Examinando por Autor "Perestrelo, Rosa"

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An improved and miniaturized analytical strategy based on μ-QuEChERS for isolation of polyphenols. A powerful approach for quality control of baby foods
(Elsevier, 2018-02-22) Casado, Natalia; Perestrelo, Rosa; L. Silva, Catarina; Sierra, Isabel; S. Câmara, José
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.
Comparison of high-throughput microextraction techniques, MEPS and -SPEed, for the determination of polyphenols in baby food by ultrahigh pressure liquid chromatography
(Elsevier, 2019-04-10) Casado, Natalia; Perestrelo, Rosa; L. Silva, Catarina; Sierra, Isabel; S. Câmara, José
In this study, two different high-throughput microextraction techniques, microextraction by packed sorbents (MEPS) and micro solid phase extraction (μ-SPEed®), were evaluated and compared, regarding the performance criteria, for the isolation of polyphenols from baby foods prior to their determination by ultrahigh pressure liquid chromatography (UHPLC). To achieve the best performance, influential parameters affecting extraction efficiency (including type of sorbent, number of extraction cycles, pH, elution solvent and elution volume) were systematically studied and optimized. To enable an effective comparison, selectivity, linear dynamic range, method detection (LODs) and quantification limits (LOQs), accuracy, precision and extraction yields, were determined and discussed for both techniques. Both methods provided the analytical selectivity required for the analysis of polyphenols in baby foods. However, μ-SPEed® sample treatment in combination with UHPLC-PDA has demonstrated to be more sensitive, selective and efficient than MEPS. Appropriate linearity in solvent and matrix-based calibrations, very low LODs and LOQs, ranging between 1.37 and 13.57 μg kg−1 and 4.57 – 45.23 μg kg−1, respectively, suitable recoveries (from 67 to 97%) and precision (RSD values < 5%) were achieved for the selected analytes by μ-SPEed®/UHPLC-PDA. Finally, the validated methodologies were applied to different commercial baby foods. Gallic acid, chlorogenic acid, epicatechin, ferulic acid, rutin, naringenin and myricetin are the most dominant polyphenols present in the studied baby food samples. The proposed methodology revealed a promising approach to evaluate the nutritional quality of this kind of products.
High throughput analytical approach based on μQuEChERS combined with UHPLC-PDA for analysis of bioactive secondary metabolites in edible flowers
(Elsevier, 2022-11) Izcara, Sergio; Perestrelo, Rosa; Morante-Zarcero, Sonia; Câmara, José S.; Sierra, Isabel
Mallow blue (Malva sylvestris L.), hibiscus (Hibiscus rosa-sinensis L.) and nasturtium (Tropaeolum majus L.), are common edible flowers rich in bioactive secondary metabolites (BASMs) whose use in sophisticated gastronomy present currently as increasing trend. In this study the BASMs profile of these edible flowers was established using an emerging green extraction technique, μQuEChERS followed by ultra-high performance liquid chromatography coupled to a photodiode array detection system (UHPLC-PDA). After validation the μQuEChERS/UHPLC-PDA methodology allow to identify that apigenin and epigallocatechin gallate are the most abundant BASMs in mallow blue flowers, while catechin and dicaffeoylquinic acid are predominant in hibiscus flowers, and myricitrin and dicaffeoylquinic acid in nasturtium flowers. Total polyphenol content is the highest in the extract of hibiscus. Nasturtium shows the greatest radical scavenging activity. The results revealed that these flowers constitute a potential source of BASMs with different bioactive properties suggesting its use in design of new functional foods.
Spices Volatilomic Fingerprinting—A Comprehensive Approach to Explore Its Authentication and Bioactive Properties
(MDPI, 2022-09-28) Izcara, Sergio; Perestrelo, Rosa; Morante-Zarcero, Sonia; Sierra, Isabel; S. Câmara, José
Volatile organic metabolites (VOMs) present in different spices can provide distinct analytical biosignatures related to organoleptic properties and health benefits. This study aimed to establish the volatilomic fingerprint of six of the most consumed spices all over the world (saffron (Crocus sativus L.), cinnamon (Cinnamomum verum), cumin (Cuminum cyminum L.), black pepper, (Piper nigrum L.), sweet paprika (Capsicum annuum L.), and curry (a mix of different herbs and spices)). Based on headspace solid phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis, this is a powerful strategy to explore and establish the spice’s volatile pattern and unravel the potential health benefits related to the most important VOMs identified in each spice. This comprehensive knowledge will help in the definition of their authenticity, while simultaneously protecting against potential frauds and adulterations. A total of 162 VOMs were identified. Semi-quantitative assessments revealed that terpenoids and sesquiterpenoids amounted to the major volatile class in the investigated spices, except for cinnamon, where carbonyl compounds are the major group. Most of the studied spices comprised key characteristics of aroma and health bioactive compounds, e.g., dihydrojuneol in saffron, cinnamaldehyde in cinnamon, cuminaldehyde in cumin and curry, and caryophyllene in black pepper. The principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) successfully discriminated the investigated spices, being α-cubebene, 3-methyl butanal, β-patchoulene and β-selinene, the most important VOMs (highest VIP’s) that contributed to its discrimination. Moreover, some VOMs have a high influence on the spice’s bioactive potential, helping to prevent certain diseases including cancer, inflammatory-related diseases, diabetes, and cardiovascular diseases.
Volatilomic fingerprinting from edible flowers. Unravelling some impact compounds behind its attractiveness
(Elsevier, 2022-11) Izcara, Sergio; Perestrelo, Rosa; Morante-Zarcero, Sonia; Sierra, Isabel; S. Câmara, José
In recent years edible flowers emerged in gourmet cuisine, giving any dish the beauty of attractive colours, freshness, texture, and aromatic notes. Moreover, they also constitute a potential source of phytochemical compounds associated with beneficial effects on human health. In this work, the volatilomic fingerprinting of 4 different species of edible flowers [blue mallow (Malva sylvestris L.), pomegranate flower (Punica granatum L.), hibiscus (Hibiscus rosa-sinensis L.), and nasturtium (Tropaeolum majus L.)] used in gourmet dishes, was established, and comparatively investigated. The volatile metabolites were extracted by solid-phase microextraction in headspace mode and identified by gas chromatography-mass spectrometry to understand the chemistry behind its attractiveness better. A total of 78 volatile metabolites, belonging to diverse chemical groups were identified. Blue mallow is mainly characterised by sesquiterpenoids (61.5% of the total volatile fraction), whereas in flowers from pomegranate, hibiscus, and nasturtium, terpenoids (56.6%), carbonyl compounds (88.0%) and organosulfur compounds (98.0%) are the dominant chemical groups, respectively. In blue mallow flowers, τ-muurolene and valencene are the dominant volatiles, followed by α-cubebene and δ-cadinene. Pomegranate flowers are rich in furfural and linalool, while the aldehydes 2-hexenal, hexanal and 2-octenal are dominant volatile metabolites in hibiscus. Benzyl isothiocyanate, a potent antimicrobial agent, accounts for 98% of the total volatile fraction of nasturtium flowers. In addition to flavour notes, some of the identified volatile metabolites present bioactive properties, which could be explored for application in the food, pharmaceutical and cosmetic industries. The volatile metabolites profiles combined with unsupervised principal component analysis facilitated the differentiation of the edible flowers under investigation, revealing the most related volatile metabolites of each sample, which can be used as markers for the authentication of these valuable food samples.