Exploring the potential application of Bacillus subtilis JLCC513 in the development of cheese whey‐based beverages: A nutritional and aroma perspective

Background Bacillus subtilis can effectively utilise the abundant nutrients present in cheese whey, imparting unique odour characteristics through fermentation. However, no relevant studies have demonstrated the application potential of B. subtilis in whey‐based beverage development. Aim This study aimed to investigate the dynamic changes in nutrient and volatile organic compound (VOC) contents during the fermentation of cheese whey by B. subtilis JLCC513 . The goal was to determine the optimal fermentation time for achieving high nutritional value and a rich aroma profile, thereby evaluating the strain's potential for developing cheese whey‐based beverages. Method Cheese whey was fermented with B. subtilis JLCC513 . Samples were collected at different time points to measure bacterial density, protein, free amino acids, glucose, lactose, organic acids and VOCs. Key analyses included tracking the total free amino acid content and identifying aroma‐active compounds via odour activity value (OAV) calculations. Major Findings Fermentation with B. subtilis JLCC513 preserved lactose while degrading proteins into various free amino acids, with the total free amino acid content peaking at 24 hours of fermentation. The strain primarily enhanced the fruity and grassy aromas of cheese whey by increasing the levels of aldehydes and esters. Analysis of OAV revealed that nonanal, 2‐hexenal, heptanal, dimethyl disulfide, ethyl butyrate, methyl 3‐methylbutanoate, ethyl propanoate, 2‐methylbutanal acetate, ethyl acetate, methyl butanoate, 2,3‐butanedione and hexanal were the main volatile compounds contributing to the aroma profile of the fermented cheese whey. Further investigation into the dynamic changes in VOC concentrations indicated that 48 h of fermentation represented a critical juncture for aroma development in B. subtilis ‐fermented whey, with the most abundant characteristic aroma compounds being present at this time. Scientific or Industrial Implications This study provides a theoretical basis and technical support for the high‐value utilisation of cheese whey and the development of novel fermented beverages.