Effects of different sources of proteins on the formation of starch-lipid-protein complexes

In the present study, the influence of different sources of proteins on the formation of complexes with starch and lipid were investigated. A model system containing wheat starch (WS), palmitic acid (PA) and four proteins (whey protein isolate, egg white protein, soy protein isolate and pea protein isolate) was used to prepare the complexes by Rapid Visco Analyzer. The addition of PA in the pasted WS-protein systems resulted in higher cooling viscosity compared to the pasted WS-PA systems, which was interpreted as being due to the formation of WS-PA-protein complexes. Analyses from differential scanning calorimetry, X-ray diffraction and Raman spectroscopy showed that more complexes were formed in WS-PA-protein systems than in WS-PA systems, especially in the WS-PA-whey protein isolate. The better emulsifying action of whey protein isolate was proposed to be accountable for the greater amounts of complexes formed compared to other three proteins. This study provides important information about the formation of starch-lipid-protein complexes in regard to the selection of proteins for food processing.