Four new anthocyanin pigments were found in red wines in trace amounts and are thought to be formed in wines during maturation. Their structures were established by FAB-MS and NMR. Two pigments were identified as the 3-glucoside (vitisin A) and the 3-acetylglucoside (acetylvitisin A) of malvidin containing a C3H2O2 grouping, linking carbon 4 and the 5-hydroxyl group of its molecule (vitisidin A). The other two anthocyanins were identified as the 3-glucoside (vitisin B) and the 3-acetylglucoside (acetylvitisin B) of malvidin containing a CHCH moiety linking carbon 4 and the 5-hydroxyl group of its molecule (vitisidin B or decarboxyvitisidin A). Unlike other anthocyanins these novel compounds were found to be wholly or partly resistant to bleaching by sulfur dioxide and express more color up to pH 7 than malvidin 3-glucoside. Detailed spectral measurements from 250 to 770 nm up to pH 7, including the use of CIELAB 76 measurements, indicate the formation of stable quinonoidal bases, confirming that there could be little formation of the colorless carbinol base forms. Keywords: Red wine; anthocyanins; vitisin A; vitisin B; vitisidin A; vitisidin B; NMR; FABMS

The effect of viscosity and thickener type (sucrose, guar gum, and carboxymethylcellulose) on dynamic flavor release was tested with model flavor solutions at two equiviscous levels. Dynamic flavor release was measured under simulated mouth conditions in an apparatus at 37 °C, with a shear rate of 100 s-1. The volatilized flavors were swept in a flow of helium gas into a mass spectrometer for selected ion monitoring chemical ionization. A plot of time versus ion abundance was recorded for each data set. The highly volatile compounds showed a large decrease in maximum ion abundance (I max) as viscosity increased. Carboxymethylcellulose, guar gum, and sucrose solutions with a viscosity of 160 mPa s showed 36, 44, and 86% decreases compared to water, respectively, for the release of α-pinene. Similarly, 1,8-cineole decreased 32, 40, and 70% and ethyl 2-methylbutyrate decreased 58, 63, and 94%, respectively. The less volatile compounds methyl anthranilate, vanillin, and maltol showed less of an effect. Thickened solutions of similar viscosity did not show the same flavor release, indicating that both viscosity and binding of flavors with the food matrix affect flavor release. Keywords: Viscosity; mass transfer; diffusion; volatility; flavor release; mouth; shear; Stokes−Einstein; thickeners; binding; hydrocolloid

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The effect of different solvents on the extraction of some phenolic compounds from grape seeds was investigated. The main compounds identified by high performance liquid chromatography were gallic acid, (+)‐catechin, (‐)‐epicatechin, the dimeric procyanidins B1 and B2, the trimeric procyanidin C1 and epicatechin gallate. The solvents tested were water, absolute ethanol, 75% ethanol, acetone, 70% acetone, methanol, n‐butanol, diethyl ether, ethyl acetate and a combination of diethyl ether followed by ethyl acetate. Results showed that methanol was the best solvent for the extraction of (+)‐catechin, (‐)‐epicatechin and epigallocatechin, whereas 70% acetone yielded the largest amounts of procyanidins and 75% ethanol yielded the largest amount of gallic acid. The greatest amount of total phenols was extracted by 70% acetone.