The effect of ultrasound pretreatment on quality attributes of freeze‐dried quince slices: Physical properties and bioactive compounds

The study was conducted to examine the effect of ultrasound (US) pretreatment on physical and chemical/nutritional attributes of freeze‐dried quince slices. The quince fruits were washed, hand‐peeled and cut with a dimension of 1 cm (L) × 0.2 (W) cm × 1 cm (H). The quince samples were treated in an ultrasonic bath in three different times which were 10, 20, and 30 min. Untreated and ultrasonically pretreated quince samples were dried in a freeze dryer. Freeze‐dried samples were analyzed in terms of physical properties such as shrinkage, rehydration, color, water activity, and hardness and bioactive compounds including total phenols, ascorbic acid, and antioxidant capacity. A significant difference was observed among untreated and ultrasonically pretreated quince samples. The freeze‐dried quince slices treated with a US (especially 20 min—treatment) showed a higher preservation of bioactive compounds in addition to improved physical properties compared to the untreated quince samples. In overall, US pretreatment is a promising process as demonstrated in current research by its capability to better retain freeze‐dried quince quality in terms of physical and chemical properties. Practical Applications The freeze drying of quince fruit with the aid of US pretreatment was investigated. A significant development in the quality preservation of freeze‐dried of quince slices with an US‐pretreatment was accomplished. This research will contribute a useful technique to produce freeze‐dried quinces with a significantly enhanced product quality. Drying of quince samples with a freeze drying in addition to US‐pretreatment might be applied to get a high‐quality fruit with an improved bioactive compounds and physical property.