Determining the Behavior of Water in Buttermilk Cheese with Polymerized Whey Protein Using Differential Scanning Calorimetry and Nuclear Magnetic Resonance Analysis

Abstract

In this research, the behavior of water in buttermilk cheese with the addition of polymerized whey proteins was determined. Various parameters of the produced cheese, such as texture, color, water activity, and unbound protein fraction, were examined. Four different samples of buttermilk cheese were prepared, including no addition of whey protein concentrate (BMC); addition of whey protein concentrate (BMC/WPC; 5.62%, w/v), single-heated polymerized whey protein (BMC/SPWP; 28%, w/v), and double-heated polymerized whey protein (BMC/DPWP; 28%, w/v). Differential Scanning Calorimetry (DSC) analysis showed that the highest percentage of freezable water in the water fraction and the lowest of unfreezable water was found in buttermilk cheese with WPC and buttermilk cheese with DPWP. Nuclear magnetic resonance (NMR) analysis showed that the relaxation times were longer in buttermilk cheese with WPC, compared to buttermilk cheese with SPWP and DPWP. Single heat treatment of whey proteins increased stickiness almost 3-fold, and double heat treatment had almost a 2-fold increase in work of shear of cheese samples. The calculated total color difference (ΔE) of the cheese samples suggested that those with polymerized whey protein may increase consumer acceptability.