Effect of Various Ingredients on a Model Process Cheese System

Abstract

The process cheese industry desires to increase formula flexibility by incorporating various alternative ingredients into process cheese. For example, incorporation of whey protein could reduce the amount of casein used in process cheese formulations. The purpose of this study was to understand effects of various ingredients and how they affect texture and meltability of cheese. The ingredients studied were native whey protein, mono- and disodium phosphate, lactose, and polymerized whey protein concentrate (pWPC). Cheese analogs contained mono- and disodium phosphate, lactose, 1 of 4 different whey protein ingredients or pWPC. Cheese analogs were made by heating and mixing for 21 min in a Stephan mixer with endpoint temperatures of 80C or 85C. The pWPC was prepared by heating WPC at 90C, pH 8.0, for 30 min. Properties of pWPC were determined by small strain rheology. Cheese analogs were characterized by yield stress and meltability measurements. Native whey protein showed no clear trend with regard to yield stress or meltability. Also, the addition of lactose at 0% to 4.4% and mono- and disodium phosphate between 2.0% to 2.8% had no effect on yield stress while meltability results showed no consistent trend of cheeses cooked to 80C. Differences were observed when cheese was heated to an endpoint of 85C. The higher temperature increased yield stress approximately 80% and reduced meltability from a Schreiber number of about 9 to 5.

Of four protein concentrations tested for polymerization, 5.0% and 4.5% protein had low viscosity, while 5.5% protein produced a texture similar to jelly. Generally, 6% protein formed a gel. A 13% substitution of casein with native WPC in a cheese analog resulted in a slight decrease in yield stress and no change in meltability. Whereas, a 13% substitution of casein with pWPC in a cheese analog increased the yield stress approximately 18% and decreased meltability from a Schreiber number of about 10 to 8.

Different levels of lactose did not affect the texture or meltability of the process cheese analog, however, the level of mono- and disodium phosphate and whey protein did result in differences in yield stress and meltability. These differences were observed at a much greater extent when the cheese analog was cooked to a final temperature of 85C.