or burnt. It means that soy sauce is moldy and inedible.
taste
Good quality soy sauce is delicious and palatable.
Observation state
For example, when filling soy sauce, turn the bottle upside down to see if there is any sediment left at the bottom of the bottle, and then shake it vertically to see if there is any debris left on the bottle wall, whether the liquid in the bottle is turbid and whether there is any suspended matter. High-quality soy sauce should be clear and transparent, without sediment, sediment and mold floating film.
5. Standard
When buying soy sauce, try to choose products marked with the words brewed soy sauce, and pay special attention to the amino acid nitrogen index on the label of brewed soy sauce. The higher the index, the better the quality of soy sauce.
Twelve, the misunderstanding of soy sauce purchase
1. The darker the soy sauce, the better.
The color of soy sauce is determined by caramel, which is a compound produced by the interaction between amino acids and sugar in soy sauce. The darker the color of soy sauce, the more amino acids and sugars are consumed. When the color is dark enough, there are few nutrients left in soy sauce.
The fresher the soy sauce, the better.
Adding excessive hydrolyzed protein, glutamic acid, nucleotide, etc. Adding soy sauce in the blending process can enhance the umami flavor, but it is harmful to human health.
The higher the price, the better.
High-quality soy sauce is clear, free from precipitation and floating film, reddish brown in color, thick, with sauce flavor and ester flavor, which is not absolutely related to the price.
4. Sauce and sauce are both soy sauce.
Sauce, sauce and soy sauce are two different things. Every 100 ml of soy sauce contains at least 0.4 g of amino acid nitrogen, while soy sauce and soy sauce basically do not.
All soy sauce can be used for stir-frying or cold salad.
The use of soy sauce can be divided into cooking and table service. The fermentation process and hygienic index of the two are different and cannot be substituted for each other.