Use of transglutaminase at different concentrations and incubation times for quality improvement of high-fiber cracker fortified with soybean hulls

Soybean hull powder (SHP), a by-product of soybean oil extraction rich in dietary fiber and antioxidants, was used to develop high-fiber crackers. Nutritional, physical and physicochemical quality of SHP and soft wheat flour was examined. Nutritional, textural, other physical quality, and sensory acceptability of the crackers were evaluated and compared. Incorporating 15 % SHP into crackers led to approximately 7.5-fold and 1.2-fold increases in dietary fiber content and antioxidant capacity, respectively, compared to the control crackers without SHP. Despite reducing waste and boosting nutrient intake, consumer acceptance remains low due to their compromised texture. Specifically, compared to the control, all SHP-fortified cracker samples had less puffiness and breaking strength, while the overall acceptability of 15 % SHP cracker sample was below the acceptable threshold. The quality of wheat crackers is strongly influenced by the gluten content and the degree of gluten network cross-linking, and since soybean hulls contain protein levels comparable to wheat flour, any method that can enhance protein cross-linking from these raw materials in high-fiber cracker formulations represents a noteworthy approach. As the transglutaminase concentration varied from 0 to 1.5 U/g, the breaking strength of high-fiber crackers increased by 20 %, and the overall acceptability was dramatically ameliorated; besides, extending incubation time from 12 to 24 min did not affect overall acceptability of the crackers, whereas further increase in treatment time to 36–48 min led to a decrease in sensory quality. Overall, the incorporation of 15 % SHP and transglutaminase treatment at 1 U/g and 12 min produced high-fiber crackers that not only met nutritional benefits but also satisfied sensory acceptability from consumers, thereby encouraging the use of these functional foods.