Year 11 | 10 December 2019 | firstname.lastname@example.org
Some grapevine or some low quality wine have unpleasant green taste. A research data suggest that differences in gas permeability from the different closure and packaging options strongly associate with changes in wine composition during aging
Traces of chemicals called alkyl-methoxypyrazines (MPs) are generally negative to wine quality, masking the desirable fruity and floral flavors and giving wine an unpleasant green taste.
3-Alkyl-2-methoxypyrazines (MPs) represent an important and potent class of grape- and insect-derived odor-active compounds associated with wine quality.
With the wine industry still searching for a way of reducing MP levels, the scientists decided to look at the effects of wine packaging and closures like corks and screw caps.
Thirty nanograms per liter each of 3-isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP), and 3-sec-butyl-2-methoxypyrazine (SBMP) was added to Riesling and Cabernet Franc wines and monitored with headspace solid-phase microextraction and gas chromatography−mass spectrometry over 18 months to investigate the effects of various closure and packaging options on MPs.
Changes in MP concentrations during bottle aging varied with closure/packaging option, with the greatest decrease evident in Tetrapak cartons.
After 18 months, IBMP, IPMP, and SBMP in both Tetrapak-stored wines decreased by approximately 45, 32, and 26%, respectively.
Similar changes were observed in other impact odorants to previous studies, including a greater decrease in odorant concentrations in wines closed with synthetic corks compared to natural corks and screw caps.
These differences are thought to be due to the differential sorptive capacities of the various closure types.
Overall, the data suggest that differences in gas permeability/contribution from the different closure and packaging options strongly associate with changes in wine composition during aging.
Blake et al. Effect of Closure and Packaging Type on 3-Alkyl-2-methoxypyrazines and Other Impact Odorants of Riesling and Cabernet Franc Wines. Journal of Agricultural and Food Chemistry, 2009; 57 (11):
by Graziano Alderighi
06 july 2009, Technical Area > Grapevine & Wine