Avaliação do metabolismo antioxidante durante o desenvolvimento de frutos de clones de aceroleira e sapotizeiro

Abstract

Fruit ripening is a complex developmental process involving changes in biochemical, physiological and sensorial characteristics as well as in the oxidative metabolism which result in their quality attributes and antioxidant properties This research described the major changes in the antioxidant systems during development of two tropical fruit species Acerola (Malpighia emarginata D.C) and sapodilla (Manilkara zapota L.) fruits were analyzed at different maturity stages for quality parameters post-harvest antioxidant compounds total antioxidant activity (TAA) antioxidant enzymes activity and cell membrane integrity Ripening process promoted improvements in post-harvest quality of tropical fruits studied In acerola the total vitamin C and total soluble phenols (TSP) content reduced during development which resulted in decline of total antioxidant activity (TAA) In spite of the decline in TSP the yellow flavonoid and total anthocyanins content showed an evident increase at ripening which may be associated to fruit coloring and antioxidant nutrition properties While in sapodilla antioxidant compounds contents reduced significantly during the fruit development which contributed to decreased of TAA that resulting mainly from the decline of phenolics contents such as TSP and yellow flavonoids because sapodilla is not a good vitamin C source The activities of oxygen-scavenging enzymes superoxide dismutase (SOD) catalase (CAT) and ascorbate peroxidise (APX) decreased with tropical fruits ripening which contributed to an increased oxidative stress as evidenced by lipid peroxidation therefore necessary to make easy many changes related to aging The development of tropical fruits studied was accompanied by progressive increase in oxidative and peroxidative stress which can contributed to the fruit postharvest quality and nutritional antioxidant potential.