| Title: | "Effect of milk protein composition on physicochemical properties, creaming stability and volatile profile of a protein-stabilised oil-in-water emulsion" |
| Author(s): | Loi CC; Eyres GT; Birch EJ; |
| Address: | "Department of Food Science, University of Otago, Dunedin, New Zealand. Electronic address: marcus.loi@postgrad.otago.ac.nz. Department of Food Science, University of Otago, Dunedin, New Zealand" |
| DOI: | 10.1016/j.foodres.2019.02.026 |
| ISSN/ISBN: | 1873-7145 (Electronic) 0963-9969 (Linking) |
| Abstract: | "Casein, whey proteins and monoglycerides are emulsifiers that adsorb at the oil-water interface to form and stabilise emulsions. This study aims to understand the effect of different milk protein compositions (ratio of sodium caseinate and whey protein concentrate (WPC)) with glycerol monooleate (GMO) on physicochemical properties, creaming and oxidative stability of the emulsions. Model emulsions with five different protein compositions were prepared by microfluidisation. The physicochemical properties were characterised by droplet size, zeta potential, viscosity and creaming index. Oxidative stability was assessed using volatile lipid oxidation compounds during ageing (28?ª+days at 45?ª+ degrees C). Results showed that the emulsion with only sodium caseinate produced smaller droplets (174.7?ª+nm), higher zeta potential (-50.8?ª+mV) and a more viscous emulsion (1.89?ª+mPa?ª+s) compared to the emulsion with only WPC (191.4?ª+nm; -38.8?ª+mV; 1.65?ª+mPa?ª+s). Protein composition had no significant effect on creaming stability. Eleven volatile compounds were identified as lipid oxidation markers and six compounds (2-pentylfuran, octanal, nonanal, 3-octen-2-one, 2,4-heptadienal, 3,5-octadien-2-one isomers) demonstrated that emulsions with mixed protein types (sodium caseinate and WPC) had better oxidative stability than emulsions with a single protein type. Therefore, mixed proteins with GMO form stable emulsions with both good physicochemical properties and oxidative stability" |
| Keywords: | Aldehydes Beverages *Caseins Dairy Products Emulsifying Agents/*analysis Emulsions/*analysis Humans Lipid Peroxidation Milk Proteins Oils Oxidation-Reduction Particle Size Viscosity Volatile Organic Compounds/*analysis Water *Whey Proteins Droplet size Em; |
| Notes: | "MedlineLoi, Chia Chun Eyres, Graham T Birch, E John eng Research Support, Non-U.S. Gov't Canada 2019/04/20 Food Res Int. 2019 Jun; 120:83-91. doi: 10.1016/j.foodres.2019.02.026. Epub 2019 Feb 16" |
