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- A powerful methodological approach combining headspace solid phase microextraction, mass spectrometry and multivariate analysis for profiling the volatile metabolomic pattern of beer starting raw materialsPublication . Gonçalves, João L.; Figueira, José A.; Rodrigues, Fátima P.; Ornelas, Laura P.; Branco, Ricardo N.; Silva, Catarina L.; Câmara, José S.The volatile metabolomic patterns from different raw materials commonly used in beer production, namely barley, corn and hop-derived products - such as hop pellets, hop essential oil from Saaz variety and tetra-hydro isomerized hop extract (tetra hop), were established using a suitable analytical procedure based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography-quadrupole mass spectrometry detection (GC-qMS). Some SPME extraction parameters were optimized. The best results, in terms of maximum signal recorded and number of isolated metabolites, were obtained with a 50/30 μm DVB/CAR/PDMS coating fiber at 40 °C for 30 min. A set of 152 volatile metabolites comprising ketones (27), sesquiterpenes (26), monoterpenes (19), aliphatic esters (19), higher alcohols (15), aldehydes (11), furan compounds (11), aliphatic fatty acids (9), aliphatic hydrocarbons (8), sulphur compounds (5) and nitrogen compounds (2) were positively identified. Each raw material showed a specific volatile metabolomic profile. Monoterpenes in hop essential oil and corn, sesquiterpenes in hop pellets, ketones in tetra hop and aldehydes and sulphur compounds in barley were the predominant chemical families in the targeted beer raw materials. β-Myrcene was the most dominant volatile metabolite in hop essential oil, hop pellets and corn samples while, in barley, the predominant volatile metabolites were dimethyl sulphide and 3-methylbutanal and, in tetra hop, 6-methyl-2-pentanone and 4-methyl-2-pentanone. Principal component analysis (PCA) showed natural sample grouping among beer raw materials.
- The salivary volatome in breast cancerPublication . Pereira, Jorge A. M.; Taware, Ravindra; Porto-Figueira, Priscilla; Rapole, Srikanth; Câmara, José S.
- 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.
- Beer volatile fingerprinting at different brewing stepsPublication . Alves, Vera; Gonçalves, João; Figueira, José A.; Ornelas, Laura P.; Branco, Ricardo N.; Câmara, José S.; Pereira, Jorge A. M.Volatile fingerprints of a lager beer were carried out throughout five brewing steps to characterize the changes encompassing this process. Overall, 60 volatile organic metabolites (VOMs) were identified by headspace solid phase microextraction followed by gas chromatography mass spectrometry (HS-SPME/GC–MS). Specific profiles were observed at different brewing steps - aldehydes and furans dominate in wort, whereas the aliphatic esters and alcohols predominate in the following steps. Such variations can be assigned to specific VOMs, as 3-me thylbutanal (wort), ethyl alcohol and ethyl octanoate (fermentation, maturation and filtration), or ethyl alcohol and isoamyl acetate (final product). These VOMs can influence the beer final flavour. Ethyl alcohol contributes to its strong and pungent smell and taste, while isoamyl acetate adds intense ‘fruity’ and ‘banana’ odours. These beer volatile fingerprints constitute a valuable tool to obtain insights on the impact of each brewing step on the final product, being also very useful for certification purposes.
- 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
- Extracellular volatilomic alterations induced by hypoxia in breast cancer cellsPublication . Taware, Ravindra; Taunk, Khushman; Kumar, Totakura V. S.; Pereira, Jorge A. M.; Câmara, José S.; Nagarajaram, H. A.; Kundu, Gopal C.; Rapole, SrikanthIntroduction The metabolic shift induced by hypoxia in cancer cells has not been explored at volatilomic level so far. The volatile organic metabolites (VOMs) constitute an important part of the metabolome and their investigation could provide us crucial aspects of hypoxia driven metabolic reconfguration in cancer cells. Objective To identify the altered volatilomic response induced by hypoxia in metastatic/aggressive breast cancer (BC) cells. Methods BC cells were cultured under normoxic and hypoxic conditions and VOMs were extracted using HS-SPME approach and profled by standard GC–MS system. Univariate and multivariate statistical approaches (p<0.05, Log2 FC≥0.58/≤−0.58, PC1>0.13/<−0.13) were applied to select the VOMs diferentially altered after hypoxic treatment. Metabolic pathway analysis was also carried out in order to identify altered metabolic pathways induced by the hypoxia in the selected BC cells. Results Overall, 20 VOMs were found to be signifcantly altered (p<0.05, PC1>0.13/< −0.13) upon hypoxic exposure to BC cells. Further, cell line specifc volatilomic alterations were extracted by comparative metabolic analysis of aggressive (MDA-MB-231) vs. non-aggressive (MCF-7) cells incubated under hypoxia and normoxia. In this case, 15 and 12 VOMs each were found to be signifcantly altered in aggressive cells when exposed to hypoxic and normoxic condition respectively. Out of these, 9 VOMs were found to be uniquely associated with hypoxia, 6 were specifc to normoxia and 6 were found common to both the conditions. Formic acid was identifed as the most prominent molecule with higher abundance levels in aggressive as compared to non-aggressive cells in both conditions. Furthermore, metabolic pathway analyses revealed that fatty acid biosynthesis and nicotinate and nicotinamide metabolism were signifcantly altered in aggressive as compared to non-aggressive cells in normoxia and hypoxia respectively. Conclusions Higher formate overfow was observed in aggressive cells compared to non-aggressive cells incubated under both the conditions, reinforcing its correlation with aggressive and invasive cancer type. Moreover, under hypoxia, aggres sive cells preferred to be bioenergetically more efcient whereas, under normoxia, fatty acid biosynthesis was favoured when compared to non-aggressive cells.
- Ultrasound-assisted liquid-liquid extraction followed by ultrahigh pressure liquid chromatography for the quantification of major carotenoids in tomatoPublication . Figueira, José A.; Pereira, Jorge A.M.; Porto-Figueira, Priscilla; Câmara, José S.Lycopene and β-carotene, the main carotenoids present in different tomatoes varieties (gordal, cherry, roma and campari) of Solanum lycopersicum L. (Solanaceae), were investigated using ultrasound-assisted liquid-liquid extraction (LLUSAE) followed by ultra-high pressure liquid chromatography with PDA detection (UHPLC-PDA) analysis. Experimental parameters influencing the LLUSAE were optimized using an univariate design, resulting in a 30-min ACN/MeOH extraction by sonication of a lyophilized sample, followed by PSA/C18/MgSO4 clean-up and fast centrifugation before UPLC analysis. Using this greener methodology, high recoveries (above 97%), good linearity (r2 > 0.98) and improved sensitivity, with limits of detection and quantification of 24.0 and 80.0 ng/mL for lycopene and 3.0 and 9.9 ng/mL for β-carotene, respectively, were obtained. This sensitivity is about five times better than previously reported in literature, making LLUSAE/UHPLC-PDA a promising strategy for lycopene and β-carotene quantification in tomato and eventually in other matrices. The carotenoids studied, lycopene and β-carotene, were found at highest concentrations in the gordal tomato variety, followed by cherry, roma and campari (727.1, 342.2, 267.2 and 218.2 μg/g and 80.4, 44.0, 45.7 and 44.0 μg/g for lycopene and β-carotene, respectively). Additionally, an exponential increase of both carotenoids occurs during ripening and mainly in the skin and locular cavity of the gordal variety. These results provide further evidences of the potential of tomatoes as an interesting source of lycopene and β-carotene.