Lipophilization and molecular encapsulation of p-coumaric acid by amylose inclusion complex

Abstract p- Coumaric acid(CA) is a natural phenolic compound with a wide range of bioactivities, but its tendency to degrade during food processing and storage limits its application in functional foods. Forming amylose-guest inclusion complex is a technique to molecularly encapsulate guest molecules of interest and protect them from adverse environmental challenges. However, CA cannot be encapsulated into the helical cavity of amyloseso this study used a strategy of lipophilization of CA to synthesize hexadecyl p -coumarate (HC), which might complex with amylose. The formation of the amyloseinclusion complex was studied by complementary techniques: differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. To test the photo-stability of CA in the complex, a direct UV irradiation was performed. The in vitro release behavior of CA in the complex was also studied in both simulated gastric and intestinal fluids. The results showed that HC, but not CA, could form inclusion complex with amylose. Compared with CA, HC, and amylose-HC physical mixture, HC complexed with amyloseshowed a significant improvement in photo-stability ( P in vitro digestion. These findings suggest that the amyloseinclusion complex is a promising technique to protect CA in foods during processing and storage and to increase its bioaccessibility.