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- Relationship between antioxidant capacity and total phenolic content of red, rosé and white winesPublication . Paixão, Neuza; Perestrelo, Rosa Maria de Sá; Marques, José C.; Câmara, José S.Phenolic compounds are one of the most important quality parameters of wines, since they contribute to wine organoleptic characteristics such as colour, astringency, and bitterness. Furthermore, several studies have pointed out that many show biological properties of interest, related to their antioxidant capacity. This antioxidant activity has been thoroughly studied and a wide variety of methods have been developed to evaluate it. In this study, the antioxidant activity of commercial Terras Madeirenses Portuguese wines (Madeira Island) was measured by three different analytical methods: [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTSradical dot+)) radical cation decolourisation, and ferric reducing/antioxidant power (FRAP) for the evaluation of reducing power (PR) and correlate them with the total phenolic content determined with the Folin–Ciocalteu’s reagent using gallic acid as a standard. The total polyphenol concentration was found to vary from 252 to 1936 mg/l gallic acid equivalents (GAE). The antiradical activity varied from 0.042 to 0.715 mM Trolox equivalents and the antioxidant capacity varied from 344 to 1105 mg/l gallic acid equivalents (GAE). For the reduction power we obtained 3.45–3.86 mM quercetin equivalents.
- Quantification of furanic derivatives in fortified wines by a highly sensitive and ultrafast analytical strategy based on digitally controlled microextraction by packed sorbent combined with ultrahigh pressure liquid chromatographyPublication . Perestrelo, Rosa; Silva, Catarina L.; Câmara, José S.An improved, reliable and powerful analytical strategy based on digitally controlled microextraction by packed sorbent (MEPS) combined with ultrahigh pressure liquid chromatography (UHPLC) was validated for the simultaneous identification and quantification of major furanic derivatives, namely 5-hydroxymethyl-2-furaldehyde (5HMF), 5-methyl-2-furaldehyde (5MF), 2-furaldehyde (2F) and 2-furyl methyl ketone (2FMK), in fortified wines. To enhance the extraction efficiency of the target furanic derivates, several influencing extraction parameters, such as number of loading cycles, nature of elution solvent and elution volume, were evaluated and optimized. In addition the ability of different MEPS sorbent materials, namely C2, C8, C18, SIL, M1, R-AX, R-CX and PGC, were also tested. The optimal analytical conditions involved loading 3×200 μL of wine samples through a C8 sorbent in a MEPS syringe placed in the semi-automatic eVolH syringe followed by elution using 200 μL MeOH:H2O (95:5, v/v). The furanic derivates separation was achieved using a CORTECS UPLC(®) C18 analytical column in an ultrafast chromatographic run (within 4 min). The method performance was assessed for dry/medium dry (D/MD) and sweet/medium sweet (S/MS) model wines in terms of selectivity, linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and matrix effect, using model wine matrix-matched calibration. Good linearity was obtained with a regression coefficient (r(2)) higher than 0.992. A good precision was attained (RSD<5%) and low LODs were achieved for D/MD (4.5-129.3 ng L(-1)) and S/MS (6.9-285.2 ng L(-1)) model wines. The quantification limits (LOQ) for D/MD model wines ranged from 14.9 to 431.0 ng L(-1), whereas for S/MS model wines range from 23.1 to 950.5 ng L(-1). The method also afforded satisfactory results in terms of accuracy, ranging from 74 to 97% for D/MD wines and between 84 and 99% for S/MS wines. The MEPS(C8)/UHPLC-PDA analytical strategy was successfully applied to analyze furanic derivates in 26 fortified Madeira wines from different types (D/MD, S/MS) and ages. The obtained results revealed the analytical strategy as a suitable tool which combines sensitivity, effectiveness, reduced analysis time and simple analytical procedure. Principal component analysis (PCA) suggested that fortified wines can be organized based on their age on PC1, which are mainly characterized by 5HMF.
