Preparation of starch nanoparticles by jet cavitation and enzymatic hydrolysis and their application in starch films

Potato starch was subjected to jet cavitation, freeze-thaw, ultrasound, acid, and enzymatic treatments to prepare starch nanoparticles. Enzymatic hydrolysis after jet cavitation pretreatment was found to be efficient. Therefore, enzymatic hydrolysis conditions of jet cavitation-treated starch were optimized. The smallest starch nanoparticles were obtained when the enzyme concentration was 66.68 nkat, starch concentration was 10 g/dL, and enzymatic hydrolysis duration was 3 h. The prepared starch nanoparticles showed a mixture of B and V-type crystalline structures with reduced relative crystallinity. A combination of potato starch nanoparticles and tea polyphenols was incorporated into potato starch-based edible films. The elongation at break of edible films significantly improved with the incorporation of starch nanoparticles. Additionally, the water resistance, tensile strength, and antioxidant activity of films improved with the addition of starch nanoparticles and tea polyphenols. Furthermore, the FTIR analysis indicated comparable spectra for all the starch-based films, except for the tea polyphenols-incorporated film, which exhibited a distinct band at 1605 cm−1.