1, when choosing a kidney, you should look at its color: fresh kidney is soft, shiny, elastic and reddish; The stale kidney is blue, turns white after soaking, has soft texture, inflates inelastic and gives off peculiar smell.

2. See if there are blood spots on its surface. If there is, it is not normal.

3. See if it is thicker than ordinary pork loin. If it is thick and big, carefully observe whether it belongs to the red and swollen waist of the pig. The inspection method is: cut the pork tenderloin with a knife to see if the medulla (between the red tissue and the white tendon) and cortex are blurred. If it is, it is not normal. Don't buy it.

Extended data:

Pig kidney contains protein, fat, carbohydrates, calcium, phosphorus, iron and vitamins. It is nutritious and has the effects of tonifying kidney and waist and regulating qi. Pig kidney tastes sweet and salty, and has a flat nature. It enters the kidney meridian and has the function of tonifying kidney, strengthening waist and benefiting qi.

Ordinary people can eat it, and it is also a kind of food in daily life. It is suitable for people with kidney deficiency such as backache, nocturnal emission and night sweat, and also suitable for the elderly with kidney deficiency, deafness and tinnitus. It should be noted that people with hyperlipidemia and high cholesterol should not eat it. Animals' kidneys are detoxification organs, and there will be certain toxins in them. Although some toxins can be removed after cleaning and cooking, they will still remain, so it is best not to eat them every day, but once or twice a month.

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People's Network-Waist and knee are sour and soft to eat pork loin