Volatile distribution in garlic (Allium sativum L.) by solid phase microextraction (SPME) with different processing conditions

Treatments of autoclaving, high temperature aging (aged-black garlic), crushing, and roasting at 100, 150, and 200°C were applied to alter the volatile profiles of garlic (Allium sativum L.). Headspace volatiles in samples were analyzed by a solid phase microextraction (SPME)- GC/MS. Total peak areas of crushed-raw garlic were the highest and those of aged-black garlic clove were the lowest. Crushing effects were clearly observed in raw garlic, aged-black garlic, and roasted garlic at 200°C for 60 min. Sulfur-containing volatiles including diallyl disulfide and diallyl trisulfide were major volatiles. Generally, peak areas of diallyl disulfide decreased when garlic received autoclaving and roasting treatment while diallyl trisulfide and allyl methyl trisulfide increased during heat treatment compared to raw garlic. Roasting at 200°C for 60 min caused the formation of pyrazines greatly in garlic. Principal component analysis (PCA) for the volatile profiles by SPME-GC/MS could discriminate types of processed garlic successfully.