Overcoming lemon postharvest molds caused by Penicillium spp. multiresistant isolates by the application of potassium sorbate in aqueous and wax treatments

OLMEDO, GABRIELA M.; DEBES, MARIO A.; SEPÚLVEDA, MILENA; RAMALLO, JACQUELINE; RAPISARDA, VIVIANA A; CERIONI, LUCIANA; VOLENTINI, SABRINA I.

JOURNAL OF FOOD SCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2023

0022-1147

Abstract: Penicillium digitatum and Penicillium italicum are the main causalagents of postharvest diseases in lemon. Over the last decades, the appearance ofisolates resistant to the main commercial fungicides has been considered one ofthe most serious problems for the citrus industry. In this work, potassium sorbate(KS) was evaluated as an alternative to chemical fungicides to control postharvest diseases caused by Penicillium isolates resistant to imazalil, thiabendazol,and pyrimethanil. In vitro assays showed that 1% KS inhibited conidia germination and mycelial growth of sensitive and resistant P. digitatum and P. italicumisolates, being this effect stronger at pH 5 than at pH 9. In curative treatments,the immersion of inoculated lemons in 1% KS aqueous solution for 30 s reducedgreen and blue molds incidences by around 80%. No wound protection effect wasobserved when wounded lemons were immersed in 3% salt solution before inoculation. Noteworthy, the inclusion of KS in a commercial wax coating effectivelycontrolled green and blue molds, even in decays caused by fungicide resistanceisolates. Together, results encourage the use of KS in lemon postharvest treatments to contribute to the management of resistant strains, which represent amajor challenge in packinghouses worldwide.