Stabilization of apple peel by drying. Influence of temperature and ultrasound application on drying kinetics and product quality

Increasing the value of the waste generated by food processing is a must from an environmental and economic point of view. This paper addresses the influence of drying temperature and ultrasound application on the drying kinetics and quality of apple peel (Royal Gala var.). Samples were dried at −10, 30, 50, and 70 °C without and with (50 W) ultrasound application. Color, antioxidant capacity, total phenolics, and ascorbic acid content were measured. Ultrasound application and drying temperature significantly shortened the drying time and affected the quality parameters. The drying carried out at 30 °C with ultrasound application was a fast process that provided samples with good color and antioxidant attributes.