Insights into the Formation and Structures of Starch Protein Lipid Complexes

The aim of the present study was to characterize the multiscale structures of ternary complexes of a model system of starch, fatty acid (FA), and beta-lactoglobulin (beta LG) prepared using a Rapid Visco Analyzer (RVA). The addition of beta LG to starch-lauric acid or starch-oleic acid RVA pastes resulted in the increased intensity or occurrence of a new viscosity peak during cooling when the RVA protocol was repeated. The viscosity peak was attributed to the formation of starch-beta LG-FA complexes. Differential scanning calorimetry (DSC) results showed clearly that the starch-beta LG-FAs complex was formed as gelatinized starch was cooled in the presence of beta LG and FAs. The results of Raman, FTIR, and X-ray diffraction analyses showed that starch can interact with beta LG and FAs to form a ternary V-type crystalline complex, which had a greater short-range molecular order and higher relative crystallinity compared with those of the binary starch-FA complex. The present study provided insights into the structure of a model starch protein fatty acid complex as an example of what might occur during food processing.