The characterization of autochthonous cultures based on their contribution to cheese flavor is an additional selection criterion for their use in cheese making. The objective of the present work was to assess the ability of three strains of mesophilic lactobacilli: Lactobacillus casei 72 (Lc72), L. paracasei 90 (Lp90), and L. plantarum 91 (Lp91), one strain of thermophilic lactobacillus: L. helveticus 209 (Lh209), and the thermophilic–mesophilic combinations, to grow and produce aroma compounds in a hard cheese model. Microbiological counts, pH, and the profiles of carbohydrates, organic acids, and volatile compounds were analyzed during incubation for 14 days at 37 ℃. The population of mesophilic lactobacilli reached levels around 8.0 log CFU ml−1 at three days, but then decreased until ∼7.0 log CFU ml−1 toward 14 days. Thermophilic lactobacillus population reached and maintained levels around 7.7 log CFU ml−1 during incubation. Carbohydrates were absent in the hard cheese model, and so no change in the pH values and in the levels of lactic acid was detected. Mesophilic lactobacilli, inoculated individually or in association with Lh209, metabolized the citric acid and produced ethanoic acid. The profiles of volatile compounds of mesophilic lactobacilli (characterized mainly by butan-2-one, 3-hydroxybutan-2-one, 3-methylbutan-1-ol, hexan-1-ol, 2-phenylethanol, and ethanoic acid) were different from the profile of thermophilic lactobacillus Lh209 (characterized mainly by heptan-2-one, ethyl acetate, isoamyl hexanoate, pentan-1-ol, decanoic acid, and 2- and 3-methylbutanal). Cooperative effects in the production of compounds related to cheese flavor, such as 3-hydroxybutan-2-one, ethyl butanoate, ethanol, pentan-2-ol, hexan-1-ol, benzeneacetaldehyde, 2-phenylethanol, and heptanoic acid, were largely evidenced between Lh209 and Lp91; in a lesser extent, cooperative effects were also found for Lh209+Lp90 for the following compounds: 3-hydroxybutan-2-one, isoamyl acetate, and ethanoic acid. Of the mesophilic lactobacilli strains evaluated, Lp91 and Lp90 would be interesting candidates for its use as adjunct cultures in hard cheeses to improve and diversify the flavor.

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评价本土文化以改善奶酪风味：硬奶酪模型的案例研究

基于对奶酪风味的贡献对本土文化的表征是它们在奶酪制作中使用的额外选择标准。本工作的目的是评估三种嗜温乳杆菌菌株的能力：干酪乳杆菌 72 (Lc72)、副干酪乳杆菌 90 (Lp90) 和植物乳杆菌 91 (Lp91)，一种嗜热乳杆菌：L. helveticus 209 (Lh209) 和嗜热-中温组合，在硬奶酪模型中生长和产生香气化合物。在 37 ℃ 培养 14 天期间，分析了微生物计数、pH 值以及碳水化合物、有机酸和挥发性化合物的分布。嗜温乳酸杆菌的数量在 3 天时达到 8.0 log CFU ml-1 左右的水平，但随后在 14 天时下降到 ~7.0 log CFU ml-1。在孵育过程中，嗜热乳酸杆菌种群达到并维持在 7.7 log CFU ml-1 左右的水平。硬奶酪模型中不存在碳水化合物，因此没有检测到 pH 值和乳酸水平的变化。单独接种或与 Lh209 联合接种的嗜温乳酸杆菌代谢柠檬酸并产生乙醇酸。嗜温乳酸杆菌（主要为丁-2-一、3-羟基丁-2-一、3-甲基丁-1-醇、己-1-醇、2-苯基乙醇和乙酸）的挥发性成分分布不同来自嗜热乳酸杆菌 Lh209（主要以庚烷-2-酮、乙酸乙酯、己酸异戊酯、戊-1-醇、癸酸和 2- 和 3-甲基丁醛为特征）的概况。在生产与奶酪风味相关的化合物方面的协同作用，3-羟基丁-2-酮、丁酸乙酯、乙醇、戊-2-醇、己-1-醇、苯乙醛、2-苯基乙醇和庚酸，在Lh209和Lp91之间得到了很大的证实；在较小程度上，还发现了 Lh209+Lp90 对以下化合物的协同作用：3-羟基丁-2-酮、乙酸异戊酯和乙酸。在评估的嗜温乳酸杆菌菌株中，Lp91 和 Lp90 将是有趣的候选者，因为它们用作硬奶酪中的辅助培养物以改善和多样化风味。