How to choose the quality of yam

In fact, there are good and bad yams, but many people will buy bad ones if they don't pick them. In fact, there is skill in choosing yam. Here are four ways to teach you how to choose Chinese yam.

How to choose yam?

1, from the appearance, yam with smooth and crisp skin is suitable for frying; If it is a stew or a dessert dish, it is recommended to choose noodle yam, which will be very sweet and full. Noodles and yam are characterized by many pockmarks, many whiskers and smoothness.

2. Look at the appearance. Slightly flat, the head is a little bent, and the color is brown; Or the stem is straight and the texture is solid; Or the shape of a small hand, are all good yam. If there are bumps, the taste may be slightly harder.

3. Then hold it in your hand. Hold yam for a period of time, the length of time can depend on the weather at that time, the warmth can be shorter, on the contrary, the holding time can be longer. After holding, the fresh yam skin has a warm feeling; Stale yam will "sweat" and tiny water drops will ooze from the epidermis, which is frozen yam. Once yam is frozen, the content of polysaccharide and free amino acid in mucus will be destroyed, the nutritional value will be reduced and the taste will be poor.

4, you can open a little skin when buying, or look at the cut surface of yam, the meat is white, and the sticky juice is fresh yam; After the frozen yam is cut, the flesh is as red as rust and the heart is as hard as water.

How can yam be peeled and not black?

Phenolic substances in yam are oxidized by oxygen in the air, and can also produce colored quinones without direct contact with the air, such as soaking in water. Salt water can be used. You can also put some white vinegar in a bowl of clear water, and the cut yam will not turn black in vinegar water.

If you don't want yam to be oxidized, it is recommended to peel it and soak it in water. If soaked in hot water, it can not only prevent oxidation and blackening, but also neutralize the alkaloids in yam that tickle people's hands and reduce the allergic reaction when grasping with hands.

Cooking yam should also pay attention to some skills, because new yam is easy to oxidize with oxygen in the air, and it will also change color after contact with metals such as iron. Therefore, it is best to cut yam after some treatment. You can draw lines on the skin with a bamboo knife or plastic blade first, and then peel it into sections by hand. You can also soak the cut yam in rice wine first, then dry it with a hair dryer to promote the healing of the incision, then wrap it in a napkin, wrap it around with several layers of newspapers and put it in a cool corner for later use.

Small knowledge of yam

As a Chinese herbal medicine with the same origin of medicine and food, Dioscorea opposita has different origin characteristics due to the influence of regional climate characteristics, geological characteristics, growth habits and other factors. Yam is mainly produced in Aibo, Wuzhi, wen county and other places in Henan, and also cultivated in Shaanxi, Shandong, Hebei, Zhejiang, Hunan, Sichuan, Yunnan, Guizhou and Guangxi. Guangxi, Hebei, Henan and other major producing areas constitute the main planting areas of yam.

Tips for preserving peeled yam

1. The peeled yam is slippery. It will be easier to handle things like vinegar or salt on your hands.

2. Do not use metal props (stainless steel can also be used) to cut yam, but use wooden or expected knives. If you use a kitchen knife to cut yam, yam may change color when it touches the metal surface of the knife, including the iron pan when cooking. This phenomenon is very common in life, such as apples, media, lotus roots and so on. After cutting, the pulp will gradually darken when exposed to air for a long time.

There are many whiskers on peeled yam. These whiskers will slow down the peeling speed when peeling. Maybe the yam turned black before it was completely peeled. It is suggested to light the yam quickly and burn the whiskers on it first, so that peeling will be faster and the time of contact with air will be reduced.

4. In order to avoid the discoloration of yam after contacting the iron pot, first put the yam with skin in a steamer or microwave oven for one minute, so that the polyphenol oxidase can be deactivated, so that it will not turn black.

5. Yam turns black after being cut because it is oxidized, but it will not affect the consumption of yam, and there will be no problem after eating it, so you can eat it with confidence. It just doesn't taste good.