Effect of Pre-treatments on Shelf Life and Quality of Dried Pineapples (Ananas comosus)

Abstract

This study aims to determine the effect of different pre-treatment and freezing on the quality of dehydrated pineapple using a food dehydrator with a convective drying method. The variations of pre-treatment conducted include control variation (K), immersion in sucrose solution (G), sucrose-citric acid mixture (GS), citric acid (S), thermal blanching (B), and kapur sirih or betel lime solution (KS), with and without freezing process before drying. The S variation resulted in the best shelf life of dried pineapple, lasting 106 days under room conditions using 0.75% citric acid solution. The shelf life of dried pineapple with pre-treatments K, G, GS, B, and K, respectively, were 61, 49, 33, 72, and 20 days. Drying and all types of pre-treatments resulted in a darker colour compared to fresh pineapple. Drying and all types of pre-treatments also yielded higher firmness values compared to fresh pineapple. Freezing prior to drying resulted in a darker colour for dried pineapple compared to unfrozen dried pineapple. Freezing prior to drying also yielded a softer texture compared to unfrozen dried pineapples. According to a group of 32 untrained panellists in the age group of 20-24 years old, the G variation was the most preferred variation of dried pineapple.