Effects of different cooking methods on volatile flavor compounds in garlic

Garlic is an indispensable material in people's daily cooking. It removes fishiness before cooking, seasons during cooking, and adds fragrance after cooking. Garlic is very popular because of its unique taste and aroma. Consequently, the volatile flavor components of garlic after treatment with four cooking methods of steaming, frying, boiling, and roasting were recognized using gas chromatography ion mobility spectrometry (GC–IMS). The relative odor activity value (ROAV) was determined, and the elements were analyzed mainly using principal component analysis (PCA). A total of 73 volatile substances were identified, which were 27 thioethers, 26 aldehydes, 7 ketones, 4 esters, 4 alcohols, 2 furans, and 3 heterocyclic compounds. Those retrieved from fried and roasted garlic carried special properties based on fingerprint analysis and differed notably from steamed and boiled garlic. ROAV analysis of volatiles indicated that steamed garlic contained the highest abundance of flavor components, with two more key compounds, such as 2-methyl-3-(methylthio) furan, and nine more modified flavor compounds, such as octanal, compared to fried garlic. Compared to boiled garlic, steamed garlic contained three important modified-flavor compounds, including 2-pentyl furan, while compared to roasted garlic, there were five important modified-flavor compounds, including 2-pentyl furan.