Effect of chemical composition on physico-chemical, rheological and sensory properties of spreadable processed whey cheese

Pasteurised processed cheese spreads of varying chemical composition were developed, using a Myzithra-type cheese, which is a high-moisture and low-fat fresh whey cheese. Nine novel, spreadable processed whey cheese (PWC) samples were prepared comprising only of whey proteins, while guar gum was added as a stabiliser. All samples had a pH value of 5.20, which was obtained with the addition of a starter culture. The effect of chemical composition on the physico-chemical and rheological properties of PWC samples was studied. Due to their texture, two instrumental techniques, lubricated squeezing flow viscometry and texture profile analysis, were considered appropriate for the evaluation of samples. The decrease in protein content or the increase in fat content produced less viscous, consistent and solid samples, which were more spreadable. Protein content was shown to be a better predictor of the texture of PWC samples. Sensory assessments revealed that the majority of PWC samples had good spreadability and flavour and were rated as highly acceptable. Results of sensory and instrumental analyses were highly positively correlated. Results have shown that the choice of the desired formulation could be manipulated for the production of processed whey cheese spreads with specific properties.