Gluten-free starch noodles from sweet potato with reduced starch digestibility and enhanced protein content.

Sweet potato starch (SPS) noodles despite being gluten-free, has low nutritional value as it lacks proteins, minerals, vitamins etc. The objective of this study was to develop gluten-free starch noodles from sweet potato with enhanced protein content through fortification with whey protein concentrate (WPC) and to study the effect of protein fortification and blending SPS with banana (BS), cassava (CS) and mung bean (MBS) starches and annealed cassava starch (ACS) in reducing the starch digestibility. The highest protein retention in cooked noodles was obtained for 20 % WPC fortification, while the lowest starch digestibility was observed for 40 % BS fortified noodles followed by 50 % ACS fortified noodles. The highest resistant starch (RS) retention was for BS and ACS fortified noodles, which also had medium glycemic index of 66.3 (BS) and 67.2 (ACS). High sensory scores were obtained for the BS and 20 % WPC fortified noodles. The study showed that protein and/or BS fortification with SPS could enhance the acceptability as well as functional value of SPS noodles.