Sensory and Instrumental Consistency of Processed Cheeses

The objective of this study was to evaluate the instrumental and sensory texture of seven cheeses, as well as correlate sensory measurements of texture with mechanical properties. The cheeses were composed of different types of basic mass (casein and whey proteins) and emulsifying salts. Instrumental analysis of texture was performed using the universal mechanical testing machine (Instron) for determining the properties of firmness, elasticity, adhesiveness, gumminess, chewiness and cohesiveness. Data was analyzed using the principal component analysis and clustering analysis. Sensory texture was evaluated by a group of semi-trained assessors according to the ranking-difference test for texture of the products. The results were analyzed by the Friedman test; while sensory and instrumental texture measurements were correlated by the Spearman correlation coefficient. With regard to sensory and instrumental texture of the cheeses, the formation of three groups was observed: a first group consisting of cheeses with intermediate texture, another consisting of softer products and a third group formed of more consistent cheeses. Texture differences of the cheeses were determined by their protein and emulsifying agent composition. Sensory consistency presented a significant correlation (|rs| > 0.90 and p < 0.01) with the properties of mechanical: firmness, adhesiveness, chewiness and elasticity. On the other hand, the sensory texture measurement is not correlated with the instrumental measurements of gumminess and cohesiveness, indicating that they do not reflect the human perception of cheese texture.