Effects of Osmotic Dehydration-Assisted Freezing at Different Pressure Rates on Mass Transfer and Quality of Fresh-Cut Apple

Abstract

This study aims to enhance the preservation of fresh-cut apple slices by applying osmotic dehydration in sucrose solutions prior to high-pressure shift freezing (HPSF). Apple slices (1 × 1 × 1 cm) were osmotically dehydrated under varying sucrose concentrations (45°Bx, 55°Bx, 65°Bx), temperatures (25°C, 35°C, 45°C), and durations (30, 60, 90 min) before freezing at pressures of 200 and 240 MPa. Mass transfer (water loss, solid gain), drip loss, total soluble solids (TSS), sensory qualities (color, sweetness, flavor, texture, acceptability), and microstructural changes (via light microscopy) were assessed using standard methods, with statistical analysis applied to evaluate differences. Optimal pretreatment at 65°Bx, 35°C, and 30 min followed by freezing at 240 MPa increased TSS and reduced drip loss by 93% compared to untreated samples. Sensory qualities and microstructure were significantly better preserved in treated samples (p ≤ 0.05). The study demonstrates that combining osmotic dehydration and HPSF under optimized conditions enhances fresh-cut apple preservation, offering valuable applications for the food industry.