Morphology, crystalline structure and digestibility of debranched starch nanoparticles varying in average degree of polymerization and fabrication methods.

The objective of this study is to investigate physicochemical characteristics and digestibility of starch nanoparticles (SNPs) fabricated from debranched cassava starch varying degree of polymerization (DP¯n) using nanoprecipitation and microemulsion methods. The high DP¯n starch (HDPS) with DP¯n > 35 monomers, medium DP¯n starch (MDPS) with 15 < DP¯n < 30) and low DP¯n starch (LDPS) with DP¯n < 10 were used. The SNPs fabricated from the HDPS were well-dispersed and smaller size, whereas those prepared from the MDPS and LDPS had bigger size and more aggregation. The SNPs produced by the microemulsion method were larger and more aggregated than those by the nanoprecipitation method. All SNPs exhibited the V + B-type X-ray diffraction pattern with higher relative crystallinity and more ordered structure than native starch. The SNPs fabricated from the LDPS also had higher amount of RS with lower blood glucose response in mice than those from the MDPS and HDPS.