Konjac glucomannan fiber interferes with chyme digestion: Physical properties and freeze-thawing study

Insoluble konjac fiber (KF) exhibits a high absorption capacity, promotes health by influencing food digestion, and its impact mechanism warrants further investigation. This study examined the impact of KF prepared at different freeze-thaw (FT) cycles on chyme digestion by examining the physical properties of KF (hydration, absorption, swelling, and texture properties). The results showed that FT cycles reduced the pore size and volume, increased the bound water content, and enhanced the hardness (177.77 N) and chewiness (130.58 N) of KF. The volume reduction compromised KF's capacity to modulate gastric chyme digestion. KF prepared through FT procedure significantly inhibited starch hydrolysis (inhibition rate = 35.51 %), which is attributed to its absorption ability towards hydrolytic enzymes (absorption rate = 17.35 %). With an increase in the number of FT cycles, the inhibitory effect of KF on starch digestion was intensified. Absorption emerged as the pivotal factor affecting the efficiency of chyme digestion among the evaluated physical properties of KF. These findings provide new perspectives for further exploring the relationships between konjac fiber and its health benefits and pave the way for the development of new technologies for konjac fiber.