How three adventitious lactic acid bacteria affect proteolysis and organic acid production in model Portuguese cheeses manufactured from several milk sources and two alternative coagulants

• Published in: Journal of dairy science 2010-04, Vol.93 (4), p.1335-1344
• Main Authors: Pereira, C.I., Neto, D.M., Capucho, J.C., Gião, M.S., Gomes, A.M.P., Malcata, F.X.
• Format: Article
• Language: English
• Subjects: Acetic Acid - metabolism; adventitious lactic acid bacteria; Animal productions; Animals; Biological and medical sciences; Cattle; Cheese - microbiology; cheese milk; cheese starters; cheesemaking; cheeses; Citric Acid - metabolism; Coagulants - pharmacology; ewe milk; Fermentation; food analysis; food composition; Food Handling - methods; Food industries; food matrix; Food Microbiology; Fundamental and applied biological sciences. Psychology; goat milk; Goats; Lactic Acid - metabolism; lactic acid bacteria; Lactobacillus; Lactobacillus brevis; Lactobacillus brevis - metabolism; Lactobacillus plantarum; Lactobacillus plantarum - metabolism; Lactococcus; Lactococcus lactis - metabolism; Lactococcus lactis subsp. lactis; Milk; model food systems; organic acids and salts; Plant and animal coagulant; Portugal; proteolysis; rennet; rennet substitutes; Sheep; Sheep milk; Terrestrial animal productions; traditional technology; Vertebrates
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2009-2294

Model cheeses were manufactured according to a full factorial experimental design to help shed light on the individual and combined roles played by 3 native lactic acid bacteria (Lactococcus lactis ssp. lactis, Lactobacillus brevis, and Lactobacillus plantarum) upon proteolysis and organic acid evolution in cheese. The model cheeses were manufactured according to a generally representative Portuguese artisanal protocol, but the (ubiquitous) adventitious microflora in the cheesemaking milk were removed via sterilization before manufacture; therefore, the specific effects of only those lactic acid bacteria selected were monitored. In addition, 2 types of coagulant (animal and plant) and 3 types of cheesemaking milk (cow, sheep, and goat) were assessed to determine their influence on the final characteristics of the model cheeses. The nature of the coagulant appeared to be essential during the first stage of proteolysis as expected, whereas the contribution of those bacteria to the pools of total free AA and organic acids was crucial afterward. This was especially so in terms of the differences observed in the metabolisms of lactic acid (in the case of Lactococcus spp.) as well as acetic and citric acids (in the case of Lactobacillus spp.).