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Polyphenols, antioxidant potential and color of fortified wines during accelerated ageing: the Madeira wine case study

Publication . Pereira, Vanda; Albuquerque, Francisco; Cacho, Juan; Marques, José C.

Polyphenols, antioxidant potential and color of three types of fortified Madeira wines were evaluated during the accelerated ageing, named as estufagem. The traditional estufagem process was set to 45 °C for 3 months. Overheating conditions, 1 month at 70 °C, were also examined. Total polyphenols (TP), total monomeric anthocyanins (TMA) and total flavonoids (TF) were assessed by spectrophotometric methods, while individual polyphenols and furans were simultaneously determined by HPLC-DAD. Antioxidant potential (AP) was estimated by ABTS, DPPH and FRAP assays, while color was evaluated by Glories and CIELab. Traditional estufagem decreased the TP and AP up to 20% and 26%, respectively, with final values similar to other wines. TMA of the Madeira wines from red grapes decreased during estufagem. Six hydroxybenzoic acids, three hydroxycinnamic acids, one stilbene, three flavonols and three flavan-3-ols were found in these wines. The prominent phenolics were hydroxycinnamates and hydroxybenzoates, even after estufagem. Most polyphenols decreased, with the exception of caffeic, ferulic, p-coumaric, gallic and syringic acids. Finally, both chromatic systems revealed that all wines tended to similar chromatic characteristics after estufagem. The study suggests that estufagem can be applied without high impact on polyphenols and antioxidant potential of these fortified wines.

2013Journal article

Open access

Assessment of the development of browning, antioxidant activity and volatile organic compounds in thermally processed sugar model wines

Publication . Pereira, Vanda; Santos, Magda; Cacho, Juan; Marques, José C.

The study evaluates the contribution of the fructose and glucose's degradation for the Madeira wine's features. The browning index, antioxidant activity and volatile organic compounds developed by the glucose and fructose model systems simulating thermally processed sweet Madeira wines were assessed. Sixteen different fructose/glucose model systems were prepared in synthetic wine and stored at 50 C for 4 months. Then, three model wines were also submitted to 70 C for 1 month. The browning index and the antioxidant activity ranged between 0.00 and 0.27 AU and 3.0e65.3 mg(GAE)/L, respectively. The development of several volatile organic compounds was demonstrated (up to 47). The identified com pounds were mostly furans, with 5-hydroxymethylfurfural as the most abundant. For the first time, it was shown that the origin of sotolon in sweet wine can be associated with the acid-catalyzed fructose degradation mechanism. Other 2(5H)-furanones were also identified. It could be concluded that part of the browning, antioxidant activity and aroma compounds developed in sweet fortified wines is associ ated with the thermal degradation of fructose in acid medium.

2017Journal article

Open access

Evolution of 5-hydroxymethylfurfural (HMF) and furfural (F) in fortified wines submitted to overheating conditions

Publication . Pereira, V.; Albuquerque, F. M.; Ferreira, A. C.; Cacho, J.; Marques, J. C.

As furfural (F) and 5-hydroxymethylfurfural (HMF) are essentially formed from sugar dehydration, especially in food submitted to heat, they can be found in beverages, as well as fortified sweet wines. In order to assess the impact of temperature on Madeira winemaking, three traditional varieties of Madeira wines (Malvasia, Sercial and Tinta Negra Mole) were studied to evaluate the F and HMF contents. The wines were produced by two vinification processes, following traditional and modern methodologies, heated at standard conditions (30 °C and 45 °C, for 4 months) and compared with the same wines submitted to overheating conditions (55 °C, for 4 months). The RP-HPLC-DAD methodology used for the control of F and HMF during the process showed no significant changes in the wines maintained at 30 °C (canteiro) and a noticeable but controlled increase in the wines heated at 45 °C (estufagem) where values up to about 150 mg/L of HMF could be found in sweet wines. The strong relation of this compound with the sugar content and baking temperature stood out in the wines submitted to overheating conditions where values higher than 1 g/L could be found for sweeter wines, with HMF level being in general higher than F. The results clearly suggest that the amount of HMF in these fortified wines can be easily controlled when submitted to adequate conditions of heating during estufagem and storage. Furthermore, different temperatures for the baking of sweet and dry wines may be considered.

2011Journal article

Open access

Volatile profile of Madeira wines submitted to traditional accelerated ageing

Publication . Pereira, Vanda; Cacho, Juan; Marques, José C.

The evolution of monovarietal fortified Madeira wines forced-aged by traditional thermal processing (estufagem) were studied in terms of volatiles. SPE extracts were analysed by GC–MS before and after heating at 45 C for 3 months (standard) and at 70 C for 1 month (overheating). One hundred and ninety volatile compounds were identified, 53 of which were only encountered in baked wines. Most chemical families increased after standard heating, especially furans and esters, up to 61 and 3-fold, respectively. On the contrary, alcohols, acetates and fatty acids decreased after heating. Varietal aromas, such as Malvasia’s monoterpenic alcohols were not detected after baking. The accelerated ageing favoured the development of some volatiles previously reported as typical aromas of finest Madeira wines, particularly phenylacetaldeyde, b-damascenone and 5-ethoxymethylfurfural. Additionally, ethyl butyrate, ethyl 2- methylbutyrate, ethyl caproate, ethyl isovalerate, guaiacol, 5-hydroxymethylfurfural and c-decalactone were also found as potential contributors to the global aroma of baked wines.

2014Journal article

Open access

Amino acids and biogenic amines evolution during the estufagem of fortified wines

Publication . Pereira, Vanda; Pereira, Ana C.; Pérez Trujillo, Juan P.; Cacho, Juan; Marques, José C.

The current study was focused on the impact of accelerated ageing (heating step) on the amino acid and biogenic amine profiles of fortified wines. In this sense, three Madeira wines from two commonly used grape varieties (one red and the other white) were analysed during the heating, at standard (45∘ C, 3 months) and overheating (70∘ C, 1 month) conditions, following a precolumn derivatization procedure using iodoacetic acid, o-phthaldialdehyde, and 2-mercaptoethanol, carried out in the injection loop prior to RP-HPLC-FLD detection. Eighteen amino acids were identified, with arginine being the most abundant. An important decrease of the amino acid levels was detected during the standard heating (up to 30%), enhanced up to 61% by the temperature increase. Cysteine, histidine, and asparagine revealed the greatest decreases at 45∘ C. Conversely, some amino acids, such as asparagine, slightly increased. Four biogenic amines were identified but always in trace amounts. Finally, it was observed that the accelerated ageing did not favour the biogenic amine development. The results also indicate that the heating process promotes the amino acid transformation into new ageing products.

2015Journal article

Open access