Allium Cepa is type of onion (vegetable), its botanical name is Liliaceae. It is cultivated in Japan and it is known as bunching onion. These onions are dried and served as food in the form of pickles and chutneys. The leaves are flattened, fan shaped, and yellowish to bluish in colour. They have a pungent smell and certain chemical substances in it cause irritation to eyes. It is known as charaka samhita in Ayurvedic tradition. Allium Cepa contains 89% of water, 9% carbohydrates, 1% protein, and also flavonoid contents (flavonoid- it is a metabolites which provide antioxidants effect)