The effect of the addition of soluble fibers (polydextrose, corn, pea) on the color, texture, structural features and protein digestibility of semolina pasta

Abstract

Wheat durum pasta was added with dietary fiber from green pea, corn or polydextrose at levels of 6, 12 and 18 g/100 g. Texture analysis showed that the dietary fiber produced cooked pasta with increased hardness, reduced elasticity and cohesiveness, the effect was magnified by the level of fiber content. The optimum cooking time decreased with the addition of dietary fiber, while the cooking loss exhibited an increase of 9–11% for dietary fiber contents of 18 g/100 g. The yellowness of pasta was non-significantly affected by dietary fiber contents up to 12 g/100 g. FTIR analysis of the cooked pasta indicated that dietary fiber affected only the secondary structure of proteins, which discarded chemical interactions between the dietary fiber and proteins. The in vitro protein digestibility (IVPD) was decreased from about 91.87% for the control pasta to 32.40, 54.05 and 25.98% for the green pea fiber, corn fiber and polydextrose added at an 18 g/100 g level, respectively. A principal component analysis showed that the IVPD was inversely aligned with the dietary fiber content. It was proposed that the dietary fiber limited the IVPD by acting as a physical barrier obstructing the action of proteolytic enzymes.