Why is the yam red?

Yam has another more poetic name called Huaishan, but there is a layer of mucus under the skin of yam, so everyone must be careful to protect their hands when handling yam, otherwise the skin of their hands will easily become itchy after being stained with this mucus. As a potato crop, yam contains a lot of starch. However, some people find that yam will turn red after being left for too long. What's going on?

Why is the inside of the yam red?

This is normal. Some substances in the yam will be oxidized when exposed to air and will turn red. However, it can still be eaten after turning red and is harmless. If you think it doesn't look good, you can add a little salt to the peeled and washed yam and mix it. This way the peeled yam will not change color.

Can I still eat yam if it turns purple?

It is normal for the yam to turn purple and be edible. The skin of some yams has a layer of purple. This is related to the soil and variety in which it is planted. The iron stick yam is the most common. After peeling, the yam flesh inside still has a layer of light purple. This kind of purple yam can be eaten with confidence. Yams contain phenols and classified oxidases, while the air contains oxygen. After the yam is peeled, a reaction will occur. The generated quinones will appear brown or black. Slight oxidation may also appear light purple, which can also be eaten. If it turns purple abnormally, it cannot be eaten. Yams can be stored for a long time like sweet potatoes and potatoes, but you need to pay attention to the loss of water in the yam. If it is stored for too long, the water in the yam will be lost in large quantities, or part of it will begin to rot, and the heart of the yam will turn purple. This kind of yam contains certain toxins and is not suitable for consumption.

Why does the yam turn purple?

It is normal for yam to turn purple-red after peeling, because iron stick yam contains rich elements.

1. Purple is the sign of iron stick yam. Generally, there is no purple on the yam. It is rust. There is no problem. You can see it without peeling it. After peeling, there is a light purple layer. It is normal.

2. The purple color is usually on the inside, and you can see it after peeling off the skin. This purple color is usually only seen in winter and is rarely seen when the weather gets hot.

3. The purple and browning produced after peeling are mainly caused by three conditions: polyphenols, polyphenol oxidase and oxygen. After the yam is peeled and exposed to the air, the polyphenols in it react with oxygen to produce o-quinone, which is further oxidized and polymerized to form brown pigment and melanin.

The efficacy and function of yam

1. Strengthening the spleen and stomach. Yam is a food and medicine that nourishes the spleen and stomach. It contains amylase, polyphenol oxidase and other substances, which are beneficial to the digestion and absorption function of the spleen and stomach. It can be eaten regardless of spleen yang deficiency or stomach yin deficiency. It is often used clinically to treat spleen and stomach weakness, poor appetite, fatigue, diarrhea and other symptoms.

2. Nourishes the kidney and improves the essence. Yam contains a variety of nutrients, which can strengthen the body, nourish the kidney and improve the essence. It can be taken for symptoms such as kidney deficiency, spermatorrhea, excessive leucorrhea in women, and frequent urination.

3. Yam contains saponins and mucus, which have lubricating and moisturizing effects. Therefore, it can benefit the lungs, nourish the lung yin, and treat lung deficiency, phlegm, cough and long-term cough.

4. Lowering blood sugar: Yam contains mucus protein, which has the effect of lowering blood sugar. It can be used to treat diabetes and is a good food therapy for diabetics.

5. Prolong life: Yam contains a large amount of mucus protein, vitamins and trace elements, which can effectively prevent the precipitation of blood lipids in the blood vessel walls, prevent cardiovascular diseases, and achieve the effects of improving the mind, calming the nerves and prolonging life.

6. Anti-hepatic coma: Recent studies have found that yam has a sedative effect and can be used to prevent hepatic coma.