Enhancement of Nutritional Value and Sensory Characteristics of Quinoa Fermented Milk via Fermentation with Specific Lactic Acid Bacteria

Quinoa has garnered significant attention for its richness in a variety of nutritional and functional components. Herein, quinoa was fermented with individual or a combination of various lactic acid bacteria (LAB) strains to assess the impact of fermentation on nutrients, functional components, and digestibility. The results indicate that specific LAB fermentation significantly decreased the starch and dietary fiber content while markedly increasing the content and antioxidant capacity of free phenolics. The highest content of free phenolics in fermented quinoa reached 5.64 mg GAE/g, with a 2.01-fold increase in bioavailability. A comprehensive PCA evaluation identified the <i>MS2</i> mixed strain (a 1:1:1 mixture of <i>L. casei89</i>, <i>L. fermentum61</i>, and <i>L. rhamnosus05</i>) as a superior quinoa fermentation agent. Quinoa fermented milk prepared with <i>MS2</i> exhibited favorable taste and aroma properties. After 21 days of storage, the viable bacteria count remained above 10 log CFU/mL, and both the water-holding capacity and suspension stability were still strong. This study provides practical evidence for developing quinoa into a functional food.