Table of Contents
International Journal of Microwave Science and Technology
Volume 2013 (2013), Article ID 207308, 11 pages
http://dx.doi.org/10.1155/2013/207308
Research Article

Microwave-Osmotic Dehydration of Cranberries under Continuous Flow Medium Spray Conditions

Department of Food Science and Agricultural Chemistry, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Montreal, QC, Canada H9X 3V9

Received 26 March 2012; Accepted 5 December 2012

Academic Editor: Tanmay Basak

Copyright © 2013 Derek Wray and Hosahalli S. Ramaswamy. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Microwave-osmotic dehydration of cranberries was evaluated under continuous flow medium spray (MWODS) conditions after some pretreatments. A central composite rotatable design was used with three input variables at five levels (temperature, 33°C–67°C; sucrose concentration, 33°B–67°B; and contact time, 5–55 min). Responses were moisture loss (ML), solids gain (SG), and weight reduction (WR) as well as color and texture parameters. The responses were related to process variables using response surface methodology and statistical analysis: each model was tested for lack of fit to assure nonsignificance and each process variable was tested for significance . Temperature was found to have the most prominent effect as it was significant with all drying (ML, SG, and WR) and quality (hardness and chewiness) parameters, while contact time was found to be significant with ML and WR. Concentration wasn’t found to be significant for any response. Increasing skin pretreatment severity generally promoted SG but had little effect on ML. The exception was chemical peeling, which favored ML but had no effect on SG. Overall, MWODS enables food dehydration in a much faster period of time than conventional osmotic dehydration (COD), while specifically promoting moisture loss over solids gain.