Promoting starch interaction with genistein to slow starch digestion using an antisolvent method.

ABSTRACT

Genistein could interact with starch to slow starch digestion by forming starch-genistein complexes. However, genistein had low solubility in water, which hindered the interaction with starch and therefore the formation of the complexes. This study presented a pathway to promote the formation of starch-genistein complexes using an antisolvent method in two steps: (i) adding ethanol to the solution containing starch and genistein to increase genistein solubility, and (ii) evaporating ethanol from the solution to promote genistein interaction with starch. The complexes prepared using this antisolvent method had higher crystallinity (9.45 %), complex index (18.17 %), and higher content of resistant starch (RS) (19.04 %) compared to samples prepared in pure water or ethanol-containing aqueous solution without ethanol evaporation treatment (these samples showed crystallinity of 6.97 %-8.00 %, complex index of 9.09 %-11.4 2%, and RS of 4.45 %-14.38 %). Molecular dynamic simulation results confirmed that the changes in solution polarity significantly determined the formation of starch-genistein complexes. Findings offered a feasible pathway to efficiently promote starch interaction with genistein and in turn mitigate starch digestibility.