Effects of Debranching on the Formation of Maize Starch–Lauric Acid−β-Lactoglobulin Complexes
Jingjing Cai, Chen Chao, Bin Niu, Jinglin Yu, Les Copeland, Shuo Wang, Shuo Wang, Shujun Wang, Shujun Wang
Abstract
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.