- Unraveling Vitis vinifera L. grape maturity markers based on integration of terpenic pattern and chemometric methodsPublication . Perestrelo, Rosa; Silva, Catarina; Silva, Pedro; Câmara, José S.The current research attempts to provide an alternative tool for grape maturity measurement related to the wine composition since, the classical parameters (weight grape berries, sugar content, titratable acidity), commonly used in the winemaking industry, do not provide any sensorial information. In this context, the evolution of terpenic compounds (TC) during ripening of four V. vinifera L. grape varieties - Bual, Malvasia, Sercial (white grapes) and Tinta Negra (red grapes), was investigated, in addition to the establishment of terpenic pattern, using headspace solid phase microextraction (HS-SPME) combined with GC–MS. Using the optimal analytical conditions were identified 62 TC in the investigated V. vinifera L. grapes. The integration of chromatographic and chemometric data provides a powerful strategy to identify potential maturity markers. The maximum potential of mono- and sesquiterpenic compounds was reached at maturity, whereas the highest levels of norisoprenoids were observed at véraison. Partial Least Squares Regression (PLS-R) was employed to describe the relationship between classical parameters and TC. Based on PLS-R models, three monoterpenic (linalool, α-terpineol, carvomenthol), one sesquiterpenic (bicyclogermacrene) and two norisoprenoids compounds (vitispirane I, β-damascenone) could be used to define the optimum harvest date. The obtained results represent a very important tool to support, in an objective way, the winemakers decision for long-term strategic planning based on the sensory potentialities of grape varieties and consequently improving the excellence of Madeira wine.
- Comprehensive Evaluation of the Volatomic Fingerprint of Saffron from Campania towards Its Authenticity and QualityPublication . Cozzolino, Rosaria; Stocchero, Matteo; Perestrelo, Rosa; Câmara, José S.The volatile profiles of eight saffron samples (seven cultivated and one spontaneous) grown in different geographical districts within the Campania region (southern Italy) were compared. Using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS SPME/GC-MS), overall, 80 volatiles were identified in the eight landraces. Among them, safranal and its isomers and other related compounds such as isophorones, which are not only key odorants but also pharmacologically active metabolites, have been detected in all the investigated samples. Principal Component Analysis performed on the volatiles’ compounds revealed that the spontaneous sample turned out to be an outlier. In particular, the volatile organic compounds (VOCs) profile of the spontaneous saffron presented four lilac aldehydes and four lilac alcohol isomers, which, to the authors’ knowledge, have never been identified in the volatile signature of this spice. The multivariate statistical analysis allowed the discrimination of the seven cultivate saffron ecotypes in four well-separated clusters according to variety. Moreover, 20 VOCs, able to differentiate the clusters in terms of single volatile metabolite, were discovered. Altogether, these results could contribute to identifying possible volatile signature metabolites (biomarkers) or patterns that discriminate saffron samples grown in Campania region on a molecular basis, encouraging future biodiversity programs to preserve saffron landraces revealing valuable genetic resources.
- Recent Developments in the Applications of Fingerprinting Technology in the Food FieldPublication . Câmara, José S.; Medina, Sonia; Perestrelo, Rosa
- Solid phase microextraction as a reliable alternative to conventional extraction techniques to evaluate the pattern of hydrolytically released components in Vitis vinifera L. grapesPublication . Perestrelo, Rosa Maria de Sá; Caldeira, Michael Manuel Lima; Câmara, José S.In present research, headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC–qMS), was evaluated as a reliable and improved alternative to the commonly used liquid–liquid extraction (LLE) technique for the establishment of the pattern of hydrolytically released components of 7 Vitis vinifera L. grape varieties, commonly used to produce the world-famous Madeira wine. Since there is no data available on their glycosidic fractions, at a first step, two hydrolyse procedures, acid and enzymatic, were carried out using Boal grapes as matrix. Several parameters susceptible of influencing the hydrolytic process were studied. The best results, expressed as GC peak area, number of identified components and reproducibility, were obtained using ProZym M with b-glucosidase activity at 35 °C for 42 h. For the extraction of hydrolytically released components, HS-SPME technique was evaluated as a reliable and improved alternative to the conventional extraction technique, LLE (ethyl acetate). HS-SPME using DVB/CAR/PDMS as coating fiber displayed an extraction capacity two fold higher than LLE (ethyl acetate). The hydrolyzed fraction was mainly characterized by the occurrence of aliphatic and aromatic alcohols, followed by acids, esters, carbonyl compounds, terpenoids, and volatile phenols. Concerning to terpenoids its contribution to the total hydrolyzed fraction is highest for Malvasia Cândida (23%) and Malvasia Roxa (13%), and their presence according previous studies, even at low concentration, is important from a sensorial point of view (can impart floral notes to the wines), due to their low odor threshold (μg/L). According to the obtained data by principal component analysis (PCA), the sensorial properties of Madeira wines produced by Malvasia Cândida and Malvasia Roxa could be improved by hydrolysis procedure, since their hydrolyzed fraction is mainly characterized by terpenoids (e.g. linalool, geraniol) which are responsible for floral notes. Bual and Sercial grapes are characterized by aromatic alcohols (e.g. benzyl alcohol, 2-phenylethyl alcohol), so an improvement in sensorial characteristics (citrus, sweet and floral odors) of the corresponding wines, as result of hydrolytic process, is expected.
