[Biologically-active phytochemicals in vegetable food].

Phytochemicals constitute a heterogeneous group of substances and evidence for their role in the protective effect on human health, when their dietary intake is significant, is emerging. These compounds have biological properties as antioxidant activity, modulation of detoxification enzymes, stimulation of the immune system, decrease of platelet aggregation and modulation of hormone metabolism. Glucosinolates and widely group of polyphenols, including the main category of flavonoids, are examined. Since their weak estrogenic activity is of interest at present, isoflavones are discussed at length. Numerous factors affect the phytochemical content and availability in plants; these factors include environmental conditions and industrial or domestic processing. The bioavailability of phytochemicals can be influenced by intrinsic factors in food and/or in human, in general the substances are little adsorbed, largely metabolized and rapidly eliminated. For this reason it is advisable that their consumption is constant in the time to maintain high concentrations of metabolites in the blood.