Chammas Gisele I, Saliba Rachad, Corrieu Georges, Béal Catherine
INA P-G, INRA, UMR Génie et Microbiologie des Procédés Alimentaires, 78850 Thiverval-Grignon, France.
Int J Food Microbiol. 2006 Jul 1;110(1):52-61. doi: 10.1016/j.ijfoodmicro.2006.01.043. Epub 2006 May 15.
The technological properties of 96 lactic acid bacteria isolated from Lebanese traditional fermented milk "laban" were characterised. They were classified by phenotypic and biochemical analyses as Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, thus indicating that laban is a fermented milk similar to yogurt. Most strains of L. bulgaricus (87.5%) exhibited a high acidification activity, whereas strains of streptococci showed low acidification ability. 33.3% of streptococci strains and 25% of lactobacilli strains displayed similar acidification performances as European strains. Results obtained for syneresis, texture and rheological parameters led us to consider that isolated strains were not low polymer-producing strains. Some of them displayed interesting characteristics such as low syneresis and high values for rheological parameters. The major flavour compounds found in pure cultures were acetaldehyde, acetone, 2-butanone, dimethyl disulfide, acetoin, 2,3-butanedione, 2,3-pentanedione, and acetic, hexanoic and butanoic acids. Acetaldehyde (7.4%) and organic acids (48.3%) were mainly produced by L. bulgaricus strains, whereas streptococci cultures contained high relative levels of 2,3-butanedione and acetoin, which represented around 82% of the total flavour compounds. Finally, strains isolated from laban samples exhibited different technological properties than those used in yogurt production, thus conferring specific characteristics to this product.
对从黎巴嫩传统发酵乳“拉班”中分离出的96株乳酸菌的技术特性进行了表征。通过表型和生化分析，它们被归类为嗜热链球菌和德氏乳杆菌保加利亚亚种，这表明拉班是一种类似于酸奶的发酵乳。大多数保加利亚乳杆菌菌株（87.5%）表现出较高的酸化活性，而链球菌菌株的酸化能力较低。33.3%的链球菌菌株和25%的乳杆菌菌株表现出与欧洲菌株相似的酸化性能。关于脱水收缩、质地和流变学参数的结果使我们认为分离出的菌株不是低聚物产生菌株。其中一些表现出有趣的特性，如低脱水收缩率和较高的流变学参数值。纯培养物中发现的主要风味化合物有乙醛、丙酮、2-丁酮、二甲基二硫、乙偶姻、2,3-丁二酮、2,3-戊二酮以及乙酸、己酸和丁酸。乙醛（7.4%）和有机酸（48.3%）主要由保加利亚乳杆菌菌株产生，而链球菌培养物中2,3-丁二酮和乙偶姻的相对含量较高，约占风味化合物总量的82%。最后，从拉班样品中分离出的菌株表现出与用于酸奶生产的菌株不同的技术特性，从而赋予了该产品特定的特征。
