Flavonols

Targeted analysis for the detection of phenolics and authentication of Albanian wines using LC-DAD/ESI–MS/MS combined with chemometric tools

“…The bound flavonol glycosides identified in the studied Albanian wines were quercetin-3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-O-glucuronide, and isorhamnetin-3-O-glucoside. The bound quercetin amounts fall in the range of published data for red wines [ 40 , 51 ]. Shib white wine revealed the highest levels of total flavonols (11.82 ± 8.98 mg/L).…”

“…Gallic acid was found in up to 47.4 % of the total phenolic compounds from both regions and vintage, comprising the most abundant phenolic compound. Gallic acid (GA) is a hydrolysis product of condensed and hydrolyzable tannins, chemically classified as gallate esters [ 40 ]. A significant difference in the Kallmet wines was found in GA (LOD-LOQ: 1.89–6.30 μg/mL, R 2 : 0.995), mean values among Lezha (258.05 ± 14.78 mg/L) and Mirdita (190.05 ± 17.67 mg/L) vine zones.…”

“…The primary structural component of the group is (E)-3-phenyl prop-2-enoic acid, more commonly known as cinnamic acid. According to Waterhouse, Sacks, and Jeffery (2016) [ 40 ], tartaric acid esters of caffeic, coumaric, and ferulic acids are mainly extracted from grape berries. In the analyzed wines phenolic acids were found as the second group.…”

“…Flavonols are UV sunscreen compounds and the most diverse nonpolymeric flavonoids isolated in berry skin and wines [ 13 , 40 ]. Their main glycosylated forms in wines are 3-O-glucosides and 3-O-glucuronides.…”

“…The only aglycon flavonol identified was quercetin. The highest quercetin level (2.49 ± 0.02 mg/L) was found in Shib white wines from Tirana county; the interval range in the white wines varied from 0.0 to 2.05 mg/L, while the quercetin levels in both red wines, Kallmet and Shiz, were found in lower level than the interval range of red wines, 3.49–37.36 mg/L [ 40 ]. Meanwhile, flavonol glycosides, quercetin-3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-O-glucuronide, and isorhamnetin-3-O-glucoside in Shib white wines, show levels fall in the interval proposed in white wines.…”