Textural And Sensory Qualities Of Bread Supplemented With Sweet Potato Starch Containing High Resistant Starch

Abstract

The resistant starch plays an important role in preventing from the accumulation of fat, reducing diabetes, lowering the risk of heart disease, and giving positive effect on colonic health. This study was carried out to investigate physical characteristics, textural properties and sensory qualities of bread made from wheat flour with or without supplementing with 20% of native or modified sweet potato starch. The starch, isolated from sweet potato tubers, was treated with a combination of citric acid and heat – moisture to improve resistant starch content. Then, three kinds of breads, made from 100% wheat flour, 80% wheat flour and 20% native sweet potato starch, and 80% wheat flour and 20% modified starch, were evaluated for their physical characteristics (loaf weight, loaf volume and specific volume), textural properties (hardness, springiness, and gumminess) and sensory qualities to know the effects of native and modified starch supplementation on quality of breads. The purity of starch was 98.99% and the modified starch contained 40.46% of resistant starch. Physical characteristics of composite bread showed more loaf weight, but less loaf volume and oven spring; while texture profile showed more hardness and gumminess as compared with control sample. However, the sensory qualities of breads supplemented with native or modified starches were not significantly different from those of the bread control. As a result, it may be concluded that a supplementation of 20% modified starch containing high resistant starch into wheat flour was moderately acceptable. Key words: sweet potato starch, resistant starch, supplemented bread, physical characteristics, textural properties, sensory qualities