Abstract
This study investigated the effects of adding Lactobacillus helveticus H11 on the fermentation characteristics, storage performance, and probiotic functionality of brown fermented milk. The results were obtained by analyzing the microrheological properties during the fermentation process, as well as changes in titratable acidity, viable cell count, texture, ACE (angiotensin-converting enzyme) inhibition rate, and metabolite profiles during storage. The findings indicated that the addition of H11 significantly shortened the fermentation time of brown fermented milk and improved its gel structure. Simultaneously, it delayed the post-acidification phenomenon during storage, enhancing storage stability. Moreover, it enhanced the ACE inhibitory activity of the product, demonstrating potential antihypertensive health benefits. Metabolomic analysis further revealed that H11 promoted the production of flavor compounds, such as phenylacetaldehyde and phenyllactic acid, enriching the flavor diversity. Additionally, it concurrently regulated the metabolism of tyrosine and vitamin B6. These discoveries provide a scientific basis for the commercial development of brown probiotic products.