Effects of Debranching on the Formation of Maize Starch-Lauric Acid-β-Lactoglobulin Complexes.

In this study, the effects of debranching on the structure and properties of the starch-lauric acid (LA)-β-lactoglobulin (βLG) complex were studied. Gel permeation chromatography and high-performance anion-exchange chromatography showed that debranching of amylopectin generated short linear chains, which increased in proportions with debranching time. Analyses from differential scanning calorimetry, laser confocal micro-Raman spectroscopy, and X-ray diffraction showed that debranching promoted the formation of starch-LA and starch-LA-βLG complexes, as characterized by the increased enthalpy changes and crystallinity and decreased full width at half maximum of the band at 480 cm-1. Debranching treatment for 6 and 18 h promoted complexation between starch and LA, while extensive debranching was unfavorable for the formation of starch-LA complexes. Similar results were also observed for the starch-LA-βLG complexes. Starch-LA-βLG complexes had more type II and less type I crystallites than starch-LA complexes. From this study, we conclude that debranching of starch favors the formation of starch-LA and starch-LA-βLG complexes, with more type II crystallites formed in starch-LA-βLG complexes.