11 research outputs found
Stability of pelargonidin 3-glucoside in model solutions in the presence and absence of flavanols
The stability of pelargonidin 3-g1ucoside (Pg3g1uc), the main anthocyanin in strawberry, has been studied in model citrate solutions (PH 3.5, 25°C) in the absence and presence flavanols (catechin and procyanidin B3) and/or oxygen. Changes in the solutions were monitorized by HPLC-DAD/MS and UV-visible spectra.Governo Português e Fundo Social Europeu através da medida n.º 5/Acção nº5.3 - PRODEP (III)(referência 5.3/N/199.006/00-Doutoramento)
Anthocyanin composition and related pigments in strawberry
The anthocyanin composition of the strawberry has been object of various studies, but it is still not fully characterized. It is well known the presence af pelarganidin 3 - glucoside (Pg 3 -gluc) as major anthocyanin, usually accompanied of smaller proportions of pelargonidin 3- rutinoside (Pg 3 -rut) and cyanidin 3-glucosid e (Cy. 3- gluc).Comissão Europeia (Fundo Social Europeu) e Governo Português através do Programa PRODEP (III) - ref.ª 5.3/N/199.006/00-Doutoramento
Anthocyanin pigments in strawberry
The anthocyanin composition was analysed in strawberry fruits from five different cultivars (cv. Eris, Oso Grande, Carisma, Tudnew and Camarosa). Twenty-five defined anthocyanin pigments were detected, most of them containing Pelargonidin (Pg) as aglycone; some cyanidin (Cy) derivatives were also found. Glucose and rutinose were the usual substituting sugars, although arabinose and rhamnose were also tentatively identified; some minor anthocyanins showed acylation with aliphatic acids. A relevant aspect was the detection of anthocyanin-derived pigments, namely 5-carboxypyranopelargonidin-3-glucoside and four condensed pigments containing C–C linked
anthocyanin (Pg) and flavanol (catechin and afzelechin) residues. Total anthocyanin content ranged between 200 and 600mg/kg, with
Pg 3-gluc constituting 77–90% of the anthocyanins in the strawberry extracts followed by Pg 3-rut (6–11%) and Cy 3-gluc (3–10%).
A notable variability was found among the anthocyanin concentrations in samples of a same variety and harvest, indicating a strongly influence of the degree of maturity, edaphic-climatic factors and post-harvest storage
Understanding the ellagitannin extraction process from oak wood
[EN] The extractability of the main oak ellagitannins has been studied in five model solutions containing different types of oak chips (two sizes and different toasting degrees for each size). A new extraction kinetic model has been proposed from the quantitative experimental results obtained by means of HPLCeESI-MS/MS-multiple reaction monitoring method. The model considers an initial extraction (i.e., washing step) followed by a diffusion step, which involves two different processes that follow first-order kinetics at different rates. Differences in the extractability of the ellagitannins in the different model solutions have been observed and explained on the basis of the kinetic model here proposed
Flavan-3-ol composition of strawberries
Comissão Europeia (Fundo Social Europeu) e Governo Português através do Programa PRODEP (III) - ref.ª 5.3/N/199.006/00-Doutoramento
Stability of pelargonidin 3-glucoside in model solutions
Comissão Europeia (Fundo Social Europeu) e Governo Português através do Programa PRODEP (III) - ref.ª 5.3/N/199.006/00-Doutoramento
Analysis of anthocyanins in strawberry varieties
Comissão Europeia (Fundo Social Europeu) e Governo Português através do Programa PRODEP (III) - ref.ª 5.3/N/199.006/00-Doutoramento