Effect of Centrifugal Force on Chain Length Distributions of Collected Pullulanase‐Digested Starches

ABSTRACT The centrifugation method, involving pullulanase digestion and subsequent centrifugation of the digested starch granules, enabled the collection of starch fractions with long chains. However, the effect of centrifugation on the collection of starch fractions with long chains was not unraveled yet. This study aimed to investigate the impact of centrifugal force (429–6875 g) on the chain length distributions of collected starches. Results showed that pullulanase digestion caused starch reassembly into small particles. Starch collected at 429 g had a crystallinity of 27.57% and an enthalpy of 9.06 J/g. Increasing the centrifugal force (2685–6875 g) significantly increased starch yields, but decreased the average molar mass due to the precipitation of reassembled particles. Centrifugation at 2685–6875 g resulted in precipitation of both amorphous and ordered structures, which reduced crystallinity (24.06%–25.60%) and either decreased or increased enthalpy (6.30–11.23 J/g) of collected starches. Collectively, the collected starches showed no significant differences in chain‐length distributions, but exhibited less shorter chains (20.62%–21.15%) compared to native starch (23.52%). This demonstrated the effective collection of starch fractions with long chains using the centrifugation method, with minimal impact from centrifugal force on chain‐length distribution.