Aroma Formation and Key Volatile Compounds in Coriander Leaves Across Growth Stages Based on GC-MS and E-Nose

This study aimed to systematically investigate the dynamic changes in volatile aroma compounds of coriander (Coriandrum sativum L.) leaves at different growth stages, and identify key aroma-active substances and critical developmental periods for aroma formation, so as to provide a scientific basis for high-quality cultivation, optimal harvest timing, and value-added processing of coriander.

‘Siji Dayouye’ coriander was used as the experimental material. Leaf samples were collected at five growth stages (15, 25, 35, 45, and 55 days after sowing). Volatile compounds were extracted using headspace solid-phase microextraction and analyzed by gas chromatography–mass spectrometry (HS-SPME/GC-MS), and overall aroma profiles were evaluated using an electronic nose (E-Nose) system. Key aroma compounds were identified based on odor activity values (OAV>1). Pearson correlation analysis was applied to explore relationships between volatile compounds and E-Nose sensor responses.

A total of 119 volatile compounds were identified, including aldehydes (38), alcohols (17), hydrocarbons (25), esters (8), acids (10), ketones (8), and other compounds (13). Both the number and total content of volatile compounds increased initially and then declined, reaching a maximum at 35 days, with total volatile content 37.3% higher than that at 15 days. Aldehydes were the predominant compounds, showing a 45.5% increase at 35 days, mainly attributed to trans-2- tetradecenal and trans-2-decenal. E-Nose analysis revealed that sensors W2W, W5S, and W1C exhibited the strongest responses, with significant variations among growth stages. 17 key aroma-active compounds (OAV>1) were identified, 15 of which were aldehydes. Trans-2-tetradecenal showed the highest OAV (175850) at 25 days and was the principal contributor to the characteristic “fresh” and “citrus-like” aroma of coriander. Radar fingerprint analysis demonstrated distinct aroma profiles at different stages: “fresh” notes at 15 days; enhanced “citrus-like” and “oily” aromas at 25-35 days; prominent “fruity” and “camphor-like” notes at 45 days; and a notable “floral” aroma at 55 days. Correlation analysis indicated significant associations between key aldehydes and E-Nose sensor responses.

The combined application of GC-MS and E-Nose effectively characterized aroma variation in coriander leaves across different growth stages, established correlations between sensor responses and volatile compounds, and elucidated the aroma evolution mechanism of coriander leaves.