Ngamsomchat Achirawit, Kaewkod Thida, Konkit Maytiya, Tragoolpua Yingmanee, Bovonsombut Sakunnee, Chitov Thararat
Division of Microbiology, Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Division of Microbiology, Faculty of Science and Technology, Nakhon-Pathom Rajabhat University, Nakhon-Pathom 73000, Thailand.
Foods. 2022 Mar 24;11(7):934. doi: 10.3390/foods11070934.
Probiotics are increasingly used as functional food ingredients. The objectives of this study were to isolate and characterise probiotic bacteria from dairy and fermented foods and to use a selected strain for the production of probiotic chèvre cheese. Tolerance to acid (pH 2.0) and bile salt (0.4% (w/v)) were first investigated, and then other probiotic properties were determined. Out of 241 isolates, 35 showed high tolerance to acid and bile salt, and 6 were chosen for further characterisation. They were Lactobacillus plantarum and L. fermentum, and possessed antibacterial activities against foodborne pathogens such as Bacillus cereus, Staphylococcus aureus, Salmonella enterica and Escherichia coli O157:H7. L. plantarum (isolate AD73) showed the highest percentage of adhesion (81.74 ± 0.16%) and was nontoxic to Caco-2 cells at a concentration of 108 CFU/mL. This isolate was therefore selected for the production of probiotic chèvre cheese from goat’s milk and was prepared in a lyophilised form with a concentration of probiotic culture of 8.6 log CFU/g. The cheese had a shelf life of 8 days. On the expiry date, the probiotic, the starter and the yeast contents were 7.56 ± 0.05, 7.81 ± 0.03 and 5.64 log CFU/g, respectively. The level of the probiotics in this chèvre cheese was still sufficiently high to warrant its being a probiotic cheese.
益生菌越来越多地被用作功能性食品成分。本研究的目的是从乳制品和发酵食品中分离和鉴定益生菌，并使用选定的菌株生产益生菌山羊奶酪。首先研究了对酸（pH 2.0）和胆盐（0.4%（w/v））的耐受性，然后测定了其他益生菌特性。在241株分离物中，35株对酸和胆盐表现出高耐受性，选择6株进行进一步鉴定。它们是植物乳杆菌和发酵乳杆菌，对蜡样芽孢杆菌、金黄色葡萄球菌、肠炎沙门氏菌和大肠杆菌O157:H7等食源性病原体具有抗菌活性。植物乳杆菌（分离株AD73）表现出最高的黏附率（81.74±0.16%），在浓度为108 CFU/mL时对Caco-2细胞无毒。因此，该分离株被选用于从山羊奶生产益生菌山羊奶酪，并制成冻干形式，益生菌培养物浓度为8.6 log CFU/g。该奶酪的保质期为8天。在保质期结束时，益生菌、发酵剂和酵母含量分别为7.56±0.05、7.81±0.03和5.64 log CFU/g。这种山羊奶酪中的益生菌水平仍然足够高，足以使其成为一种益生菌奶酪。
