Effects of Starch Addition on KGM Sol’s Pasting, Rheological Properties, and Gel Texture

Abstract

Konjac tofu is an irreversible gel formed by removing the acetyl group from konjac glucomannan (KGM) through alkaline heating. This type of food is low in calories, filling, and healthy, making it popular in the market. However, pure konjac tofu has a hard texture and lacks flavor when heated. To improve its taste and appearance, the effects of three varieties of native starch, including corn starch (CS), Canna edulis Ker starch (CKS), and potato starch (PS), on the formation of pasting and rheological properties of the KGM sol were investigated. Konjac tofu samples that incorporated different types and quantities of starch were prepared and analyzed in terms of structure, texture, dehydration, and flavor, with pure konjac tofu serving as a reference. The findings revealed that KGM mixed with a concentration of 4.2% CS, or 0.85% CKS, or 0.85% PS of the total mass produced a gel with the highest viscosity and a steady structure. Texture profile analysis indexes of these combinations were superior to pure KGM, and the konjac-starch tofu had a lamellar network structure. Thus, konjac tofu with the addition of starch has a higher quality texture, lower dehydration, and improved flavor compared to pure KGM gel.