Structural and physicochemical properties of thermal-mechanical combined lipid modified wheat starches and their...

Previous studies have explored the structural and functional properties of starch-lipid complexes; however, their binding states and application in model dough remain unknown. In this study, monoolein and rapeseed oil were used to elucidate this question. The results indicated that thermal-mechanical treatment promoted the formation of V-type monoolein-starch complexes and its bound lipid content increased from 6.5 mg/g to 41.0 mg/g, whereas rapeseed oil hardly formed the complexes with starch. After thermal-mechanical treatment, the starch morphology was destroyed, monoolein-starch showed a higher relative crystallinity (18.2%) than rapeseed oil-starch (8.6%), whilst lipid types influenced their gelatinization degree, with values of 33.9% and 66.9%, respectively. Moreover, transient thermal-mechanical treatment did not induce the formation of oxylipids in the starch-lipid mixtures. The monoolein-starch complexes obviously tailored the gelatinization behavior and digestibility of model dough. Our results provide strategies for the preparation of lipid-modified starches with promising application potential in the starchy food industry.