OPTIMIZATION OF PROCESS PARAMETERS FOR THE OSMOTIC DEHYDRATION OF BEETROOT IN SUGAR SOLUTION

摘要

Water and sugar transfer were quantitatively investigated during osmoticndehydration of beetroot slices using response surface methodology with thentemperature (25–45C), processing time (30–150 min), sugar concentrationsn(20–60% w/w) and solution-to-sample to ratio (5:1–25:1) being the independentnprocess variables. Quadratic regression equations describing the effectsnof independent process variables on the water loss (WL), solid gain (SG) andnwater reduction were developed. It was found that immersion time and concentrationnof sugar solution were the most significant factors affecting the WLnduring osmotic dehydration of beet root followed by temperature. Effect ofntemperature and time were more pronounced for SG than the concentration ofnsugar solution. The osmotic dehydration process was optimized for water loss,nsolute gain, and weight reduction. The optimum conditions were found to be:ntemperature 33.64C; immersion time 115.37 min; sugar concentrationn27.71%; and solution-to-sample ratio 17.5:1. At these optimum values, waternloss, solid gain and weight reduction were found to be 53.74 (g/100 g initialnsample), 8.34 (g/100 g initial sample) and 45.41(g/100 g initial sample),nrespectively.