Microbiological, rheological and sensory characterization of Portuguese model cheeses manufactured from several milk sources

In attempts to somehow standardize Portuguese traditional cheeses, a better understanding of the physicochemical changes that take place during ripening is mandatory - especially in what pertains to the role played by their main vectors (viz. milk, rennet and microflora). Hence, model cheeses were designed and experimentally manufactured - using three different milk sources, inoculated with well-defined starter cultures - comprising one Lactococcus and one Lactobacillus sp. (or a mixture of both), and coagulated with rennet from either animal or plant origin; such a combination of parameters makes this work a meaningful extension of previous work with related cheese matrices, especially because wild strains were employed. Assessment over a 60 d-period of the gross chemical composition, as well as of microbiological features, rheological properties and sensory textural descriptors allowed one to establish correlations between viscoelastic properties and organoleptic attributes. The importance of pH, fat, protein and water content upon texture evolution, coupled with the effect of animal versus plant rennet upon G′ and G″, and the contribution of Lactococcus lactis to odour development were experimentally elucidated.

► Cheeses were made from 3 milk types, native Lactococcus or Lactobacillus sp., and animal or plant rennet. ► Chemical, microbiological, rheological and sensory profiles were monitored for up to 60 d. ► Correlations were established between viscoelastic properties and organoleptic attributes. ► Effects of rennet source and microbial strain upon G′ and G″ and odour were elucidated.