Sucrose syrup reuse during one‐ and multi‐stage osmotic dehydration of pineapple

Abstract

Multi-stage osmotic dehydration of pineapple with sucrose syrups in gradually increasing concentration was experimentally evaluated and compared to the singlestage dehydration process. Also, osmotic solutions were reused for five osmotic dehydration cycles, without syrup reconditioning treatment. Single- and multi-stage osmotic treatments were carried out for 2 hr at 40 C. Changes in pH, total acidity, and content of soluble solids, water, and ascorbic acid, in fruit and osmotic solutions, were analyzed. Water loss decreased with cycles of syrup reuse in one-stage treatments and remained almost unchanged in multi-stage treatments. Dry matter content of pineapple fruit during four-stage osmotic dehydration cascade (40, 50, 55, and 60 Bx) was increased respect to one-stage dehydration at 40 and 60 Bx. With regard to retention of syrup characteristics, multi-stage dehydration reached a better performance as compared with the single-stage dehydration and through the syrup reuse could become a more economical, environmentally friendly process.