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 nano-particles (SNPs) fabricated from debranched cassava starch varying degree of polymerization ((DP) over bar (n)) using nanoprecipitation and microemulsion methods. The high (DP) over bar (n) starch (HDPS) with (DP) over bar (n) > 35 monomers, medium (DP) over bar (n) starch (MDPS) with 15 < <(DP)over bar>(n) < 30) and low <(DP)over bar>(n) starch (LDPS) with (DP) over bar (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.

Automated summary

This study investigated the physicochemical characteristics and digestibility of starch nanoparticles (SNPs) fabricated from debranched cassava starch varying in degree of polymerization using nanoprecipitation and microemulsion methods. SNPs fabricated from high DP starch were well-dispersed and smaller, while those from medium and low DP starch were larger and more aggregated. The SNPs produced by the microemulsion method were larger and more aggregated compared to those by the nanoprecipitation method, with all SNPs showing higher relative crystallinity and more ordered structure than native starch. SNPs fabricated from low DP starch also had higher resistant starch content and lower blood glucose response in mice.