Showing papers by "Branca M. Silva published in 2007"
TL;DR: Quince leaves total phenolic content was very high, indicating that these leaves can be used as a good and cheap source of bioactive constituents, and significantly differences were observed in 3- O-caffeoylquinic and 3,5- O -dicaffeoyLquinic acids contents, according to geographical provenance and harvesting month, suggesting a possible use of these compounds as geographical origin and/or maturity markers.
Abstract: Cydonia oblonga Miller leaves phenolic compounds were analyzed by reversed-phase HPLC/DAD and HPLC/UV. Qualitative and quantitative analysis of phenolics were carried out in a total of 36 samples of quince leaves from three different geographical origins of Northern (Braganca and Carrazeda de Ansiaes) and Central Portugal (Covilha) and three collection months (June, August, and October of 2006). These leaves presented a common phenolic profile composed by nine compounds: 3- O-, 4- O- and 5- O-caffeoylquinic acids, 3,5- O-dicaffeoylquinic acid, quercetin-3- O-galactoside, quercetin-3- O-rutinoside, kaempferol-3- O-glycoside, kaempferol-3- O-glucoside, and kaempferol-3- O-rutinoside. 5- O-caffeoylquinic acid was the major phenolic compound (36.2%), followed by quercetin 3- O-rutinoside (21.1%). Quince leaves are characterized by higher relative contents of kaempferol derivatives than fruits (pulps, peels, and seeds), especially in what concerns kaempferol-3- O-rutinoside (12.5%). C. oblonga leaves total phenolic content was very high, varying from 4.9 to 16.5 g/kg dry matter (mean value of 10.3 g/kg dry matter), indicating that these leaves can be used as a good and cheap source of bioactive constituents. Significantly differences were observed in 3- O-caffeoylquinic and 3,5- O-dicaffeoylquinic acids contents, according to geographical provenance and harvesting month, suggesting a possible use of these compounds as geographical origin and/or maturity markers.
100 citations
TL;DR: In this paper, a reversed phase HPLC/UV-Vis methodology for determination of twenty free amino acids in Dao red wine was described, and sample preparation was simple, involving only a pre-column derivatization with dabsyl chloride.
Abstract: A reversed‐phase HPLC/UV‐Vis methodology for determination of twenty free amino acids in Dao red wine is described. The sample preparation was simple, involving only a pre‐column derivatization with dabsyl chloride. The HPLC/UV‐Vis procedure is sensitive, reproducible, and accurate. The detection limit values for free amino acids were low, between 0.01 and 0.07 µg/mL, and the method was precise. As a general rule, the recovery values were high. This methodology was applied to the evaluation of the effect of the spoilage wine yeast Dekkera bruxellensis on the Dao red wine free amino acids profile. This yeast seems to influence the free amino acids composition of the wine, including aspartic and glutamic acids, asparagine, glutamine, and isoleucine as the main affected compounds.
9 citations
TL;DR: In this article, a homo-monoterpenic compound (trans-9-amino-8-hydroxy-2,7-dimethylnona -2,4-dienoic acid glucopyranosyl ester) was identified and quantified by HPLC/DAD (diode-array detector) in several pulps, peels and jams.
7 citations
01 Jan 2007
1 citations
01 Jan 2007
TL;DR: In this article, the authors demonstrate the great utility of phenolic profile determination in the evaluation of quince derivatives authenticity, and demonstrate that phenolic profiles can be used to verify quince products.
Abstract: frequently, quince products industry uses other fruits in its manufacture. Pear and apple seem to be the most used for this effect, once they are easily accessible, of low cost and have a similar texture of quince. unpeeled fruits utilization is also very usual in the production of quince jams, although not allowed by Portuguese legislation. in this revision paper, we intend to demonstrate the great utility of phenolic profile determination in the evaluation of quince derivatives authenticity.