As winter arrives, many incorporate Chinese yam into their meals. Traditional Chinese medicine has long valued it as a superior medicinal herb. Sweet and cooling in nature, it enters the lung, spleen, and kidney meridians. The Compendium of Materia Medica describes its ability to replenish deficiencies and restore vitality.
Modern pharmacological research indicates that yam contains saponins, glycoproteins, tannins, diosgenin, diosmin, choline, starch, and minerals like calcium, phosphorus, and iron. These components induce interferon production and provide a foundation for anti-aging properties. Thus, yam genuinely nourishes deficiencies, repairs damage, and promotes longevity.
Many people experience intense itching on their hands when peeling Chinese yam, with severe cases presenting redness, swelling, and stinging pain. Why does Chinese yam cause this itching? Let's explore below.
Why Does Yam Cause Itchy Hands?
Note: This sensation is medically classified as contact dermatitis. Since not everyone experiences it upon contact, it may also indicate an allergic reaction. Current research suggests saponins in the skin or alkaloids in the mucilage trigger this condition—skin exposure to either component causes itching.
While yam boasts a delicate texture and sweet flavor, its skin can easily trigger skin allergies. It's best to peel it thoroughly and avoid touching other areas immediately afterward. Wash your hands multiple times promptly, or you'll find yourself scratching wherever it itches.
In fact, after washing the yam skin clean, it's advisable to wear gloves or slip a plastic bag over your hand before peeling.Alternatively, prepare a pot of boiling water. After washing the yam, immerse it briefly in the boiling water. This partially cooks the skin, destroying the allergens and preventing future reactions. After removing the yam from the pot, simply run a knife gently from top to bottom to easily peel off the skin. Be careful not to overcook it, and it's best to boil the yam whole rather than cut.
Sliced yam turns yellow when exposed to oxygen and blackens when cooked in iron pots. To prevent discoloration, steam the unpeeled yam for one minute or microwave it for one minute to deactivate the polyphenol oxidase.
What to do if yam causes itchy hands?
Yam is a delicious and nutritious food, but what if its juice irritates your hands during preparation?
1. The simplest solution: Wear kitchen gloves or slip on a plastic bag to avoid direct contact.
2. Pour a small spoonful of cooking oil into your palm. Spread it evenly over your hands like hand cream. This protective layer will prevent itching when handling yam.
3. Post-exposure remedy. If your hands are already itchy after handling yam, wash them with clean water and dry thoroughly. Turn on the stove to the lowest heat setting, place your hands above the flame in a safe area, and gently warm them for a moment to effectively relieve the itch. Alternatively, fill a basin with water, add a small amount of vinegar, mix well, and wash your hands with this solution to stop the itching.Alternatively, wash hands with soap, then rub white liquor onto hands and allow it to evaporate naturally. After evaporation, wash hands again with soap to relieve itching. Finally, if skin accidentally becomes itchy, applying ginger can also stop the itch.
How to Select Yam?
First, assess weight: heavier yams of the same size are better. Second, examine root hairs: within the same variety, yams with more root hairs are superior.More root hairs indicate a starchier texture, higher polysaccharide content, and greater nutritional value. Finally, examine the cross-section: the flesh should be snow-white, signifying freshness. Avoid any with a rusty yellow hue.
Important note: Never purchase yams with abnormal surface spots, as this may indicate disease infection.Additionally, the cut surface should exhibit a sticky mucilage, and the skin must be undamaged. Yam is sensitive to both freezing and excessive heat. When purchasing in winter, hold it in your hand for about 10 minutes. If it sweats, it has been frozen. When broken open, frozen yam will have mucilage that turns watery on the cross-section, a hard core, and reddish flesh—indicating poor quality.