Sesame oil is one of the most popular sesame products for consumers. Roasting is a commonly employed heat treatment method in sesame oil processing. This work aims to investigate the effects of roasting temperature and time on sensory profiles, volatile components, fatty acid composition, and oxidative stability of the oil. Quantitative descriptive sensory analysis was employed to reveal changes in aroma characteristics of sesame oils from different roasting conditions. Volatile compounds of the oils were analyzed via headspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS), identifying 56 components, including 30 key aroma-active compounds (odor activity value, OAV ≥ 1) across 18 samples. Principal component analysis (PCA) was performed to explore the effect of roasting conditions on volatiles of sesame oils. The oxidative stability of the oils was also determined by RapidOxy reactor. The results demonstrated that the effect of roasting time on the flavor of sesame oil was greater than that of temperature. Moreover, the effect of roasting conditions (temperature/time) on the fatty acid profile of sesame oil was not significant. This provided some theoretical foundation and data support for improving the processing technology of sesame oil and controlling its flavor quality.

The brewing process is a crucial step in determining the flavor profile of green tea infusions. However, the flavor differences arising from top-brewing and bottom-brewing methods remain poorly understood, and the underlying mechanisms are largely unexplored. In this study, GC-MS and sensory analysis were employed to investigate the flavor differences in Shucheng Little Cymbidium tea infusions under varying water temperatures and brewing methods. Subsequently, the variations in major polyphenolic compounds were analyzed, and the potential causes of flavor differences were explained from the perspective of the interactions between EGCG and key aroma compounds. Multivariate statistical analysis revealed that compounds such as geraniol, nonanal, and methyl salicylate serve as important markers for discriminating between different brewing conditions. Moreover, EGCG exhibited a significant binding effect with compounds such as geraniol and nonanal, driven by hydrogen bonding and hydrophobic interactions. This binding may regulate the transfer of aroma compounds from tea leaves to the infusion during brewing, thereby shaping distinct sensory characteristics. These findings provide a molecular-level rationale for empirical techniques in traditional tea art. More importantly, it inspires researchers to pay attention to the crucial role of the tea infusion matrix in determining flavor.