Abdolkhalegh Golkar1, Ali Nasirpour1, Javad Keramat1. 1. Department of Food Science and Technology, College of Agriculture, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
Abstract
BACKGROUND: The present study aims to investigate the advantageous effects of wet heating, BLG (β-lactoglobulin)/Ang (Angum gum) ratio, and pH (normal pH of mixed BLG and Ang solutions, pHc > pH > pHΦ1 ) on the emulsifying properties of wet-heated β-lactoglobulin-wild almond gum exudate (Amygdalus scoparia Spach) mixture over those of electrostatic counterparts. RESULTS: Covalent linkage of BLG-Ang conjugates was confirmed by SDS-PAGE and FTIR analysis. Emulsion activity (EA), emulsion stability (ES), and droplet size characteristics of emulsions were significantly (P < 0.05 and P < 0.01) affected by electrostatic/wet-heating, biopolymer ratio, pH, and their interactions. The electrostatic complexes with pHc > pH > pHΦ1 exhibited higher EA and ES values for all the biopolymer ratios investigated than their electrostatic counterparts with pH after mixing. However, these values for the wet-heated samples at pH after mixing were found to be higher than those of the samples subjected to heat treatment at pHc > pH > pHΦ1 . Based on the results obtained, it was concluded that E/1:2/3.80 and W/1:2/6.69 were the two complexes with finer droplet size distributions after preparation (26.72 ± 3.71 and 15.27 ± 1.01 µm, respectively) and after one week of storage at 4 °C (30.71 ± 1.57 and 28.79 ± 0.56 µm, respectively) than others. Apparent viscosities of electrostatic and wet-heated complexes and emulsions made with the complexes were measured. CONCLUSION: Protein-polysaccharide interactions can be used as an efficient way for producing novel emulsifiers/stabilisers after heat treatment.
BACKGROUND: The present study aims to investigate the advantageous effects of wet heating, BLG (β-lactoglobulin)/Ang (Angum gum) ratio, and pH (normal pH of mixed BLG and Ang solutions, pHc > pH > pHΦ1 ) on the emulsifying properties of wet-heated β-lactoglobulin-wild almond gum exudate (Amygdalus scoparia Spach) mixture over those of electrostatic counterparts. RESULTS: Covalent linkage of BLG-Ang conjugates was confirmed by SDS-PAGE and FTIR analysis. Emulsion activity (EA), emulsion stability (ES), and droplet size characteristics of emulsions were significantly (P < 0.05 and P < 0.01) affected by electrostatic/wet-heating, biopolymer ratio, pH, and their interactions. The electrostatic complexes with pHc > pH > pHΦ1 exhibited higher EA and ES values for all the biopolymer ratios investigated than their electrostatic counterparts with pH after mixing. However, these values for the wet-heated samples at pH after mixing were found to be higher than those of the samples subjected to heat treatment at pHc > pH > pHΦ1 . Based on the results obtained, it was concluded that E/1:2/3.80 and W/1:2/6.69 were the two complexes with finer droplet size distributions after preparation (26.72 ± 3.71 and 15.27 ± 1.01 µm, respectively) and after one week of storage at 4 °C (30.71 ± 1.57 and 28.79 ± 0.56 µm, respectively) than others. Apparent viscosities of electrostatic and wet-heated complexes and emulsions made with the complexes were measured. CONCLUSION: Protein-polysaccharide interactions can be used as an efficient way for producing novel emulsifiers/stabilisers after heat treatment.