Variation in the Physical and Functional Properties of Yam (Dioscorea spp.) Flour Produced by Different Processing Techniques
Nurdi Setyawan, John Solomon Maninang, Sakae Suzuki, Yoshiharu Fujii
Foods
Abstract
Research on the processing of yam (<i>Dioscorea</i> spp.) into flour is aimed at optimizing techniques to obtain a material with high physicochemical and functional properties. The present study investigates the effect of the processing techniques on the levels of inulin, organic acids, total phenolics (TP), antioxidant capacity, and polyphenol oxidase (PPO) and peroxidase (POD) activities, as well as on the physicochemical properties of flour derived from two yam species-<i>Dioscorea esculenta</i> and <i>Dioscorea bulbifera</i>. All tubers were peeled and sliced, then subjected to different processing techniques through blanching, soaking, and drying. The results revealed that freeze-drying appears to be the best technique in achieving the highest whiteness index of yam flour. This coincided well with the low phenolics content and POD activity, which suggests a reduced enzymatic browning reaction in the freeze-dried yam flour. On the other hand, chemical analyses showed that <i>D. esculenta</i> and <i>D. bulbifera</i> flours have the highest levels of inulin (23.0 and 27.8 g/100 g DW, respectively) and succinic acid (7.96 and 7.65 g/100 g DW, respectively) in the samples subjected to direct oven-drying. Oven drying without pretreatment neither blanching nor water steeping maintained antioxidant activity in the flour derived from both <i>D. esculenta</i> and <i>D. bulbifera</i>.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
direct oven-drying maintains antioxidant activity in yam flour
“Oven drying without pretreatment neither blanching nor water steeping maintained antioxidant activity in the flour derived from both <i>D. esculenta</i> and <i>D. bulbifera</i>.”
freeze-drying reduces phenolics content and POD activity
“This coincided well with the low phenolics content and POD activity, which suggests a reduced enzymatic browning reaction in the freeze-dried yam flour.”
D. esculenta and D. bulbifera flours have highest levels of inulin and succinic acid
“chemical analyses showed that <i>D. esculenta</i> and <i>D. bulbifera</i> flours have the highest levels of inulin (23.0 and 27.8 g/100 g DW, respectively) and succinic acid (7.96 and 7.65 g/100 g DW,...”