Costa Taynan Jonatha Neves, Costa Isabella Maciel, Rocha Wendy Carla Dantas, Campos Maria Eduarda Costa, Oliveira Brenda Costa, Santos Thais Emanuelle Silva, Sartori Diego, Ferreira Andrezza Angélica, Fante Camila Argenta, de Alvarenga Érika Ramos, de Souza Marcelo Resende, Rossi Gabriel Augusto Marques, Salotti-Souza Bruna Maria
Department of Food, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
Department of Technology and Inspection of Animal Products, Veterinary School, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, Brazil.
Braz J Microbiol. 2025 Sep;56(3):1669-1679. doi: 10.1007/s42770-025-01709-7. Epub 2025 Jun 13.
This study aimed to evaluate the effect of lactose and glucose on the viability of lactic acid bacteria (LAB) and assess the microbiological and technological characteristics of lactose-free milk fermented with the potentially probiotic strain Lactococcus lactis GV103. The viability of GV103, either alone or co-cultured with Streptococcus thermophilus STI-12, was evaluated in glucose (Glu), lactose (Lac), and glucose:lactose (Glu:Lac) media. After fermentation, pH, titratable acidity, syneresis, water-holding capacity (WHC), and LAB counts were monitored throughout 28 days of re-frigerated storage. Simulated gastrointestinal tract (GIT) conditions were also assessed for both LAB. When co-cultured, the Lac and Glu:Lac media reached pH 4.6 in approximately 480 min, while Glu required 703.5 min. As a monoculture, GV103 showed the highest counts in Glu:Lac, exceeding 10.50 log CFU/mL. After 28 days, the lactose-free fermented milk had a pH of 3.84 and a titratable acidity of 1.10 g lactic acid/100 mL. Syneresis and WHC were 42.32% and 34.62%, respectively. LAB viability remained above 10.50 log CFU/mL after storage, and both strains survived simulated GIT conditions with counts exceeding 9.00 log CFU/mL. The GV103 and STI-12 proved to be effective, supporting its potential for future probiotic applications in lactose-free dairy products, with attention to fermentation time. The results of this study are promising regarding the use of this microorganism to produce lactose-free fermented milk. However, further studies involving sensory analysis are recommended to assess consumer acceptance, as well as large-scale production to evaluate industrial feasibility.
本研究旨在评估乳糖和葡萄糖对乳酸菌（LAB）活力的影响，并评估用潜在益生菌乳酸乳球菌GV103发酵的无乳糖牛奶的微生物学和工艺特性。在葡萄糖（Glu）、乳糖（Lac）和葡萄糖：乳糖（Glu:Lac）培养基中评估了GV103单独培养或与嗜热链球菌STI-12共培养时的活力。发酵后，在冷藏储存的28天内监测pH值、可滴定酸度、脱水收缩、持水能力（WHC）和LAB计数。还评估了两种LAB在模拟胃肠道（GIT）条件下的情况。共培养时，Lac和Glu:Lac培养基在约480分钟内达到pH 4.6，而Glu需要703.5分钟。作为单一培养物，GV103在Glu:Lac中的计数最高，超过10.50 log CFU/mL。28天后，无乳糖发酵乳的pH值为3.84，可滴定酸度为1.10 g乳酸/100 mL。脱水收缩率和WHC分别为42.32%和34.62%。储存后LAB活力保持在10.50 log CFU/mL以上，两种菌株在模拟GIT条件下均存活，计数超过9.00 log CFU/mL。GV103和STI-12被证明是有效的，这支持了其在无乳糖乳制品中未来益生菌应用的潜力，同时要注意发酵时间。这项研究的结果对于使用这种微生物生产无乳糖发酵乳很有前景。然而，建议进一步开展涉及感官分析的研究以评估消费者接受度，以及开展大规模生产以评估工业可行性。
