Effect of Wild Strains of Lactococcus lactis on the Volatile Profile and the Sensory Characteristics of Ewes’ Raw Milk Cheese

• Published in: Journal of dairy science Vol. 85; no. 12; pp. 3164 - 3172
• Main Authors: Centeno, J.A., Tomillo, F.J., Fernández-García, E., Gaya, P., Nuñez, M.
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.12.2002; Am Dairy Sci Assoc; American Dairy Science Association
• Subjects: Aminopeptidases - metabolism; Animals; Biological and medical sciences; Cheese - analysis; Cheese - microbiology; Female; Food industries; Fundamental and applied biological sciences. Psychology; Humans; Hydrogen-Ion Concentration; Lactococcus lactis; Lactococcus lactis - metabolism; Milk and cheese industries. Ice creams; raw milk cheese; Sensation; Sheep; Taste; volatile compound; Volatilization; wild strain; Lactococcus lactis; CSC; raw milk cheese; wild strain; volatile compound; BCV; Volatile compound; Organoleptic properties; Dairy product; Sensory analysis; Flavor; Raw milk; Streptococcaceae; Branched chain; Ewe milk cheese; Bacteria; Micrococcales
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(02)74404-4

The production of volatile compounds by wild strains ofLactococcus lactis used as starter cultures and their effect on the sensory characteristics of ewes’ raw milk cheese were investigated. Sixteen vats of cheese were manufactured and ripened for 120 d in two experiments, each of them duplicated. In the first experiment, milk was inoculated with different ratios of four wild Lactococcus lactis strains, two producing and two not producing branched-chain volatile compounds, and in the second experiment with different ratios of a commercial starter culture and the two strains producing branched-chain volatile compounds. Cheese pH, proteolysis, and aminopeptidase activity increased when the strains producing branched-chain volatile compounds were inoculated at a higher rate. Fifty volatile compounds were identified in cheeses using a purge and trap system coupled to a gas chromatography-mass spectrometry apparatus. The relative abundances of 30volatile compounds (8 alcohols, 5 aldehydes, 3 ketones, 12 esters, 1 sulfur compound, and 1 benzenic compound) were influenced by starter culture composition. 2-Methylpropanol, 3-methylbutanol, isobutyl acetate, isoamyl acetate, ethyl butyrate, isobutyl butyrate, and isoamyl butyrate were always more abundant in the cheeses made with a higher level of L. lactis strains producing branched-chain volatile compounds. Flavor intensity was enhanced by a high level of L. lactis strains producing branched-chain volatile compounds in the first experiment, in which four wild L. lactis strains were used as starter culture, but not in the second experiment, in which a combination of two wild L. lactis strains and the commercial starter culture were used. Flavor quality, as judged by trained panelists, was impaired in both experiments by a high level of L. lactis strains producing branched-chain volatile compounds.