UV-B radiation on lemons enhances antifungal activity of flavedo extracts against Penicillium digitatum

RUIZ, V.; CERIONI, L.; ZAMPINI, I.C.; CUELLO, S.; ISLA, M.I.; HILAL, M.; RAPISARDA, V.

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017

0023-6438

UV-B radiation (UVBR) treatment, previously standardized in our laboratory, contributes to preventgreen mold caused by Penicillium digitatum on postharvest lemons. Here, antifungal activity of flavedoextracts from irradiated and non-irradiated lemons was assayed against P. digitatum; also, compoundsthat could be responsible for this action were searched. The flavedo extracts from UV-B exposed lemons(UVBLE) exhibited a higher antimicrobial activity than extracts from control lemons (CLE). Conidiatreated with UVBLE showed a time dependent inhibition of germination and oxygen consumption, amarkedly increase in ROS and TBARS production and in membrane permeability. By chemical analysis oflemon extracts, two fractions (A and B) that responded to the irradiation were detected, showing adecrease in Fraction A and an increase in Fraction B. Fraction B showed higher antioxidant and antifungalactivities in comparison to Fraction A. Both fractions were complex samples enriched in flavonoids. Thespecific composition of each fraction could explain the difference in the biological activities, and also thehigher efficiency of UVBLE to inhibit in vitro the pathogen compared to CLE. Based on our results, UV-Bradiation treatment can intensify natural defenses of flavedo lemon by eliciting phenolic compoundssynthesis, among other processes.