Analysis of the correlation between dipeptides and taste differences among soy sauces by using metabolomics-based...

Area of Science:

• Food Chemistry
• Sensory Science
• Analytical Chemistry

Background:

• Soy sauce quality is linked to its components, but the relationship between taste and specific dipeptides remains unclear.
• Previous research identified some taste-active dipeptides, yet a comprehensive understanding of their impact on soy sauce flavor profiles is lacking.

Purpose of the Study:

• To investigate the correlations between dipeptides and the taste differences in soy sauces.
• To establish a quantitative link between specific molecular components and sensory attributes of soy sauce.

Main Methods:

• Developed a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method to detect 237 dipeptides in soy sauce.
• Utilized gas chromatography/mass spectrometry (GC/MS) for other low-molecular-weight hydrophilic components.
• Applied orthogonal projections to latent structures regressions (OPLS) to correlate component data with sensory analysis (quantitative descriptive analysis).

Main Results:

• The combined LC/MS/MS and GC/MS data improved model accuracy for sweetness and saltiness compared to GC/MS alone.
• Numerous dipeptides demonstrated a high correlation with taste differences, as indicated by variable importance in projection (VIP) scores.
• Specific dipeptides like Ile-Gln, Pro-Lys, Ile-Glu, Thr-Phe, and Leu-Gln were strongly associated with sweet taste differences.

Conclusions:

• This research provides the first comprehensive report linking specific dipeptides to taste variations in soy sauce.
• The findings offer a scientific basis for evaluating and enhancing soy sauce flavor through targeted dipeptide analysis.
• The developed analytical approach enables precise characterization of soy sauce's sensory properties based on its molecular composition.