Debranched rice starch with highly enriched B1 chains enhanced the encapsulation of aroma molecules

Three debranched rice starch (DBS) with varying chain lengths were isolated in the hydrolysate solution-to-ethanol ratio of 1:3, 1:1.5, and 1:0, which were named as DBS1:3, DBS1:1.5, and DBS1:0, respectively. Three C8 aroma molecules with distinct functional groups, namely 1-octanol, 1-octen-3-ol, and γ-octalactone, were selected as the research objects. DBS1:1.5 exhibited a narrow chain length distribution and the content of B1 chains with degree of polymerization 13-24 was 58.77 %. The inclusion rates of DBS1:1.5 with the aforementioned aroma molecules ranged from 42.30 % to 68.09 %, which were higher than those of DBS1:0 (8.72 %-12.16 %) and DBS1:3 (24.26 %-48.24 %). Additionally, DBS1:1.5-aroma complexes showed high crystallinity, short-range order, and thermal stability. DBS1:0-aroma and DBS1:3-aroma complexes possessed a hybrid crystal structure combining B-type and V-type arrangements, characterized by low short-range order and thermal stability. The mechanism by which aroma molecules affected their interaction with starch was associated with their structure and hydrophobicity. High hydrophobicity and linear structure facilitated the interaction of 1-octanol with starch, thereby enhancing its encapsulation effect. Contrastingly, the low hydrophobicity and large size of the lactone ring attenuated the interaction between γ-octalactone and DBS. This research held significant implications for improving aroma quality in starch-based food processing.