Convective drying of mango enriched with phenolic compounds from grape residue flour under different impregnation methods

Abstract

This work evaluated the effect of convective drying of mango impregnated with grape residue flour polyphenols under different vacuum impregnation methods with or without performing osmotic treatment and ultrasound on the global quality of dried mango in relation to chemical, microbiological and sensory aspects. Higher retention of carotenoids, phenolic compounds, and ascorbic acid was obtained with shorter drying times and lower oxygen exposure. Impregnated dried samples submitted to ultrasound-assisted vacuum impregnation showed a higher drying rate, greater retention of carotenoids (6.77 µg/g DM), and softer samples. Greater retention of phenolic compounds (1.84 mg GAE/g DM) was obtained for osmotic dehydration-assisted vacuum impregnation dried mango, while osmosonication-assisted impregnation was able to retain the highest ascorbic acid content (7.05 mg/100 g DM). Sensory evaluation showed that the impregnated samples showed good acceptance. The combination of osmotic dehydration and ultrasound could be a suitable way to produce dried mango impregnated with grape residue polyphenols.

Keywords: Drying; Osmotic dehydration; Ultrasound; Vacuum impregnation.