Abstract:
Objective Contents and changes on aromatics in flavor-type grapes in various stages of fruit development were studied.
Method Grapes from Red Globe, Seedless Venus, and Muscat Hamburg varieties were collected for aromatic determination by the headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS).Changes in the contents of major aromatics in 3 growth stages were monitored and analyzed for principal components.
Result Methyl salicylate, dimethyl phthalate, dibutyl phthalate, damascenone, and phenylethyl alcohol were the principal aromatic compounds in the fruits of Seedless Venus; linalool, α-Terpineol, geraniol, and geranic acid flavoring compounds, in those of Muscat Hamburg; and (E)-2-hexenal and 1-hexanol, in those of Red Globe.The content of ester aromatics continued to increase along the process of fruit development; the C13 isoprenoids (e.g., damascenone) were the highest in quantity at young stage; the volatiles, e.g., phenylethanol, accumulated from veraison to maturation; the aromatic terpenoids from young to veraison stage; and the C6 compounds displayed no consistent pattern in the entire growth period.
Conclusion The contents and accumulation of aromatics in the varieties of grapes differed significantly. For instance, the aroma of Seedless Venus grapes came mainly from esters, C13 isoprenoids, and other aromatic compounds, with methyl salicylate, dimethyl phthalate, dibutyl phthalate, damascenone, and phenylethyl alcohol being the major contributors.Whereas Muscat Hamburg grapes composed largely of terpenes including linalool, α-Terpineol, geraniol, and geranic acid, while Red Globe consisted of C6 compounds like (E)-2-hexenal and 1-hexanol.