Impact of β-amylase degradation on properties of sugary maize soluble starch particles.

In this study, β-amylase degradation was used to modulate the fine structure and intestinal biodegradability of sugary maize soluble starch particles. The remnants from extended β-amylase degradation of soluble starch particles exhibited a resistance to the enzyme action, and the particle size ranged from 30 to 105 nm in diameter. The molecular weight distributions of enzyme treated starch particles and their debranched chain length distributions showed β-amylolysis had a thinning effect at the outmost surface of soluble starch particles, resulting in an increase of DP 2-5 chains through shortening of the external long chains. The percentage of α-1,6 linkages reached up to 14.1%. No significant changes occurred in the IR characteristic peaks of modified starch particles, and the primary chemical structure was preserved. The digestion behaviour showed that enzyme treated starch particle had a low digestion rate, which would help designing highly branched nano-particles as a potential delivery carrier for functional components.