Most onion cultivars are about 89% water, 4% sugar, 1% protein, 2% fibre, and 0.1% fat. Onions contain low amounts of essential nutrients (right table), are low in fats, and have an energy value of 166 kJ (40 kcal) per 100 g (3.5 oz). They contribute their flavor to savory dishes without raising caloric content appreciably. Onions contain phytochemical compounds such as phenolics that are under basic research to determine their possible properties in humans.
Onions are high in sulphur, vitamin B6 and B9. It has high quantities of water and naturally low in fat. It is high in phytochemical compounds.
It is a versatile vegetable that can be used raw, sauteed, caramelized, roasted, deep fried, pureed or boiled as required. It lends itself very
well to almost any cuisine.
It can be consumed with salads, curries or chutnies. Store in a cool dry place, need not refridgerate.
Freezing onions, soaking them under water and keeping the root intact before chopping are some methods to reduce tears while chopping them.