Comparison of phenolic acids and flavan-3-ols during wine fermentation of grapes with different harvest times.
To explore the effects of harvest time on phenolic compounds during wine fermentation, grape berries (Vitis vinifera L. cv. Vidal) were harvested at 17.5, 22.8 and 37.2 masculine Brix and were used to make dry wine, semi-sweet wine and icewine with low alcohol levels, respectively. Phenolic acids and flavan-3-ols were assayed during the fermentation of wines by means of reverse phase-high performance liquid chromatography (RP-HPLC). The results showed that concentrations of most of the phenolic acids and flavan-3-ol in musts increased with harvest time delay and higher total levels of these species were detected in all wines, compared with those measured before fermentation (the total phenolic acid content in wines was 1.5-2.0 fold that of in musts). Except for p-coumaric acid and (-)-epicatechin, other phenolic acids and flavan-3-ols had similar variation patterns (wave-like rise) during fermentation in dry wine and semi-sweet wine. However, some detected compounds, including gentisic acid, p-hydroxybenzoic acid, caffeic acid, p-coumaric acid and sinapic acid showed obviously different trends from the other two wines in the icewine making process. It is thus suggested that the harvest time has a decisive effect on phenols in final wines and influences the evolution of phenolic acids and flavan-3-ols during wine fermentation.
Tian
Rong-Rong
RR
China Agricultural University, Beijing, P.R. China. rongx2tian@yahoo.com.cn
Pan
Qiu-Hong
QH
Zhan
Ji-Cheng
JC
Li
Jing-Ming
JM
Wan
Si-Bao
SB
Zhang
Qing-Hua
QH
Huang
Wei-Dong
WD
D000383:Agriculture; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D005419:Flavonoids / Q000032:analysis*; D006801:Humans; D062385:Hydroxybenzoates / Q000032:analysis*; D013997:Time Factors; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
D005419:Flavonoids; D062385:Hydroxybenzoates; C404987:flavan-3-ol; C017616:phenolic acid