Department of Food Science & Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore.
Department of Food Science & Technology, National University of Singapore, Science Drive 2, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, No. 377 Linquan Street, Suzhou Industrial Park, Suzhou 215123, Jiangsu, China.
Int J Food Microbiol. 2021 Jul 16;350:109229. doi: 10.1016/j.ijfoodmicro.2021.109229. Epub 2021 May 4.
Amidst rising demand for non-dairy probiotic foods, and growing interest in coffees with added functionalities, it would be opportune to ferment coffee brews with probiotics. However, challenges exist in maintaining probiotic viability in high-moisture food products. Here, we aimed to enhance the viability of the probiotic bacteria, Lactobacillus rhamnosus GG, in coffee brews by co-culturing with the probiotic yeast, Saccharomyces cerevisiae var. boulardii CNCM-I745. The yeast significantly enhanced the viability of L. rhamnosus GG, as bacterial populations beyond 7 Log CFU/mL were maintained throughout 14 weeks of storage at 4 and 25 °C. In contrast, the single culture of L. rhamnosus GG suffered viability losses below 6 Log CFU/mL within 10 weeks at 4 °C, and 3 weeks at 25 °C. Growth and survival of S. boulardii CNCM-I745 remained unaffected by the presence of L. rhamnosus GG. Volatile profiles of coffee brews were altered by probiotic metabolic activities, but co-culturing led to suppressed generation of diacetyl and ethanol compared to single cultures. Probiotic fermentation did not alter principal coffee bioactive compounds and antioxidant capacities; however, declines in peroxyl radical scavenging capacities were observed after ambient storage. Overall, we illustrate that yeasts are effective in enhancing probiotic bacterial viability in coffee brews, which may be useful in developing shelf stable probiotic food products.
在对非乳制品益生菌食品的需求不断增长，以及对添加功能性成分的咖啡日益关注的背景下，将益生菌发酵到咖啡酿造中是适时的。然而，在高水分食品中保持益生菌的活力仍然存在挑战。在这里，我们旨在通过与益生菌酵母酿酒酵母 var. boulardii CNCM-I745 共培养来提高益生菌细菌鼠李糖乳杆菌 GG 在咖啡酿造中的活力。酵母显著提高了鼠李糖乳杆菌 GG 的活力，因为在 4 和 25°C 的储存条件下，细菌数量在 14 周内都保持在 7 对数 CFU/mL 以上。相比之下，在 4°C 下 10 周内，以及在 25°C 下 3 周内，单一培养的鼠李糖乳杆菌 GG 的活菌数损失低于 6 对数 CFU/mL。酿酒酵母 CNCM-I745 的生长和存活不受鼠李糖乳杆菌 GG 的存在影响。益生菌的代谢活动改变了咖啡酿造的挥发性成分，但与单一培养相比，共培养导致二乙酰和乙醇的生成受到抑制。益生菌发酵没有改变咖啡中的主要生物活性化合物和抗氧化能力；然而，在环境储存后，过氧自由基清除能力下降。总的来说，我们表明酵母在提高咖啡酿造中益生菌细菌的活力方面非常有效，这可能有助于开发货架稳定的益生菌食品。
