An insight into the mechanisms of foxtail millet bran polysaccharides retarding the digestibility of millet starch by in vitro simulated digestion

The influence of foxtail millet bran polysaccharides (MPs) on millet starch (MS) digestion was investigated in the three aspects (MPs, MP-MS gel properties, the interactions between MPs and MS). The results showed that MPs with a higher Mw (58-2552 kDa), a narrower Mw distribution (1.85-9.53) and greater digestive enzyme inhibition could rely on the stability of the MP-MS gel to affect starch digestibility. The stronger hydrogen bonding between MPs and MS was beneficial to form a stable gel network structure. Moreover, the adhesiveness, hardness, and springiness of MP-MS gel and the formation of lamellar structure reduced contact with digestive enzymes. The presence of glucose and the increase of digestive juice viscosity inhibited digestive enzymes diffusion and reduced starch digestibility. This study revealed the key factors and influence pathways in the digestion of MP-MS gel, providing new ideas for the development of low-glycemic index starch foods.