EVALUATION OF STARCH AS AN EDIBLE COATING ON PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN GUANABANA (Anonna muricata L.) FRUITS

Abstract

Soursop fruit (Annona muricata L.) is climacteric and highly perishable, it has a high respiration rate that causes an accelerated softening of the fruits, which is manifested in a short shelf life and causes several problems in its postharvest handling and, consequently, their storage and commercialization are limited. Edible coatings are an alternative that can help to increase shelf life, in addition to preserving the physicochemical, physiological and nutraceutical characteristics (bioactive compounds) associated with the quality of the fruits. The objective of this study was to evaluate the changes in antioxidant activity by the DPPH, ABTS and FRAP methods, as well as the content of phenols, flavonoids and vitamin C during the maturation of soursop fruits without and with starch-based coating, stored at 22 and 15 ± 2 °C with relative humidity of 90 %. The coated fruits stored at 15 ± 2 ºC presented the highest antioxidant activity (mg EAA/100 g.f.w.), 285 (DPPH) and 15.92 (FRAP), respectively; while in the uncoated fruits at the same storage temperature, their antioxidant activity was lower, 46.5 and 52.4 (ABTS); likewise, under these conditions the concentration of phenolic compounds was 90.6 and 93.98 mg EAG/100 g.f.w. Regarding the concentration of vitamin C and flavonoids, it was higher in the coated fruits stored at 15 ± 2