Mantegazza Giacomo, Dalla Via Alessandro, Licata Armando, Duncan Robin, Gardana Claudio, Gargari Giorgio, Alamprese Cristina, Arioli Stefania, Taverniti Valentina, Karp Matti, Guglielmetti Simone
Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Italy.
Materials Science and Environmental Engineering, Bio and Circular Economy, Tampere University, Finland.
Food Res Int. 2023 Feb;164:112322. doi: 10.1016/j.foodres.2022.112322. Epub 2022 Dec 9.
Fermented foods are receiving growing attention for their health promoting properties. In particular, there is a growing demand for plant-based fermented foods as dairy alternatives. Considering that soy is a vegetal food rich in nutrients and a source of the phytoestrogen isoflavones, the aim of this study was to select safe food microorganisms with the ability to ferment a soy drink resulting in a final product with an increased estrogenic activity and improved functional properties. We used milk kefir grains, a dairy source of microorganisms with proven health-promoting properties, as a starting inoculum for a soymilk. After 14 passages of daily inoculum in fresh soy drink, we isolated four lactic acid bacterial strains: Lactotoccus lactis subsp. lactis K03, Leuconostc pseudomesenteroides K05, Leuconostc mesenteroides K09 and Lentilactobacillus kefiri K10. Isolated strains were proven to be safe for human consumption according to the assessment of their antibiotic resistance profile and comparative genomics. Furthermore, functional characterization of the bacterial strains demonstrated their ability to ferment sugars naturally present in soybeans and produce a creamy texture. In addition, we demonstrated, by means of a yeast-based bioluminescence reporter system, that the two strains belonging to the genus Leuconostoc increased the estrogenic activity of the soybean drink. In conclusion, the proposed application of the bacterial strains characterized in this study meets the growing demand of consumers for health-promoting vegetal food alternatives to dairy products.
发酵食品因其促进健康的特性而受到越来越多的关注。特别是，作为乳制品替代品的植物性发酵食品的需求正在不断增长。鉴于大豆是一种营养丰富的植物性食品，也是植物雌激素异黄酮的来源，本研究的目的是选择安全的食品微生物，使其能够发酵大豆饮料，最终得到具有更高雌激素活性和更好功能特性的产品。我们使用牛奶开菲尔粒（一种具有已证实的促进健康特性的乳制品微生物来源）作为豆浆的起始接种物。在新鲜大豆饮料中每日接种14代后，我们分离出了四株乳酸菌：乳酸乳球菌乳酸亚种K03、类肠膜魏斯氏菌K05、肠膜魏斯氏菌K09和开菲尔扁豆乳杆菌K10。根据对其抗生素抗性谱和比较基因组学的评估，已证明分离出的菌株对人类食用是安全的。此外，对这些细菌菌株的功能特性进行表征表明，它们能够发酵大豆中天然存在的糖分并产生奶油状质地。此外，我们通过基于酵母的生物发光报告系统证明，属于魏斯氏菌属的两株菌株提高了大豆饮料的雌激素活性。总之，本研究中所表征的细菌菌株的拟用应用满足了消费者对促进健康的植物性食品替代乳制品的日益增长的需求。
