Enhanced Resistance to Amylolysis in Rice Kernels through Interaction with Chlorogenic Acid

In this study, rice-phenolic acid complexes were prepared by processing rice kernels in chlorogenic acid (CGA) solutions of different concentrations, followed by heating at different adsorption times. An adsorption treatment of 80 °C for 3 h effectively enhanced the complexation of rice samples with CGA (3.86 mg/g) and imparted antioxidant capacities to the complex. An apparent interaction between CGA and rice starch molecules was suggested by electrospray ionization mass spectrometry analysis. Our results revealed that rice samples were functionalized with CGA by modifying their physicochemical properties by increasing swelling ability (9.1%) and breakdown value (24.7%), and retarding retrogradation (−9.8%). The complexation of rice with a high dose of CGA could significantly reduce in vitro and in vivo starch digestibility by 41.9% and 23.0%, respectively, relative to control. This treatment is considered a potential way to confer rice with an increased resistance to digestion, along with desirable pasting properties.