Résumé:
The present study focused on the technological aptitudes of two lactic strains, one mesophilic (Lactococcus) and the other thermophilic (Lactobacillus). The strains were revived and phenotypically re-characterized by determining morphological and physiological characteristics. The technological profile involved monitoring their acidifying power, through acidification kinetics and the hydrogen potential developed, as well as their proteolytic activity, a comparative study of the lactic coagulation kinetics of the 02 strains, and a determination of cheese yield in culture alone and in combination. The Lactobacillus strain presumed to be Lactobacillus acidophilus performed best, with a high acidifying power (acidity of 98 °D and a pH of 3.98), compared with the Lactococcus strain presumed to be Lactococcus lactis subsp.
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lactis biovar diacetylactis, with an acidity of 56 °D and a pH of 5.38, which reached the same level. The activity of these strains reveals good cheese-making technological aptitudes. Lactobacillus is a good lactic leavening agent for milk fermentation and lactic coagulation. Lactococcus, with its low acidification kinetics, reveals a highly interesting aromatic profile that can be adapted to either fresh or ripened cheese technology. The mixed culture reveals a good cheese yield with a combination that can be used to produce either lactic or mixed cheese curds.
