de Souza Geany Targino, de Carvalho Rayssa Julliane, de Sousa Jossana Pereira, Tavares Josean Fechine, Schaffner Donald, de Souza Evandro Leite, Magnani Marciane
Laboratory of Microbial Processes in Foods, Department of Food Engineering, Technology Center, Federal University of Paráıba, João Pessoa, 58051900, Brazil.
Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paráıba, João Pessoa, 58051900, Brazil.
J Food Prot. 2016 Feb;79(2):246-52. doi: 10.4315/0362-028X.JFP-15-172.
This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product.
本研究评估了牛至精油（OVEO）对巴西煤霍奶酪体系中的金黄色葡萄球菌、单核细胞增生李斯特菌以及由乳酸菌（乳酸乳球菌乳酸亚种和乳酸乳球菌乳脂亚种）组成的嗜温发酵剂共培养物的抑制作用。OVEO对金黄色葡萄球菌和单核细胞增生李斯特菌的最低抑菌浓度（MIC）均为2.5 μl/ml，对受试发酵剂共培养物的MIC为0.6 μl/ml。在含有0.6 μl/ml OVEO的奶酪肉汤中，未观察到两种病原菌的活菌数（VCC）下降，而在10°C下暴露24小时后，发酵剂共培养物的初始VCC下降了约1.0 log CFU/ml。在奶酪肉汤中暴露24小时后，1.25和2.5 μl/ml的OVEO分别使金黄色葡萄球菌和单核细胞增生李斯特菌的数量减少了高达2.0和2.5 log CFU/ml。在相同浓度下，暴露4小时后，OVEO使发酵剂共培养物的初始VCC下降幅度更大。与奶酪肉汤相比，在半固体煤霍奶酪浆料中降低所有目标细菌的VCC需要更高浓度的OVEO。在相同条件下，含有OVEO的煤霍奶酪浆料中乳酸乳球菌属的VCC始终低于病原菌。这些结果表明，由于OVEO对产品生产过程中使用的发酵乳酸培养物的生长有抑制作用，因此在半硬质奶酪中用于控制病原菌的OVEO浓度应仔细评估。
