Effects of Fatty Acids with Various Chain Lengths and Concentrations on the Structure, Physicochemical and Emulsification Properties of Cassava Starch-Fatty Acid Complexes

Abstract

This study aims to treat cassava starch (CS) with fatty acids (FAs), namely lauric acid (LA), myristic acid (MA), and arachidic acid (AA), at concentrations of 5.0%, 10.0%, and 15.0% (w/w), to form complexes (CS-FAs) and explore their applications in emulsion systems. The X-ray diffraction, Fourier transform infrared spectroscopy, and Complex index findings revealed that all FAs formed complexes with CS. Scanning electron microscope (SEM) images showed the complexes as either spherulites or lamellae crystals. The LA-starch complex demonstrated the best composite ability and stability. Contact angle measurements indicated a positive correlation between CS-FAs hydrophobicity and FAs concentration. Additionally, emulsions produced with LA-10% and LA-15% showed improved emulsifying capacity and stability. Rheological results showed that emulsions with high-concentration CS-FAs had increased viscosity, which was crucial for maintaining emulsion stability. Our findings revealed the mechanism of CS-FAs complexation and provided meaningful insights into the practical application of CS-FAs in emulsion systems.

Keywords: Fatty acid concentration, Chain length, Cassava starch-lipid complexes, Pickering emulsion stability