trans-Coutaric acid

Volatile, phenolic, and sensory profiles of in-amphorae Chardonnay wine by mass spectrometry and chemometric analysis.[Pubmed:29974572]

J Mass Spectrom. 2018 Sep;53(9):833-841.

The sensory properties, the phenolic composition, and the volatile profile of Chardonnay wine made in amphorae were compared with the wine obtained in large wooden barrels (2000 L) and small toasted barrels (225 L). Hierarchical cluster analysis and principal component analysis built on the phenolics and volatiles variables allowed to group effectively the samples according to the winemaking material used. In-amphorae wines showed more abundant catechin and caffeic acid and less abundant caftaric acid and trans-Coutaric acid. Condensation reactions proceeded in the wood containers leading to esterification of organic acids with ethanol and alcohols, whereas in-amphorae wines were characterized by a higher content of free phenolic acids and higher volatile alcohols. Among the volatile compounds, ramified ethyl esters contributed mostly in samples made in small toasted barrels, whereas nonbranched ethyl esters contributed more for the samples made in large wooden tanks; higher alcohols contributed more for the in-amphorae wine. The sensory analysis showed negligible differences induced by the in-amphorae vinification with respect to the wooden one. Four variables could distinguish wines made in-amphorae compared with the other containers: solvent and acetone (SA), astringent/pungency (AP), fruity (FR), and color intensity (CI). The overall approach proposed here is promising for future developments of innovative types of Chardonnay wine blends.

Kinetics of browning, phenolics, and 5-hydroxymethylfurfural in commercial sparkling wines.[Pubmed:24444020]

J Agric Food Chem. 2014 Feb 5;62(5):1159-66.

We analyzed the degree of browning (absorbance at 420 nm), the phenolics, and the 5-hydroxymethylfurfural (5-HMF) content in six sparkling wines series kept at three temperatures (4, 16, and 20 degrees C) for over 2 years. Caffeic acid, trans-Coutaric acid, p-coumaric acid, and 5-HMF were the compounds with the greatest correlation with browning and time. 5-HMF was the only compound that evolved linearly at all temperatures. We propose that 5-HMF is a better time-temperature marker than the A(4)(2)(0) parameter or phenolics, because it shows higher linearity with time at all temperatures, is more sensitive to temperature changes, and has lower variability. The kinetics of 5-HMF was studied showing a zero-order behavior. We propose mathematical models that wineries can use to predict the browning shelf life of their sparkling wines as a function of the storage time and temperature.

Identification of (poly)phenolic compounds in concord grape juice and their metabolites in human plasma and urine after juice consumption.[Pubmed:21812481]

J Agric Food Chem. 2011 Sep 14;59(17):9512-22.

Analysis of Concord grape juice by HPLC with ESI-MS(n), PDA, and fluorescence detection resulted in the identification and quantification of 60 flavonoids and related phenolic compounds, which were present at an overall concentration of 1508 +/- 31 mumol/L. A total of 25 anthocyanins were detected, which were mono- and di-O-glucosides, O-acetylglucosides, O-p-coumaroyl-O-diglucosides, and O-p-coumaroylglucosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin. The anthocyanins represented 46% of the total phenolic content of the juice (680 mumol/L). Tartaric esters of hydroxycinnamic acids, namely, trans-caftaric and trans-Coutaric acids, and to a lesser extent trans-fertaric acid accounted for 29% of the phenolic content, with a total concentration of 444 mumol/L, of which 85% comprised trans-caftaric acid. Free hydroxycinnamic acids were also quantified but contributed to <1% of the total phenolic content (8.4 mumol/L). The other groups of polyphenolic compounds present in the juice, accounting for 24% of the total, comprised monomeric and oligomeric units of (epi)catechin and (epi)gallocatechin (248 mumol/L), flavonols (76 mumol/L), gallic acid (51 mumol/L), and trans-resveratrol (1.5 mumol/L). The bioavailability of the (poly)phenolic compounds in 350 mL of juice was investigated following acute intake by healthy volunteers. Plasma and urine were collected over 0-24 h and analyzed for parent compounds and metabolites. In total, 41 compounds, principally metabolites, were identified.

Authenticity markers in Aglianico, Uva di Troia, Negroamaro and Primitivo grapes.[Pubmed:20103166]

Anal Chim Acta. 2010 Feb 15;660(1-2):221-6.

Aglianico, Negroamaro, Uva di Troia, and Primitivo, non-aromatic red grapes of southern Italy, were analyzed with respect to berry varietal markers, namely anthocyanins, flavonols, hydroxycinnamoyl tartaric acids (HPLC-DAD) and glycosidic aroma precursors (GC-MS) together with shikimic acid (HPLC-UV). In this study, we confirmed that the relative amount of grape glycosidic precursors from various terpene families was a helpful varietal discriminating factor. An additional decisive contribution to varietal differentiation was also provided by shikimic acid, acetylated forms of anthocyanins, cyanidin-3-O-glucoside, trans-caftaric and trans-Coutaric acids. A three-dimensional model of principal component analysis was adopted to evidence the study results.

Solid foodstuff supplemented with phenolics from grape: antioxidant properties and correlation with phenolic profiles.[Pubmed:17536831]

J Agric Food Chem. 2007 Jun 27;55(13):5147-55.

Osmotic dehydration was assessed as an operation for supplementing a solid foodstuff (a gel was used as the model food) with grape phenolics from a concentrated red grape must to increase its antioxidant properties. The model food was processed for up to 24 h, and the osmotic pressure was adjusted by diluting the concentrated red grape must. In all conditions tested, low molecular weight phenolics (trans-Coutaric acid, ferulic acid, coumaric acid, caffeic acid (hydroxycinnamic acids), gallic acid (hydroxybenzoic acids), quercetin, and rutin (flavonols), were quantified in the red grape must and also in the osmo-dehydrated food. Other flavonoids such as (+)-catechin and (-)epicatechin (flavan-3-ols) were detected only in the red grape must. Trolox equivalent antioxidant activity (TEAC) and ferric reducing antioxidant power (FRAP) were determined in the osmo-dehydrated food. Under the conditions that maximized phenolic infusion, the total phenolic content of the gel was close to the values reported in some rich-in-phenolic fruits and vegetables, whereas TEAC was 3 times that of fresh fruit with the highest antioxidant capacity. Regression analysis showed that the individual phenolics analyzed significantly explain the antioxidant capacity of the osmo-dehydrated food.

In-line pressurized-fluid extraction-solid-phase extraction for determining phenolic compounds in grapes.[Pubmed:12236492]

J Chromatogr A. 2002 Aug 30;968(1-2):1-6.

A new method of pressurized-fluid extraction coupled in-line with solid-phase extraction has been used for the extraction of phenolic compounds from grapes. The full extraction method is performed under an inert atmosphere. Five different solvents have been assayed using different extraction pressures and temperatures. Using two extraction stages with two different solvents, water and methanol, quantitative recovery for most of the assayed compounds has been found in the second extract. Only the most polar phenolic compound, gallic acid, was found distributed in both extracts. The application to real samples allows for a clean-up of the extracts. Cinnamic esters like caftaric acid, cis and trans-Coutaric acids were found only in the methanolic extract. The reproducibility for the new method was measured using both an inert solid spiked with standards and grapes. Using between 202 and 424 microg of spiked standards, the resulting relative standard deviations were less than 5%, with the exception of gallic acid (RSD=13%). For grapes, the resulting RSD were 11% for trans-Coutaric acid, 10% for caftaric acid and 6% for cis-coutaric acid.