School of Food Science and Technology and Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of the Ministry of Education, Shihezi University, Shihezi, Xinjiang 832000, P. R. China.
School of Food Science and Technology and Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of the Ministry of Education, Shihezi University, Shihezi, Xinjiang 832000, P. R. China.
J Dairy Sci. 2021 Jun;104(6):6559-6576. doi: 10.3168/jds.2020-19845. Epub 2021 Mar 6.
Kazakh cheese is a traditional dairy product in Xinjiang, China. To study the function and potential probiotic characteristics of yeast in Kazakh cheese and its contribution to cheese fermentation, we screened the γ-aminobutyric acid (GABA)-producing yeasts Pichia kudriavzevii 1-21, Kluyveromyces marxianus B13-5, Saccharomyces cerevisiae DL6-20, and Kluyveromyces lactis DY1-10. We investigated the potential probiotic properties of these strains and their use in cheese fermentation (cheeses designated CSP, CSM, CSS, and CSI, respectively); a control with no added yeast was designated CS. The results showed that the 4 yeast strains all showed high self-polymerization (2- and 24-h autoaggregation capacity of >80 and 90%, respectively), hydrophobicity (40-92% variation, low hydrophobicity in xylene, but within the range of probiotics), and the ability to survive the gastrointestinal tract (survival rate >75% after simulation), indicating the probiotic ability of the strains in vitro. The GABA production capacity of the CSM cheese increased (to 95.6 mg/100 g), but its protein content did not change significantly, and amino acid degradation was obvious. The GABA production capacity of the CSS cheese decreased (to 450 mg/kg); its protein content declined, and its amino acid content increased. Except for water and protein, we found no obvious differences in most physical and chemical indicators. Kluyveromyces marxianus B13-5 helped to form the desired texture. Multivariate statistical analysis showed that fermentation of the cheese with the 4 yeasts improved the production of esters and alcohols. The CSS cheese had good aroma production performance, because S. cerevisiae DL6-20 produced high concentrations of isoamyl alcohol, hexanoic acid ethyl ester, benzyl alcohol, octanoic acid ethyl ester, 3-hydroxy-2-butanone, and hexanoic acid; the content of 2-methyl-propanoic acid was low. Compared with the CSP cheese, the CSI and CSM cheeses had a fruitier aroma and a milder odor, but the CSI and CSM cheeses had high concentrations of ethyl acetate, butanoic acid, ethyl ester, 3-methyl-1-butanol-acetate, ethyl hexanoate, ethyl octanoate, acetic acid 2-phenylethyl ester, and ethyl lactate; concentrations of 3-methyl-butanoic acid, propanoic acid, acetic acid, and butanoic acid were low. The CSP cheese had stronger acid-producing ability. The order of fragrance production performance was CSS > CSI, CSM > CSP > CS. Research into the fermentation mechanisms of GABA-producing yeast in cheese will provide a theoretical basis for the quality control and industrial production of Kazakh cheese.
中国新疆哈萨克奶酪是一种传统的乳制品。为了研究哈萨克奶酪中酵母的功能和潜在益生菌特性及其对奶酪发酵的贡献，我们筛选了产γ-氨基丁酸（GABA）的酵母毕赤酵母 1-21、马克斯克鲁维酵母 B13-5、酿酒酵母 DL6-20 和德巴利氏酵母 DY1-10。我们研究了这些菌株的潜在益生菌特性及其在奶酪发酵中的应用（分别命名为 CSP、CSM、CSS 和 CSI，无添加酵母的对照命名为 CS）。结果表明，4 株酵母的自聚合能力均较高（2 小时和 24 小时的自动聚集能力均>80%和 90%），疏水性（在二甲苯中的变化为 40-92%，疏水性较低，但在益生菌范围内）和胃肠道生存能力（模拟后存活率>75%），表明菌株在体外具有益生菌能力。CSM 奶酪中的 GABA 产量增加（达到 95.6 mg/100 g），但其蛋白质含量无明显变化，且氨基酸降解明显。CSS 奶酪中的 GABA 产量降低（至 450 mg/kg）；其蛋白质含量下降，氨基酸含量增加。除水和蛋白质外，我们发现大多数物理和化学指标没有明显差异。马克斯克鲁维酵母 B13-5 有助于形成所需的质地。多元统计分析表明，4 株酵母发酵奶酪提高了酯和醇的产量。CSS 奶酪具有良好的香气生产性能，因为酿酒酵母 DL6-20 产生了高浓度的异戊醇、己酸乙酯、苯甲醇、辛酸乙酯、3-羟基-2-丁酮和己酸。2-甲基-丙酸含量较低。与 CSP 奶酪相比，CSI 和 CSM 奶酪具有更浓郁的果香和更温和的气味，但 CSI 和 CSM 奶酪中乙酸乙酯、丁酸、乙酯、3-甲基-1-丁醇-乙酸酯、己酸乙酯、辛酸乙酯、2-苯乙酸乙酯和乳酸乙酯的浓度较高；3-甲基-丁酸、丙酸、乙酸和丁酸的浓度较低。CSP 奶酪具有更强的产酸能力。香气生产性能的顺序为 CSS>CSI、CSM>CSP>CS。研究 GABA 产生酵母在奶酪中的发酵机制将为哈萨克奶酪的质量控制和工业化生产提供理论依据。
