Decoding the aroma of pressed sesame oils: sensory attributes, seed origins and aroma precursors

The aroma profile of pressed sesame oil is systematically influenced by seed origin, blending ratios, and compositional precursors. This study characterized aroma compounds in seven pressed sesame oils (four single-origin; three multi-origin blends). Sensory evaluation revealed universally high intensities of fatty and roasted notes. Instrumental analysis identified 93 aroma compounds, predominantly nitrogen- and sulfur-containing species. Tanzanian white sesame oil (TZ-W-O) contained the highest compound levels; blended oils approximated the dominant raw material origin. Key odorants driving aroma differentiation were 5-ethyl-2,4-dimethylthiazole, 2-acetyl-1,4,5,6-tetrahydropyridine, and 1-octen-3-ol. PCA segregated samples into four clusters, with TZ-W-O forming a unique group due to elevated aldehydes and nitrogenous compounds. Significant origin-based variations occurred in seed amino acids, soluble sugars, and fatty acids. Correlation analysis revealed positive correlations between pyrazines and Lys/Ser levels, while aldehyde formation was positively correlated with oleic acid. These findings establish a foundation for optimizing pressed sesame oil flavor.