Effectiveness of partially hydrolyzed rice glutelin as a food emulsifier: Comparison to whey protein

• Published in: Food chemistry Vol. 213; pp. 700 - 707
• Main Authors: Xu, Xingfeng, Zhong, Junzhen, Chen, Jun, Liu, Chengmei, Luo, Liping, Luo, Shunjing, Wu, Lixin, McClements, David Julian
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.12.2016
• Subjects: Emulsifying Agents - analysis; Emulsifying Agents - chemistry; Emulsion; Emulsions - analysis; Emulsions - chemistry; Environmental stress; Glutens - analysis; Glutens - chemistry; Hydrogen-Ion Concentration; Hydrolysis; Oryza - chemistry; Rice glutelin; Stability; Whey protein isolate; Whey Proteins - analysis; Whey Proteins - chemistry; Emulsion; Stability; Whey protein isolate; Rice glutelin; Environmental stress
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.07.047

•H-RG has potential as a food emulsifier for certain applications.•O/W emulsions containing small droplets (d<200nm) could be produced.•H-RG had a higher surface load than whey protein isolate (WPI).•H-RG emulsions were stable at relatively high pH, low salt, and low temperature.•H-RG emulsions were less stable than WPI emulsions to environmental stresses. The emulsifying properties of partially hydrolyzed rice glutelin (H-RG, 2% degree of hydrolysis) were compared to those of whey isolate protein (WPI), a commonly used protein-based emulsifier. The surface load of WPI (1% emulsifier, d32=167.5nm) was 2.8 times lower than that of H-RG (3% emulsifier, d32=159.0nm). Emulsions containing WPI-coated lipid droplets had better stability to pH changes (2–8), NaCl addition (0–500mM) and thermal processing (30–90°C, 0 or 200mM NaCl). Nevertheless, H-RG emulsions were stable over a range of conditions: pH 6–8; NaCl≤200 (pH 7); temperatures≤90°C in the absence of salt (pH 7); and temperatures≤50°C in the presence of 200mM NaCl (pH 7). This study indicates that H-RG may be utilized as a natural emulsifier in the development of label-friendly emulsion-based food products, but that further work is needed to increase the range of applications.