Structural, digestive, and physicochemical properties of heat-moisture treated potato starch complexed with peptides...

In this study, the hydrated potato starch (PS) was separately mixed with extracted Huizhou ham trimmings-derived peptides (HTPs) powder, sealed in Pyrex glass bottles, and treated at 110 °C. The PS-HTPs complexes were observed by scanning electron microscopy, showing aggregation and flat surfaces. According to X-ray diffraction and Fourier Transform infrared spectroscopy analysis, the crystal structure of the PS-HTPs complexes transformed from the native B-type to a combined B- and A-type pattern, and the interaction between PS and HTPs was hydrogen bond (3446 cm^-1) and hydrophobic interaction (989 cm^-1). X-ray photoelectron spectroscopy revealed that the negative binding energy shifts of both N1s and O1s peaks clearly demonstrate hydrogen bond formation between peptides (-NH₂) and starch (-OH). Compared with native potato starch, the content of slowly digestible starch and resistant starch in the PS-HTPs complexes respectively increased by 5.25% and 23.28%, and peak blood glucose levels in C57 mice decreased by 42.0% following consumption of the PS-HTPs complexes. The interaction between PS and HTPs significantly reduced the in vitro digestibility of potato starch and significantly attenuated the postprandial glycemic response in vivo. The PS-HTPs complexes exhibited improved viscosity, a reinforced gel network, and enhanced thermal stability. Furthermore, the swelling power and solubility showed that PS-HTPs complexes had lower swelling power and higher solubility after heat-moisture treatment. These results reveal mechanistic insights into starch and polypeptide interactions, which can inform the development of carbohydrate foods that regulate blood glucose fluctuations.