Different technical cork stoppers (blend of natural cork microgranules, one-piece natural cork, agglomerated natural cork, technical cork 1+1) were compared to evaluate the effects on the phenolic, volatile profiles and dissolved oxygen in three red (Merlot, Lagrein red, St. Magdalener) and one rosé (Lagrein rosé) wines, which were stored in bottles for 12 months. Gallic acid, caffeic acid, p-coumaric acid, trans-resveratrol, glutahionyl caftaric acid and protocatechuic acid did not vary remarkably during the first three months, whereas at six months a net increase was reported, followed by a clear decrease at 12 months. The same trend was observed in Lagrein rosé, but only for gallic acid. The total anthocyanins content decreased during the storage period in the four wines. Isopentyl acetate, 1-hexanol, ethyl hexanoate, 2-phenylethyl alcohol, diethyl succinate, ethyl octanoate and ethyl decanoate were the main volatile compounds. The sum of alcohols decreased in all four of the wines. The esters decreased in Merlot; however, they increased in Lagrein rosé, Lagrein red and St. Magdalener during the storage. Univariate and multivariate statistics and a sensory discriminant triangle test displayed similar influences of the different stoppers on the phenolic and volatile compounds during the whole storage duration. The changes detected in the phenolic and volatile concentrations were presumably due to the non-oxygen-mediated reactions occurring during 12 months of storage in bottle.
A solid-phase
extraction method was applied for the identification
of a series of unconventional crown (macrocyclic) B-type proanthocyanidin
tetramers (
m
/
z
1169.2557, 1185.2507,
1201.2456, and 1217.2405) and pentamers (
m
/
z
1457.3191, 1473.3140, 1489.3090, 1505.3039, and 1521.2988)
containing (epi)catechins only (procyanidins) or (epi)catechins and
(epi)gallocatechins (prodelphinidins). These compounds were identified
in red wine by high-performance liquid chromatography–high-resolution
mass spectrometry coupled with online hydrogen/deuterium exchange
(HDX) after purification with a C18 solid-phase extraction phase from
the original wine sample. The number and type of monomer units present
in each procyanidin and prodelphinidin are discussed on the basis
of the experimental measured masses, their retention time distribution
among observed isomers, tandem mass spectrometry fragmentations, and
the HDX-induced shift of the theoretical monoisotopic mass. The elution
in reverse-phase high-performance liquid chromatography shifted to
lower retention times when the ratio of (epi)gallocatechin units in
these molecules increased with respect to the content of (epi)catechin
units, as a consequence of the increase of polarity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.