Biotic and Abiotic Factors Affecting the Content of the Chosen Antioxidant Compounds in Vegetables

Vegetables are a rich source of biologically active substances, which support the body's defense mechanisms. A large group of these substances are compounds with antioxidant properties. Apart from vitamins (A, C and E), tocopherols, carotenoids, glutathiones and thiocyanates, polyphenols are also classified as the compounds of antioxidant properties being found in plants. They include: phenolic acids, flavonoids and hydroxycinnamic acid and among them a large group of anthocyanins. These compounds inhibit DNA damage in cancer cells, induce the production of insulin in the pancreas and protect the human brain from aging. They have also high antioxidant activity, which determines the defense mechanisms of plants under stress, such as temperature varia-tions, UV radiation, attacks by pests and mechanical damage. Their content may vary among individual plants of the same species, which is associated with a number of internal and external conditions, such as genetic factors, environmental and agronomic. The contents of anthocyanins determines plant species, botanical variety and breeding and biological processes associated with ontogenesis. Also climatic and soil factors, the factors influencing the content of antioxidants and agronomic factors such as method, place and date of planting, fertilizing, mulching, salinity may contribute to the formation of stress conditions during plant growth and increase the content of antioxidants in plants. This review focused on the content, composition, and antioxidant capacity of vegetables.