The enhancing effects of locust bean gum and xanthan gum on the digestibility of potato starch under thermal treatments

Abstract

Abstract Locust bean gum (LBG) and xanthan gum (XG) played regulatory roles in the digestibility of potato starch (PS) during thermal treatments. The relative physicochemical characteristics were investigated through an in vitro digestibility test, Fourier transform infrared spectroscopy, and rapid viscosity analyzer, as well as scanning electron microscopy. PS combined with LBG and XG was heated successively under normal pressure and high pressure to obtain the AT‐PLX sample. Compared to PS, the AT‐PLX sample had a lower hydrolysis rate, larger resistant starch content, decreased viscosity, and partly covered microscopic morphology. The changes might be attributed to the network formed via hydrogen bonds between PS and LBG/XG. Besides, the fluctuation rates of breakdown and setback values (FRBD and FRSB, respectively) were proposed as novel indicators of stability under heat and retrogradation to evaluate the pasting property comprehensively and accurately. The AT‐PLX sample likely belonged to the stable soft gel with a stronger cross‐linking ability due to the lower FRSB and higher FRBD values, which also contributed to its lowest digestibility. These findings would provide an alternative and friendly strategy for the development of starch‐based soft food or material and have the potential to be utilized in nutrient delivery or special diets.