- Evaluation of the potencial of Vitis vinifera L. grapes used to produce Madeira wine: impact of winemaking processPublication . Perestrelo, Rosa Maria de Sá; Câmara, José Sousa; Carriço, Sílvia Maria da Rocha Simões
- Geographical differentiation of apple ciders based on volatile fingerprintPublication . Sousa, António; Vareda, José; Pereira, Regina; Silva, Catarina; Câmara, José S.; Perestrelo, RosaWith the globalization of food trade, it’s traceability and genuineness becomes increasingly more difficult. Therefore, it is necessary to develop analytical tools to define the authenticity and genuineness of food-derived products. In the current work, headspace solid-phase microextraction followed by gas chromatography-mass spectrometry (HS-SPME/GC–MS) combined with chemometric tools was used to establish the volatile fingerprint of apple ciders produced in different geographical regions of Madeira Island, in order to define their typicity and to identify putative geographical markers. A total of 143 volatile organic compounds (VOCs) belonging to dif ferent chemical families have been identified, of which 28 were found in all apple ciders independently of geographical region. Esters, terpenic and furanic compounds presented on average a higher contribution for the total volatile fingerprint in cider produced in northern region of the Island, whereas alcohols, acids, volatile phenols, carbonyl compounds and lactones in cider from southern region. Considering the relative areas of the VOCs, 43 revealed statistically significant differences (p < 0.001) between geographical regions, and 11 be tween northern and southern regions. A clear differentiation among cider-producing regions was observed on the developed partial least squares-discriminant analysis (PLS-DA) model. Two alcohols (1-hexanol, 1-octanol), 6 esters (methyl acetate, (Z)-3-hexen-1-ol acetate, ethyl hexanoate, ethyl nonanote, ethyl octanoate, isoamyl oc tanoate) and 1 terpenic compound (limonene), can be considered putative geographic markers due to their discriminatory ability. The results obtained recognize the specific and typical geographical characteristics of the cider, which will allow the forthcoming guarantee for the construction of a sustainable platform for the es tablishment of the authenticity and typicality of the regional cider.
- Evaluation of volatilomic fingerprint from apple fruits to ciders: a useful tool to find putative biomarkers for each apple varietyPublication . Medina, Sónia; Perestrelo, Rosa; Pereira, Regina; Câmara, José S.Aroma is a crucial criterion to assess the quality of apple fruits, juices, and ciders. The aim of this study was to explore similarities and differences in volatile profiles among apple fruits, juices, and ciders from different apple varieties (Festa, Branco, and Domingos) by headspace solid-phase microextraction gas chromatography–mass spectroscopy (HS–SPME/GC–MS). A total of 142 volatile organic compounds (VOCs) were identified, but only 9 were common in all analysed matrices and apple-tested varieties. Esters, alcohols, and aldehydes presented a higher concentration in apple fruits and juices, whereas esters, alcohols, and acids were dominant in ciders. Moreover, there were unique VOCs for each matrix and for each variety, highlighting the importance of the selection of apple varieties as an important factor to obtain good sensory and quality ciders, multiple benefits, and legal protection against the misuse of local products.
- Breast cancer metabolomics: from analytical platforms to multivariate data analysis. A reviewPublication . Silva, Catarina; Perestrelo, Rosa; Silva, Pedro; Tomás, Helena; Câmara, José S.Cancer is a major health issue worldwide for many years and has been increasing significantly. Among the different types of cancer, breast cancer (BC) remains the leading cause of cancer-related deaths in women being a disease caused by a combination of genetic and environmental factors. Nowadays, the available diagnostic tools have aided in the early detection of BC leading to the improvement of survival rates. However, better detection tools for diagnosis and disease monitoring are still required. In this sense, metabolomic NMR, LC-MS and GC-MS-based approaches have gained attention in this field constituting powerful tools for the identification of potential biomarkers in a variety of clinical fields. In this review we will present the current analytical platforms and their applications to identify metabolites with potential for BC biomarkers based on the main advantages and advances in metabolomics research. Additionally, chemometric methods used in metabolomics will be highlighted.