Effect of pH on formation of starch complexes with lauric acid and β-lactoglobulin. (October 2020)

• Record Type: Journal Article
• Authors: Niu, Bin; Chao, Chen; Cai, Jingjing; Yan, Yizhe; Copeland, Les; Yu, Jinglin; Wang, Shuo; Wang, Shujun
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 132(2020)
• Publication Date: 2020-10
• Subjects: Wheat starch -- pH -- Starch-lipid complexes -- Starch-protein-lipid complexes; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2020.109915
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: The aim of present study was to investigate the effect of pH on interactions between macro constituents of foods using wheat starch (WS), lauric acid (LA) and β-lactoglobulin (βLG) in a model system. Results from the Rapid Visco Analyzer (RVA) showed that viscosity peaks appeared during the cooling stage and that their intensity increased gradually from 105 to 5565 cP with increasing pH in the WS-LA binary system. With the WS-LA-βLG ternary system, the cooling viscosity peaks occurred throughout the pH range, and the change in intensity (from 1111 to 3688 cP) was not as evident as in binary systems. Results from differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Raman spectroscopy showed that higher pH promoted the formation of both WS-LA binary and WS-LA-βLG ternary complexes, attributed to greater solubility of LA and higher leaching of amylose. The limited effect of pH variation on the formation of ternary complexes compared with binary complexes is proposed to be due to the pH buffering effect of βLG. Highlights: pH effect on starch-lauric acid (LA)-β-lactoglobulin (βLG) complexes studied. Higher pH promoted the formation of starch-LA and starch-LA-βLG complexes. Increased solubility of LA accounted for the greater amount of complexes formed. Formation of ternary complexes was affected slightly by initial pH of the mixture. Small differences in ternary complexes were attributed to buffering effect of βLG.