Mixed Microbial Fermentation-Induced Quality Upgrade of Rapeseed Meal: Volatile Metabolite and Differential Protein...

Area of Science:

• Agricultural Science
• Food Science
• Biotechnology

Background:

• Rapeseed meal (RSM) is a valuable agricultural byproduct with limited use due to high anti-nutritional factors, primarily glucosinolates.
• Microbial fermentation offers a promising strategy to mitigate these anti-nutritional factors and enhance the nutritional and sensory properties of RSM.

Purpose of the Study:

• To investigate the flavor evolution and protein dynamics during the microbial fermentation of RSM.
• To identify key volatile metabolites and differentially expressed proteins (DEPs) associated with flavor changes.
• To establish a theoretical foundation for the high-value utilization of RSM.

Main Methods:

• Physicochemical analyses were conducted to assess changes in RSM composition.
• Volatile metabolomics, including HS-SPME-GC-MS and electronic nose analysis, were employed to profile volatile compounds.
• Quantitative proteomics was utilized to analyze protein expression changes during fermentation.

Main Results:

• Optimal fermentation quality for RSM was achieved at 40 hours, characterized by increased soluble protein and peptides and decreased glucosinolates.
• Dominant volatile compounds identified include esters, terpenoids, and ketones, with 3(2H)-furanone and Benzenemethanethiol identified as key differential metabolites.
• Proteomic analysis revealed 51 DEPs primarily involved in organonitrogen compound, peptide, and protein metabolism, showing significant correlations with 13 differentially accumulated volatile metabolites.

Conclusions:

• Microbial fermentation significantly improves the quality of RSM by altering its protein profile and volatile compound composition.
• The identified DEPs and volatile metabolites provide insights into the biochemical pathways driving flavor development in fermented RSM.
• These findings support the valorization of RSM into functional ingredients for food products like condiments and bakery items.