engleski

Effects of high pressure on functionality of whey protein concentrate and whey protein isolate

The objective of this study was to evaluate the influence of high-pressure treatments on the solubility, surface hydrophobicity, foaming and emulsifying ability of whey protein concentrate (WPC) and whey protein isolate (WPI). Dispersions of WPC and WPI powders (10% (w/w)) were processed at 300 MPa and 600 MPa, for 5 and 10 min at 40 ± ; ; 2 °C. Changes in protein solubility were determined as solubility at pH 7.0 and at pH 4.6. Assessment of foaming properties was based on the foam expansion during prolonged whipping, and foam stability. Emulsifying properties were characterised by emulsion stability and emulsifying activity indices. The results show significant (P < 0.05) modification of solubility and surface hydrophobicity with increasing intensity and duration of applied pressure, indicating partial denaturation and aggregation of proteins. It was found that high-pressure treatments significantly (P < 0.05) improved the foaming behaviour of WPI, while the foaming ability of WPC was diminished. However, foams formed with high-pressuretreated WPC and WPI exhibited significantly prolonged stability (P < 0.05) compared with control samples. There was a significant trend of decreasing emulsifying efficiency and emulsifying stability related to the intensity of applied pressure and treatment time for both WPC and WPI.

emulsifying properties; foaming properties; high pressure; whey protein concentrate; whey

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