Browsing by Author "Perestrelo, Rosa"
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- An approach of the Madeira wine chemistryPublication . Perestrelo, Rosa; Luís, Catarina; Gonçalves, Carolina; Castillo, Mariangie; Câmara, José S.Madeira wine is a fortified Portuguese wine, which has a crucial impact on the Madeira Island economy. The particular properties of Madeira wine result from the unique and specific winemaking and ageing processes that promote the occurrence of chemical reactions among acids, sugars, alcohols, and polyphenols, which are important to the extraordinary quality of the wine. These chemical reactions contribute to the appearance of novel compounds and/or the transformation of others, consequently promoting changes in qualitative and quantitative volatile and non-volatile composition. The current review comprises an overview of Madeira wines related to volatile (e.g., terpenes, norisoprenoids, alcohols, esters, fatty acids) and non-volatile composition (e.g., polyphenols, organic acids, amino acids, biogenic amines, and metals). Moreover, types of aroma compounds, the contribution of volatile organic compounds (VOCs) to the overall Madeira wine aroma, the change of their content during the ageing process, as well as the establishment of the potential ageing markers will also be reviewed. The viability of several analytical methods (e.g., gas chromatography-mass spectrometry (GC-MS), two-dimensional gas chromatography and time-of-flight mass spectrometry (GC×GC-ToFMS)) combined with chemometrics tools (e.g., partial least squares regression (PLS-R), partial least squares discriminant analysis (PLS-DA) was investigated to establish potential ageing markers to guarantee the Madeira wine authenticity. Acetals, furanic compounds, and lactones are the chemical families most commonly related with the ageing process.
- An exploratory study to evaluate the potential of nanohydroxyapatite as a powerful sorbent for efficient extraction of volatile organic metabolites, potential biomarkers of cancerPublication . Qiao, Zheng; Perestrelo, Rosa; Shi, Xiangyang; Rodrigues, João; Câmara, José S.Developing early-stage diagnostic methods which are specific, highly sensitive and non-invasive for cancer has received much attention. In this paper, nanohydroxyapatite (NHA) was for the first time used as a sorbent to extract volatile organic metabolites (VOMs) which are considered as potential biomarkers of cancer, such as hexanal, heptanal, decanal, benzaldehyde, 4-heptanone, phenol, undecane, and 5-methyl-2-furfural. The extraction process was performed by simply dispersing nanohydroxyapatite into working solution containing targeted VOMs and then eluting the centrifuged sorbent with an organic solvent. Batch techniques were performed to optimize the experimental variables affecting the extraction of targeted VOMs such as the sorbent amount, adsorption time, elution time and types of elution solvent. The eluent was collected, concentrated and analyzed by gas chromatography-mass spectrometry (GC-qMS). Under optimized conditions, the results obtained demonstrated a good linearity (r2 ≥ 0.993), over the linear dynamic range, for all urinary volatile metabolites investigated. The proposed strategy provided limits of detection (LODs) ranging from 9.8 ng L−1 to 69.5 ng L−1 and limits of quantification (LOQs) from 32.5 ng L−1 to 231.6 ng L−1. The method also afforded satisfactory results in terms of the matrix effect (72.8–96.1%) and recoveries (accuracy) higher than 70% for most of the studied VOMs. The intra-day and inter-day precision was lower than 3% and 13%, respectively. The established method has been successfully applied to the determination of the target urinary VOMs, from cancer patients, described as potential cancer biomarkers.
- An improved and miniaturized analytical strategy based on μ-QuEChERS for isolation of polyphenols. A powerful approach for quality control of baby foodsPublication . Casado, Natalia; Perestrelo, Rosa; Silva, Catarina L.; Sierra, Isabel; Câmara, José S.An improved and miniaturized quick, easy, cheap, effective, rugged and safe (μ-QuEChERS) strategy combined with ultra-high pressure liquid chromatography coupled to a photodiode array detection system (UHPLC-PDA) was developed and optimized for the determination of twelve polyphenols in different baby foods samples. The proposed analytical approach proved to be highly cost-effective and environmentally friendly, since it showed good extraction efficiency using few amounts of sample (0.3 g), organic solvents (1000 μL), clean-up sorbents (87.5 mg) and partitioning salts (0.2 g), producing minimal waste disposal and reducing analysis time. Method performance was validated in terms of selectivity, linearity, limits of detection and quantification, matrix effects, precision and accuracy using different baby food matrices according to their composition. The overall average recoveries ranged from 71 to 100% with relative standard deviations lower than 6% (n = 18). The method was successfully applied to commercial baby food samples (including pureed solids, juices and porridges), and their total phenolic content (TPC) and antioxidant capacity (RSA) were also investigated. Results allowed characterizing the abundance of the selected polyphenols in the samples, and the highest RSA and TPC were found in the fruit-based baby foods. Thus, this work represents a first approach to determine the nutritional quality of these products.
