Impact of different Cynara cardunculus L. extracts on the physicochemical, microbial, and sensory properties of Serpa cheese

Abstract

This study aimed to evaluate the impact of different Cynara cardunculus L. extracts on the physicochemical, microbial, and sensory properties of PDO Serpa cheese, including moisture content, texture, nitrogen fractions, fatty acid profile, microbial characteristics, and overall acceptance. Cheese samples were produced in two dairies (C and G) with three cardoon coagulants (J, C, and G) and analyzed at the beginning of ripening (0 days) and after 30 days. Initially, all samples showed similar moisture, pH, titratable acidity, and trichloroacetic acid-soluble nitrogen (TCA-SN). After ripening, moisture decreased (1.78%–2.82%), with higher levels in cheeses made with cardoon J. Water activity declined more significantly in dairy G’s samples, especially with cardoon J. pH and acidity decreased without notable differences between cardoon types or dairies. Nitrogen fractions stabilized after 30 days, indicating microbial activity as the key driver of proteolysis. Fatty acid analysis revealed palmitic, myristic, oleic, and capric acids as predominant, with dairy G’s samples showing higher monounsaturated fatty acids (MUFA) and lower short-chain fatty acids, like butyric acid. Principal Component Analysis (PCA) highlighted ripening time as the main factor influencing cheese characteristics and, at the end of the ripening process, samples were separated by factory. Microbial analysis showed increased mesophilic and lactic acid bacteria during ripening, while fungi and Enterobacteriaceae counts remained stable. Sensory evaluation indicated higher ratings for dairy G’s cheeses in flavour and acceptance, regardless of cardoon type. This study demonstrates how cardoon type and dairy practices shape cheese quality.