Effects of peanut oligopeptides on the pasting properties of potato starch and digestive characteristics of dry, flat potato starch noodles

In this study, we developed dry, flat potato starch noodles with an ideal taste and low digestibility. Peanut oligopeptide and potato starch were combined to form dry, flat potato starch noodles containing different peanut oligopeptide contents using a steam-slice method. Adding 5 % and 10 % peanut oligopeptides maintained the dry, flat starch noodles' quality. Scanning electron microscopy (SEM) analysis showed that dry, flat starch noodles containing peanut oligopeptides had more pores with pore sizes ranging from 0.30 μm to 2.00 μm. X-ray diffraction (XRD) results showed that peanut oligopeptide promoted the recrystallization of amylopectin during the retrogradation process after gelatinization, and the crystallinity of noodles ranged from 4.31 % (control noodles) to 18.24 % (noodles containing 10 % peanut oligopeptides). An in vitro simulated digestion test showed that the slowly digestible starch and resistant starch contents of noodles containing 10 % peanut oligopeptides were 18.24 % and 22.03 %—significantly higher than control starch noodles (14.88 % and 9.9 %, respectively). Therefore, when peanut oligopeptides were added to dry, flat starch noodles, it was a promising material for lowering blood sugar levels after meals.