Cinétique d’acidification et activité protéolytique d’un Lactobacillus brevis et application fromagère

Abstract

In cheese technology, milk coagulation is an essential step in which the use of a fermenter can be selected strains or a mixture of strains which do not all have the same performance and technology property, which leads to a great variation in the quality of the cheese. The present work aims to highlight the technological abilities of a strain of lactic acid bacteria indigenous to our local dairy products "Lactobacillus brevis". The strain was revived and controlled by a phenotypic re-characterization through the determination of physiological morphological characteristics. The study focused on the monitoring of acidifying power, lactic acid production, lactic coagulation with its technological times, determination of cheese yield in % and cheese yield in total dry extract. The Lactobacillus brevis strain performed well with a good acidifying power (acidity evolution from 21°D to 102°D) and a cheesability with an excellent proteolytic profile (proteolytic activity at 1, 2 and 3%). By its performances, this strain reveals good technological aptitudes on the cheese application level and on the criteria of cheesability, lactic coagulation, cheese yield and yield in total dry extract. This technological characterization leads us to conclude that this strain could be used in cheese application either in single or mixed culture and with an opportunity of use in a cheese making technology of lactic type or mixed enzymatic type with lactic dominance. Key words: Technological aptitude, Lactobacillus brevis, Lactic coagulation, Cheeseability