- An integrative approach based on GC–qMS and NMR metabolomics data as a comprehensive strategy to search potential breast cancer biomarkersPublication . Silva, Catarina Luís; Perestrelo, Rosa; Capelinha, Filipa; Tomás, Helena; Câmara, José S.Introduction Globally, breast cancer (BC) is leading at the top of women's diseases and, as a multifactorial disease, there is the need for the development of new approaches to aid clinicians on monitoring BC treatments. In this sense, metabo lomic studies have become an essential tool allowing the establishment of interdependency among metabolites in biological samples. Objective The combination of nuclear magnetic resonance (NMR) and gas chromatography–quadrupole mass spectrometry (GC–qMS) based metabolomic analyses of urine and breast tissue samples from BC patients and cancer-free individuals was used. Methods Multivariate statistical tools were used in order to obtain a panel of metabolites that could discriminate malignant from healthy status assisting in the diagnostic feld. Urine samples (n=30), cancer tissues (n=30) were collected from BC patients, cancer-free tissues were resected outside the tumor margin from the same donors (n=30) while cancer-free urine samples (n=40) where obtained from healthy subjects and analysed by NMR and GC–qMS methodologies. Results The orthogonal partial least square discriminant analysis model showed a clear separation between BC patients and cancer-free subjects for both classes of samples. Specifcally, for urine samples, the goodness of ft (R2 Y) and predictive ability (Q2 ) was 0.946 and 0.910, respectively, whereas for tissue was 0.888 and 0.813, revealing a good predictable accuracy. The discrimination efciency and accuracy of tissue and urine metabolites was ascertained by receiver operating charac teristic curve analysis that allowed the identifcation of metabolites with high sensitivity and specifcity. The metabolomic pathway analysis identifed several dysregulated pathways in BC, including those related with lactate, valine, aspartate and glutamine metabolism. Additionally, correlations between urine and tissue metabolites were investigated and fve metabo lites (e.g. acetone, 3-hexanone, 4-heptanone, 2-methyl-5-(methylthio)-furan and acetate) were found to be signifcant using a dual platform approach. Conclusion Overall, this study suggests that an improved metabolic profle combining NMR and GC–qMS may be useful to achieve more insights regarding the mechanisms underlying cancer.
- Application of quality-by-design approach in the analytical method development for quantification of sugars in sugarcane honey by reversed-phase liquid chromatographyPublication . Silva, Pedro; Silva, Catarina L.; Perestrelo, Rosa; Nunes, Fernando M.; Câmara, José S.Produced in Madeira Island from regional sugarcane cultivars through a traditional manufacturing and storage process, sugarcane honey (SCH) is a black syrup recognized by its excellent quality. Its economic value has led to the emergence of adulterated SCH, whereby the identification of molecular markers became an essential task in order to overcome the fraudulent activities, protect its authenticity, and guarantee the consumer safety. In the present study, an analytical strategy based on ultrasound-assisted liquid liquid extraction (USA-LLE) followed by reversed-phase liquid chromatography with a refractive index detector (LC-RI) was developed for the determination of sugars (glucose, fructose, sucrose, xylose, and mannose) in SCH samples from certified producers, supported on analytical quality-by-design (AQbD) approach, as a useful tool to establish its typicality. The application of AQbD was based on analytical risk assessment, multivariate statistics and quality control procedures for definition of the Method Operable Design Region (MODR). The optimal conditions into MODR were accomplished using BEH Amide column operating at a temperature of 80 °C and a flow rate of 300 μL min−1 , with a mobile phase composed by acetone and water (85:15, v v−1 ) at a flow rate of 1.0 mL min−1 . The robustness was determined by Monte Carlo simulation and capability analysis. The concentration-response function for all sugars was described by polynomial models. Accuracy was presented by recovery values between 98.2 and 119.5%. The analytical figures of merit validated the utility of AQbD in the systematic design of a LC-RI method with fine sensitivity for sugar analysis in SCH.
