Effect of skim milk addition and heat treatment on characteristics of cow milk Ricotta cheese manufactured from Cheddar cheese whey

The effect of varying levels of Cheddar cheese whey to skim milk (70:30, 80:20, 90:10) ratio and heat treatments (95, 90 and 85 degrees C holding for 10, 20 and 30 min each) on the properties of cow milk Ricotta cheese were investigated. The composition, yield, solids recoveries, colour, spreadability and sensory properties were significantly influenced. The composition and solids recoveries increased with increasing skim milk quantity and severity of heat treatment, but higher skim milk had adverse effect on colour, spreadability and sensorial acceptability. The lower proportion of skim milk (90:10) and higher heating temperature (95 degrees C) resulted in Ricotta with high moisture, fat, protein recovery, colour and spreadability and sensory acceptability, as also corroborated by principal component analysis (PCA). PCA extracted five principal components which explained 92.02% variance and grouped cheeses according to the level of cheese milk and heating temperature which are having similar properties. It is possible to produce whiter, uniform, easily spreadable, shiny, soft, creamy, granular, adhesive, and highly acceptable Ricotta from mixing 90 part of Cheddar whey and 10 parts skim milk in cheese milk and heat-treating at 95 degrees C/10 min. In this formulation, whey proteins denaturation and association with casein micelle were validated by RP-HPLC and SDS-PAGE.