Antifungal activity of mango kernel polyphenols on mango fruit infected by anthracnose

Abstract

Mango cv. Manila kernel ethanolic extract (MKE) was assessed in vitro and in mango cv. Ataulfo fruits for antifungal activity against Colletotrichum brevisporum. An optimum MKE with a total phenolic content of 461.7 mg gallic acid equivalents/g and DPPH• antioxidant activity of 2919.0 μmol Trolox equivalents/g was obtained by applying high intensity ultrasound, using a solid/liquid of 1/20 g/mL and a sonication time of 30 min. The major phenolic compounds in MKE were mangiferin, chlorogenic acid, myricetin, ferulic acid, quercetin, rutin and caffeic acid. In vitro studies revealed that MKE at 3 g/L produced a mycelial growth inhibition of 100% after 9 d and a spore germination of 0% after 20 h. In contrast, the recommended dosage (2 g/L) of the commercial fungicide thiabendazole achieved a mycelial growth inhibition of 67.6% and a spore germination of 51.4% for the same times. Mango fruits immersed in MKE (3 g/L) aqueous solution for 20 min and inoculated with C. brevisporum (105 spores/mL) presented disease lesions of 0 mm, while when immersed in thiabendazole (2 g/L) the disease lesions were of 4.5 mm, both after 9 d. Thus, MKE may be considered as effective antifungal agent.