Consumer acceptability, physicochemical characteristics, and bioactive compounds of sweet potato roots subjected to osmotic dehydration

Abstract

Sweet potato dehydration is a way of increasing shelf life, modifying and adding value to the final product. However, some of the compounds of nutritional interest may be lost during processing. Thus, this work evaluates different dehydration treatments for sweet potato, and determines the best condition for a quality product. Two sweet potato genotypes (UGA 127 and UGA 34) were first subjected to osmotic dehydration using a 65% sucrose solution or a 2% sodium chloride solution (NaCl), both for 5 hours, being compared with the control treatment. Subsequently, the samples were oven dried at 65 °C for 6 hours. Sweet potatoes were analyzed for sensory characteristics (color, flavor, crispness, aroma, overall acceptability, and purchase intent), physicochemical characteristics (color, titratable acidity, soluble solids), bioactive compounds (β-carotene, phenolic, ascorbic acid), and antioxidant capacity. Potatoes dehydrated with 65% sucrose were well accepted by the tasters. The soluble solids content and soluble solids/titratable acidity ratio were higher for sweet potatoes treated with 65% sucrose. Genotypes differed significantly for luminosity, and the highest average was found for UGA 127, indicating that potatoes processed from this root had a lighter coloration. The content of bioactive compounds varied as a function of the different treatments and genotypes; in general, the highest levels were found in the control and 65% sucrose treatments. Genotype UGA 127 treated with 65% sucrose proved to be a good marketing alternative for small farmers.