Effects of cooling rate and complexing temperature on the formation of starch-lauric acid-β-lactoglobulin complexes.

The aim of present study was to investigate the effects of cooling rate (3, 5, 10, 15 °C/min) and complexing temperature (50, 60, 70, 80 and 90 °C) on the formation of complexes between wheat starch (WS), lauric acid (LA) and β-lactoglobulin (βLG) in Rapid Visco Analyser (RVA). Higher cooling rate resulted in the higher viscosity peak and final viscosity of WS-LA or WS-LA-βLG complexes than the lower cooling rate during setback of RVA procedure. Results from differential scanning calorimetry (DSC) and Raman spectroscopy showed that larger amount of complexes with lower thermal transition temperatures were formed at higher cooling rate. Higher complexing temperature led to the formation of more complexes with higher thermal transition temperatures. XRD patterns of binary and ternary complexes presented no differences at different cooling rates or different complexing temperatures. We conclude that both higher cooling rate and complexing temperature facilitate the formation of WS-LA and WS-LA-βLG complexes.