Onions, also known as bulb onions, common onions, shallots, or salad onions, are extremely nutritious and a unique 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.
According to their 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 long cooking, they develop a golden color and rich sweetness, making them more suitable for eating fresh, baking, or stewing, but with a lower yield. Purple onions have slightly reddish flesh, a strong pungent flavor, are suitable for stir-frying, braising, or raw salads, but have poor storability. Yellow onions are mostly for export, with slightly yellow, tender, and delicate flesh, a sweet taste, and a medium pungency. They are suitable for eating raw or with dipping sauce, are well-storable, and are often used as dehydrated vegetables.
In terms of nutritional value, purple onions are slightly more nutritious. This is mainly because the stronger pungent taste of purple onions means they contain more allicin. In addition, 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 formula. Wash the onions, peel them, and dice them. If purple onions are used, do not remove the purple skin, as it will enhance the efficacy when soaked in wine.