Solid wastes generated from the industrial processing of pineapple are favourable raw materials for obtaining antioxidants and bioactive compounds because of their low cost and the possibility of reducing environmental problems caused by waste disposal. Hence this study aims to investigate the microwave drying characteristics of pineapple waste and its effect on the ascorbic acid content and proteolytic enzyme activity. Pineapple stem and core were subjected to microwave drying process at three different power intensities (380 W, 530 W and 680 W). Dried samples were then analysed for ascorbic acid concentration and proteolytic enzyme activity. Results show that ascorbic acid concentration in the stem sample dried at 530 W was the highest. The proteolytic enzyme activity was found to be the highest in pineapple core dried at 380 W. As the power level increased, more proteolytic enzyme denaturated and resulted in the reduction of enzyme activity. Microwave drying could remarkably preserve both pineapple stem and core while retaining the ascorbic acid content and proteolytic enzyme activity of dried pineapple wastes.
