The potential correlations between cell-free extracts from Rhodobacter sphaeroides grown under low-oxygen conditions and volatile organic compounds in Chinese-style sausage

Limited research has explored the use of <i>Rhodobacter sphaeroides</i> cell-free extracts (RCFE) in meat processing. To examine the potential application of RCFE in improving the flavor quality of Chinese-style sausage, in this study, we investigated the effects and mechanisms of RCFE grown under low-oxygen conditions on the flavor development of Chinese-style sausage, using GC-MS and 4D label-free proteomics. The GC-MS analysis detected 60 volatile organic compounds, with significant increases in acids, esters, and alcohols following the addition of RCFE (<i>p</i> < 0.01). Fifteen differential flavor compounds were identified as potential biomarkers to distinguish sausages. From a total of 2689 proteins, 364 differentially expressed proteins were identified (<i>p</i> < 0.05, |Log₂FC| > 1, and VIP > 1,) in RCFE grown under low- and high-oxygen conditions. KEGG pathway analysis suggested that the RCFE grown under low-oxygen conditions may enhance alcohol and acid levels by upregulating the expression of related enzymes, which subsequently increases ester levels in the sausage.