The conjugated system in which the p electrons are delocalised over the entire length of the polyene
chain is responsible for the molecular shape, chemical and physical reactivity and the antioxidant
properties of carotenoids. It is sensitive to heat, light and oxygen. Enzymatic and non-enzymatic
oxidation is the major cause of carotenoid destruction during processing and storage of food. Bioavailability
of carotenoids from different food requires disruption of the food matrices. Thermal
treatment and freezing increases the extractability of b-carotene from the food matrices. Ripening is
accompanied by increased carotenoid biosynthesis.