Effect of regular and hydrolysed dairy proteins on texture, microstructure and colour of lean poultry meat batters

The use of 2% milk protein isolate (MPI), and some of its fractions which included caseinate, whey protein isolate (WPI), two whey protein hydrolysates (5.2% and 8.5%; WPH-I and WPH-II respectively) and beta-lactoglobulin (beta-lac) was evaluated in lean chicken breast meat batters. Adding caseinate and MPI resulted in the highest fracture force values, and caseinate also provided higher yield compared with the control. Both proteins were observed to form distinct protein islands embedded within the meat protein matrix, which appeared to enhance the gel structure. The two hydrolysates provided the highest yield compared with all other treatments. However, adding WPH-II also resulted in the lowest fracture force and hardness values, while WPH-I provided similar values to the control. The low hardness value could be explained by the light micrograph which showed WPH-II interfering with the binding of the meat proteins. The WPI and beta-lac provided similar yield, fracture and hardness values as the control. The colour of the products was most affected by the WHP-I and WHP-II; both resulted in lower lightness, yellowness and overall spectra reflectance curves. A cost analysis revealed that caseinate addition was the most economical in this lean meat system.