The onion, also known as a bulb onion, common onion, or shallot, is an extremely nutritious vegetable that combines nutritional, medicinal, and health benefits. Similar to garlic, onions contain allicin and selenium sulfide, which can inhibit the synthesis of carcinogens and promote phagocytic cells to destroy cancer cells, thus having anti-cancer effects.
Based on skin color, onions can be divided into three types: white, yellow, and purple. White onions have tender flesh, high water content, and high sweetness. After prolonged cooking, they develop a golden color and rich sweetness, making them more suitable for eating fresh, baking, or stewing, though they have a lower yield. Purple onions have slightly reddish flesh and a strong pungent taste, making them suitable for stir-frying, braising, or raw salads, but they have poor storage properties. Yellow onions are mostly for export; they have pale yellow, tender, and delicate flesh with a sweet taste and moderate pungency. They are suitable for eating raw or with a dip, have good storage properties, and are often used as dehydrated vegetables.
In terms of nutritional value, purple onions are slightly more nutritious. This is mainly because their stronger pungent taste means they contain more allicin. Additionally, the purple skin of purple onions contains more quercetin, which is also a very beneficial health component for the human body. Therefore, the therapeutic effect of purple onions is much better than that of white onions. Onion red wine is a very magical health-preserving formula. Wash the onions, peel them, and chop them into small pieces. If using purple onions, do not remove the purple skin, as it provides better health benefits when soaked in wine.