Phytochemicals present in vegetables are very diverse, such as ascorbic acid carotenoids and phenolic compounds. Phytochemicals provide protection against bacterial viral and fungal infection; ward off insects and prevent tissue damage due to oxidation.
Some act as plant hormones or participate in the regulation of gene function, while others provide plants with flavor and color.
Naturally occurring compounds such as phytochemicals, which possess anti-carcinogenic and other beneficial properties, are referred to as chemo-preventers.
Although thousands of biological active substances in plants have been identified, knowledge of their effects on human health is currently known for only a small number of them.
Phytochemicals are categorized into different groups according to their chemical structures (e.g. polyphenols, carotenoids, organo-sulfur compounds, alkaloids and N-containing compounds).
The climate, season, temperature and rainfall, as well as cultural practices, processing techniques and storage conditions are all important factors affecting phytochemical content in vegetables and related food products.
Example of phytochemicals in vegetables:
*Allicin – in chives, garlic, leeks onions
*Curcumin – in turmeric
*Indoles – in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower
*Isothiocyanates - in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower
*Saponins – in alfalfa sprouts, green vegetables, tomatoes
Phytochemicals in vegetables