• 36 VOCs were identified in two garlic cultivars using HS-SPME-GC-MS. • Sulfur compounds accumulation was promoted by storage at 4°C, but inhibited by storage at 25°C. • Appropriate N fertilization treatment combined with low temperature can synergistically optimize the sulfur metabolism system and maintain the metabolic homeostasis of VOCs. • Diallyl sulfide, diallyl disulphide and tetrasulfide, di-2-propenyl were identified as key VOCs in garlic. As a widely consumed bulb vegetable, garlic aroma is largely determined by volatile organic compounds (VOCs), which are readily affected by cultivar, cultivation practices and postharvest environment. To elucidate the synergistic effects of cultivars, nitrogen fertilization, and storage temperature on allicin and components of VOCs in garlic, two cultivars were grown with four nitrogen levels and stored at two temperatures for 12 weeks. VOC profiles were assayed using HS-SPME-GC-MS, and multivariate statistical analysis was performed to identify key compounds. A total of 36 VOCs were identified, with organosulfur compounds being the predominant VOCs (accounting for 83.3%). Diallyl sulfide, diallyl disulfide, and tetrasulfide, di-2-propenyl were identified as key VOCs. Storage at 4°C enhanced organosulfur compound accumulation, while 25°C caused the key VOC degradation. Nitrogen fertilization and storage temperature significantly influence allicin content, as well as synergistically regulate the sulfur metabolic activity of VOCs. The variation of allicin and VOCs in different cultivars exhibited distinct responses to nitrogen fertilization and storage temperature, suggesting the existence of cultivar-specific regulatory mechanisms.
Qian et al. (Fri,) studied this question.