• Carrot has known and appreciated by consumers for their flavors and health attributes. • Terpenes are the predominant volatile flavor substances in fresh carrots. • Heat processing and dehydration affects the characteristic aroma of carrot.

Introduction: This study focused on three kinds of cigar tobacco leaves (Yunxue 6, Yunxue 36, Yunxue 2) produced in Yunnan region, and through the systematic analysis of their physicochemical properties and aroma components of the smoke, the transformation pattern of aroma compounds and their origins during combustion were deeply investigated.Methods: In the experiments, gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS) techniques were used to comprehensively qualitatively and quantitatively analyze the volatile constituents in the tobacco and its smoke, and combined with the conventional chemical composition detection, to reveal the physicochemical properties of Yunnan cigar tobacco and its influence mechanism on the smoke flavor.Results: Yunnan cigar tobacco exhibits distinct chemical characteristics with low sugar (0.12%–0.16%), high nitrogen (2.84%–4.56%) and alkaloid (2.32%–5.56%) contents, along with imbalanced nitrogen-alkali and potassium-chlorine ratios, affecting its combustion and sensory properties. Smoke analysis identified 144 volatile compounds, predominantly heterocyclic, aromatic and olefinic substances, with elevated pyrazines and pyridines contributing roasted, nutty and smoky notes. GC-O-MS analysis revealed 51 key aroma-active components, demonstrating greater complexity in core tobacco (YXYY) than wrapper tobacco (DHYY, PEYY).Discussion: Combustion transforms precursors (carotenoids, cedranes, phenylalanine) into characteristic aromas through pyrolysis and Maillard reactions, enhancing flavor complexity. This study first elucidates the chemical basis of Yunnan cigar’s characteristic aroma, providing theoretical support for quality improvement, process optimization and product differentiation in domestic cigar production. It fills research gaps in Chinese cigar aerochemistry and establishes a foundation for precision cultivation (e.g., chlorine regulation) and targeted fermentation processes to enhance cigar quality.

The Allium plant is widely used in cuisines around the world for its characteristic flavor. The general profile of the plant changes a lot and presents quite different smells after the frying process. In this work, five Allium plants and their fried oils were compared to find out how the frying process impacts the general flavor profile. The results of sensory analysis indicated that the frying process could substantially increase the flavor acceptability of fresh Allium plants. Meanwhile, according to gas chromatography-mass spectrometry (GC-MS) analysis, fewer volatile compounds were detected in fresh Allium plants than in their fried oils. Furthermore, contents of nitrogen-containing compounds (ranging from 0.17 μg/g to 268.97 μg/g), aldehydes (ranging from 71.82 μg/g to 1164.84 μg/g), and lactones (ranging from 0 μg/g to 12.38 μg/g) increased significantly. In addition, more aroma-active substances were identified in the fried Allium oils revealed by gas chromatography-olfactometry (GC-O) analysis. Sulfur-containing compounds were the most abundant in fresh Allium plants, whereas nitrogen-containing compounds dominated in fried oils. The thermal degradation of sugars, amino acids and lipids as well as interactions between carbohydrates, proteins, and fats during the frying process were thought to be the main contributors to these variations. Therefore, this research provides a theoretical basis for the quality control of onion oil flavor and promotes the further development of the onion plant industry. Consequently, the research provided a theoretical basis for the quality control of Allium oils’ flavor and promoted the further development of Allium plant industries.