Impact of Alfalfa Sprouts (Medicago sativa L.) on the Quality of Composite Sourdough Fermented With Lactiplantibacillus plantarum ATCC 8014 and Saccharomyces cerevisiae

Alfalfa sprouts have gained attention due to their nutritional quality and health benefits in finding new nutrient resources to fortify staple food. The sourdough fermentation is a powerful method to exploit its potential in breadmaking. This study aims to assess the performance of wheat-alfalfa sprout composite flours in sourdough fermentation. The impact of Lactiplantibacillus plantarum ATCC 8014 and Saccharomyces cerevisiae in single culture or coculture and alfalfa sprouts addition level on the quality characteristics (biochemical, nutritional, and rheological) of sourdough was tested. Alfalfa sprout flour revealed a high content of protein (38.6%), dietary fibers (33.4%), minerals, and carbohydrates that could contribute to the initiation of sourdough fermentation. At the same time, fatty acids, total polyphenols, and antioxidant activity improve the functional attributes of the product. For sourdough performance, the results show good microbial cell growth (average value of 9 log cfu/g after 24 h) for both tested microorganisms, especially as single cultures, without the negative influence of alfalfa sprout flour on cell viability. Good lactic acid yields (maximum of 5.86 mg/g) and ethanol (maximum of 6.63 mg/g) were produced, indicating good metabolic performance for both inoculants. The upward trend of total free amino acids, ranging from 1.62 to 3.5 mg/mL, was due to the addition of alfalfa sprout flour and the proteolytic activity of the strains. Elevated concentrations of potassium, magnesium, and calcium were identified in all samples, but potassium was slightly higher in yeast fermentation, while magnesium and calcium were in the lactic fermentation. Increasing total polyphenol contents (maximum of 185 mg GAE/100 g) and radical scavenging activity (maximum of 27.36%) were recorded with both alfalfa sprout addition and microbial metabolism. No negative influence of alfalfa sprout flour on sourdough viscoelastic behavior was found. The good quality of wheat-alfalfa sprout sourdough could contribute to the improvement of the final product quality.