Screening of Aroma-Producing Performance of Anticlostridial Lacticaseibacillus casei Strains

Abstract

The cheesemaking industry is increasingly interested in using adjunct cultures with potential aromatic and anticlostridial activities. In this study, 34 Lb. paracasei and 2 Lb. rhamnosus strains were isolated from a semi-hard cheese and characterized for their proteolytic, esterase, and anticlostridial activity. Moreover, the strains were inoculated in a curd-based medium and the volatile compounds in the headspace of samples were evaluated by solid-phase microextraction–GC–MS analysis. Proteolytic activity was present in 30 strains, whereas only one Lb. paracasei strain showed esterase activity. All strains inhibited Cl. sporogenes, Cl. beijerinckii, and Cl. butyricum, and 18 isolates inhibited at least one Cl. tyrobutyricum strain. Principal component analysis and clustering analysis based on the volatilome grouped strains into three groups. One of these groups was characterized by high amounts of acids and esters and clustered with control samples inoculated with commercial starter cultures, suggesting similarity in the aroma profile. Strains belonging to this group with inhibitory effects against Cl. tyrobutyricum might be exploited as autochthonous adjunct cultures for the reduction of late-blowing defects in semi-hard cheeses.

The Microbial Community of Natural Whey Starter: Why Is It a Driver for the Production of the Most Famous Italian Long-Ripened Cheeses?

“…Raw milk is a rich and very attractive substrate for different microbial species that use lactose as a carbon source. Environmental factors play crucial roles in shaping the composition of the raw milk microbiota and in defining its evolution in cheese during ripening [1,4,[6][7][8][9][10][11][12][13].…”

“…composition of the raw milk microbiota and in defining its evolution in cheese during ripening [1,4,[6][7][8][9][10][11][12][13].…”