Effect of ultrasonication time on functional and structural properties of faba bean (Vicia faba L.) starch

This study examined the impact of different ultrasonication (USN) times on faba bean starch (FBS). Starch samples were ultrasonicated using an ultrasonic bath for 0, 5, 15, 30, 50, and 60 min. The composition, morphology, structure, and pasting properties of the starches were analyzed. Both native and modified starches exhibited high lightness values (93.93-96.02) and variable amylose contents (31.59-31.75%). The amylose content increased with USN time up to 30 min before declining. USN did not alter the crystallinity pattern of the starches (CB-type). Still, it appeared to damage the crystalline regions, indicated by a reduction in the FTIR peak ratio (1,022/1,045 cm^-1), associated with the amorphous and crystalline areas within starch. These changes affected the pasting properties and functionality of the starches. FBS treated with USN showed reduced syneresis, peak, breakdown, setback, and final viscosities while pasting temperature and peak time increased. This study is the first to subject FBS to varying USN times using an ultrasonic bath, demonstrating the potential to produce FBS with reduced retrogradation, suitable for baked goods. Additionally, it suggests alternative uses for United Kingdom faba beans, currently primarily used in animal feed.