Adding gamma-aminobutyric acid to modulate the in vitro digestive characteristics of tapioca pearls

The effects of gamma-aminobutyric acid (GABA) on gelatinization, pasting and rheological properties of the blend of hydroxypropyl distarch phosphate and tapioca starch were studied to examine the in vitro digestive characteristics of tapioca pearls. The addition of higher GABA contents resulted in lower starch hydrolysis rates and release rates of GABA during the digestion process, which indicated that GABA could modulate the digestive properties of tapioca pearls. RVA and DSC results showed that GABA inhibited the gelatinization of mixed starch and hindered the recrystallization of starch, leading to enhanced thermal stability and reduced viscosity. Also, the addition of GABA limited the water absorption and expansion of starch to some extent, resulting in decreased elastic and viscous moduli. XRD results showed that GABA changed the crystal structure of original mixed starch with reduced crystallinity. Moreover, the addition of GABA resulted in a reduction of RDS content and a significant increase in RS, which would provide potential applications for GABA in starchy health food.