- Behind the scenes of anthocyanins—From the health benefits to potential applications in food, pharmaceutical and cosmetic fieldsPublication . Câmara, José S.; Monica Locatelli; Pereira, Jorge A. M.; Oliveira, Hélder; Arlorio, Marco; Fernandes, Iva; Perestrelo, Rosa; Freitas, Victor; Bordiga, Matteo; Câmara, José; Augusto Machado Pereira, JorgeAnthocyanins are widespread and biologically active water-soluble phenolic pigments responsible for a wide range of vivid colours, from red (acidic conditions) to purplish blue (basic conditions), present in fruits, vegetables, and coloured grains. The pigments’ stability and colours are influenced mainly by pH but also by structure, temperature, and light. The colour-stabilizing mechanisms of plants are determined by inter- and intramolecular co-pigmentation and metal complexation, driven by van der Waals, π–π stacking, hydrogen bonding, and metal-ligand interactions. This group of flavonoids is well-known to have potent anti-inflammatory and antioxidant effects, which explains the biological effects associated with them. Therefore, this review provides an overview of the role of anthocyanins as natural colorants, showing they are less harmful than conventional colorants, with several technological potential applications in different industrial fields, namely in the textile and food industries, as well as in the development of photosensitizers for dye-sensitized solar cells, as new photosensitizers in photodynamic therapy, pharmaceuticals, and in the cosmetic industry, mainly on the formulation of skin care formulations, sunscreen filters, nail colorants, skin & hair cleansing products, amongst others. In addition, we will unveil some of the latest studies about the health benefits of anthocyanins, mainly focusing on the protection against the most prevalent human diseases mediated by oxidative stress, namely cardiovascular and neurodegenerative diseases, cancer, and diabetes. The contribution of anthocyanins to visual health is also very relevant and will be briefly explored.
- Bioactive compounds and antioxidant activity from spent coffee grounds as a powerful approach for Its valorizationPublication . Andrade, Carolina; Perestrelo, Rosa; Câmara, José S.Coffee is one of the world’s most popular beverages, and its consumption generates copious amounts of waste. The most relevant by-product of the coffee industry is the spent coffee grounds, with 6 million tons being produced worldwide per year. Although generally treated as waste, spent coffee grounds are a rich source of several bioactive compounds with applications in diverse industrial fields. The present work aimed at the analysis of spent coffee grounds from different geographical origins (Guatemala, Colombia, Brazil, Timor, and Ethiopia) for the identification of bioactive compounds with industrial interest. For this purpose, the identification and quantification of the bioactive compounds responsible for the antioxidant activity attributed to the spent coffee grounds were attempted using miniaturized solid-phase extraction (µ-SPEed), combined with ultrahigh-performance liquid chromatography with photodiode array detection (UHPLC-PDA). After validation of the µ-SPEed/UHPLC-PDA method, this allowed us to conclude that caffeine and 5-caffeoylquinic acid (5-CQA) are the most abundant bioactive compounds in all samples studied. The total phenolic content (TPC) and antioxidant activity are highest in Brazilian samples. The results obtained show that spent coffee grounds are a rich source of bioactive compounds, supporting its bioprospection based on the circular economy concept closing the loop of the coffee value chain, toward the valorization of coffee by-products.
- Bioconversion of organic waste by insects: a comprehensive reviewPublication . Shahida Anusha Siddiqui; Harahap, Iskandar Azmy; Osei-Owusu, Jonathan; Saikia, Trideep; Wu, Yuan Seng; Fernando, Ito; Perestrelo, Rosa; Câmara, José S.; Perestrelo, Rosa; Câmara, Joséfeed. However, the increase in global agricultural production also means an increase in waste generation, which is mostly improperly managed, especially in low- and middle-income countries where adequate waste man agement infrastructure is limited and inefficient. Consequently, organic waste has become a global burden due to its negative impact on the environment and human health. In this sense, insect-based bioconversion could be an economically viable, environmentally friendly, and technically feasible approach to organic waste management. Based on this review, organic wastes from agriculture, food industry, household, municipalities, and starch in dustry are considered as suitable substrates for bioconverter insects. Commonly used insects for bioconversion include the cricket, yellow mealworm, superworm, black soldier fly, house fly, flesh fly and blow fly. Rearing facilities must be adapted to provide the optimal environmental conditions for the growth and development of the reared insect to maximize the bioconversion rate and efficiency. Bioconverter insects and their by-products can be industrially processed into animal feed, fertilizer and biodiesel or extracted to isolate bioactive com pounds. The challenges associated with insect-based bioconversion include human and social acceptance, method-, infrastructure- and technology-related problems, the availability of substrates, and political and legal regulations. In summary, insect-based bioconversion of organic waste has the potential to reduce waste, create jobs, provide novel products, and offer a sustainable source of protein to feed the world’s growing population.
- 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.
- Chemical/instrumental approaches to the evaluation of wine chemistryPublication . Perestrelo, Rosa; Câmara, José S.