Vacuum impregnation of fresh-cut apples with osmotic solutions containing honey

Abstract

Fresh-cut apples were subjected to mild vacuum impregnation (Vacuum pressure=67.7 mbar). M0: 30 °Brix honey solution (HS); M0.5: HS+0.5% citric acid (CA)+0.5% ascorbic acid (AA); and M1: HS+1% CA+1% AA were used as osmotic solutions. Changes in soluble solids (SS), pH, firmness, color (∆E*ab), total phenolic and vitamin C content, and antioxidant capacity were evaluated on days 0 and 7 of storage at 1.5 °C. Mass transfer parameters were calculated. The best results were obtained with the M1 treatment. Vacuum-impregnated fresh-cut apples gained solids (3.3%) and weight (1.6%) and lost water (1.8%). The following modifications were observed on day 0: an increase of SS (26%), a reduction in firmness (14%), a slight color change (∆E*ab=3.3), a great increase in vitamin C content (31 times higher than in fresh-cut fruits) and increases in total phenolic content and antioxidant capacity (27% and 77%, respectively). On day 7 of storage, an additional reduction of firmness was observed, but the other attributes were maintained or increased. The M1 treatment is an appropriate alternative for processing fresh-cut apples and obtaining improved healthy attributes.