Effect of the addition of liquid whey from cheese making factory on the physicochemical properties of whey protein isolate gels made by high hydrostatic pressure.

The objective of the present work was to study the effect of liquid whey from the cheese production process on the gels developed by high hydrostatic pressure from whey protein isolate powder (WPI). Changes in pH, color, textural parameters, and water retention capacity of the gels obtained were analyzed during storage for 28 days at refrigeration temperature (4 °C). Mixtures of liquid whey from cheese making processes and different WPI percentages gave gels with different characteristics after being processed by high hydrostatic pressures. The pH values and color parameters (L*, a*, b*) varied slightly, depending directly on WPI concentration and storage time. The values of hardness, elasticity, and cohesiveness were dependent on the liquid medium used to dissolve the WPI (liquid cheese whey or distilled water), WPI concentration, and storage time. The use of liquid cheese whey for gel formation favored water retention, reducing the appearance of syneresis (exudation). The results obtained in the present study indicated a possible use and revalorization of cheese whey obtained in cheese production to obtain WPI gels with improved physicochemical properties, using high hydrostatic pressure as technology for their production.