Status and trends of nutraceuticals from onion and onion by-products: A critical review

The pivotal roles of vegetables are predominantly important for health due to availability of minerals, vitamins, phytochemicals and antioxidants. These foods and food products those are prepared from such kind of material having natural origin have great importance due to their versatile nature. Onion importance is greatly increasing and now it has become second most medicinal and horticultural crop after tomatoes. It has multiple functional compounds including organosulphur, anthocyanins, flavonoids, quercetin, kaempferol and polyphenols. Antibacterial, anti-inflammatory and antioxidant properties are the various diverse functions of onions, which have sound effects on human health. Fructo-oligosaccharides are present in abundant quantity in it due to which the growth of potentially harmful bacteria in the colon is retarded by the oligomers thus reducing the risk of emerging tumors in the colon and also initiates the growth of healthy bifidobacterium. In the nutshell, the onion and onion by-products have a lot of bioactive compounds against certain metabolic disorders.