Survival of Kluyveromyces lactis and Torulaspora delbrueckii to simulated gastrointestinal conditions and their use as single and mixed inoculum for cheese production
Survival of Kluyveromyces lactis and Torulaspora delbrueckii to simulated gastrointestinal conditions and their use as single and mixed inoculum for cheese production
复制标题
DOI：
10.1016/j.foodres.2019.108620
复制
发表时间：
2019-11-01
影响因子：
8.1
通讯作者：
Duarte, Whasley Ferreira
中科院分区：
文献类型：
--
作者：
Andrade, Rafaela Pereira;Oliveira, Daelen Resende;Duarte, Whasley Ferreira
对新益生菌产品的需求最近有所增加，同时对研究奶酪发酵剂的兴趣也越来越大。因此，本研究的目的是评估在模拟胃肠道条件下的生存能力和影响的Torulasporadelbrueckii B14和乳酸克鲁维酵母B10作为单一和混合接种的奶酪生产。将这两种酵母菌株置于模拟胃肠道中，并测试其自聚集、疏水性、病原体抑制、抗生素抗性和β-半乳糖苷酶产生。还评估了酵母菌株在不同NaCl浓度（2.5%、5%和10%w/v）、多种温度（4 ℃和40 ℃）下存活的能力，并将其用作奶酪生产的单一和混合发酵剂。通过YPD平板接种和MALDI-TOF监测酵母菌群水平，并通过HPLC和GC-MS分析21天奶酪成熟过程中的代谢物。T. delbrueckii B14和K.乳酸菌B10在通过模拟胃肠道后均显示出> 80%的存活率，具有> 90%的自聚集率，并且分别显示出0.35U/g和0.53U/g的β-半乳糖苷酶活性。两种酵母在2.5%、5%和10%NaCl下存活21天，并在4 ℃下显示生长。在干酪中，K.乳酸菌B10和混合接种物显示出最高水平的乳糖消耗。对奶酪样品的HS-SPME GC-MS分析可以鉴定出38种挥发性化合物。大多数这些化合物的最高浓度，观察后21天的成熟与混合接种物的奶酪生产。检测到的最丰富的酸是己酸和癸酸;最丰富的醇是2，3-丁二醇、2-苯基乙醇和异戊醇，最普遍的酯化合物是乙酸异戊酯和乙酸苯乙酯。结果表明，T. delbrueckii B14和K.乳酸菌B10是在益生菌背景下进行进一步研究的有趣酵母，并且对奶酪中所需挥发性化合物的组成产生积极影响，特别是当用作混合接种物时。
The demand for new probiotic products has shown recent increases alongside a growing interest in studying starter cultures of cheeses. This study thus aims to evaluate the ability to survive under simulated gastrointestinal conditions and impact of Torulaspora delbrueckii B14 and Kluyveromyces lactis B10 as single and mixed inocula for cheese production. These two yeast strains were subjected to simulated gastrointestinal tracts and tested for self-aggregation, hydrophobicity, pathogen inhibition, antibiotic resistance, and beta-galactosidase production. The yeast strains were also assessed for their ability to survive in different NaCl concentrations (2.5%, 5%, and 10% w/v), multiple temperatures (4 degrees C and 40 degrees C), and used as single and mixed starter cultures for cheese production. Yeasts population levels were monitored by YPD plating and MALDI-TOF and metabolites were analyzed by HPLC and GC-MS over the course of the 21 days cheese maturation process. T. delbrueckii B14 and K. lactis B10 both showed > 80% viability after the passage through the simulated gastrointestinal tract, had self-aggregation rates > 90%, and displayed beta-galactosidase activities of 0.35 U/g and 0.53 U/g, respectively. Both yeasts survived at 2.5%, 5%, and 10% NaCI for 21 days and showed growth at 4 degrees C. In cheese, the single inoculum of K. lactis B10 and mixed inoculum showed the highest levels of lactose consumption. HS-SPME GC-MS analysis of cheese samples allowed the identification of 38 volatile compounds. The highest concentrations of most of these compounds were observed after 21 days of maturation for the cheese produced with mixed inoculum. The most abundant acids detected were hexanoic and decanoic acid; the most abundant alcohols were 2,3-butanediol, 2-phenylethanol and isoamyl alcohol, and the most prevalent ester compounds were isoamyl acetate and phenethyl acetate. Our results therefore show that T. delbrueckii B14 and K. lactis B10 are interesting yeasts for further studies in the context of probiotics and positively impact the composition of desirable volatile compounds in cheeses, particularly when used as mixed inoculum.