Browsing by Author "Silva, Pedro"
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- 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.
- 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 Differentiation of Sugarcane Cultivars Based on Volatile Profile and Chemometric AnalysisPublication . Silva, Pedro; Freitas, Jorge; Nunes, Fernando M.; Câmara, José S.Sugarcane (SC) is a perennial grass widely cultivated in tropical and subtropical regions. However, its cultivation in Europe is residual, where Madeira Island, Portugal, is the only region where SC continues to be extensively cultivated. For the first time, the volatile profiles of regional cultivars were established by solid-phase microextraction combined with gas chromatography− mass spectrometry. Different volatile profiles for each cultivar were recognized, identifying 260 volatile organic compounds belonging to 15 chemical classes, such as aldehydes, alcohols, ketones, hydrocarbons, esters, and terpenes. Chemometric analysis procedure, namely, one-way ANOVA with Tukey’s test, principal component analysis, partial least-square analysis, linear discriminant analysis, and hierarchical clustering analysis, allowed the differentiation between all regional cultivars. This study represents an important contribution for the maintenance of biodiversity and subsistence of the SC industry in Europe. Furthermore, it is also a valuable contribution to establish the typicality of traditional SC-based products, such as SC honey.
- Current trends and recent advances on food authenticity technologies and chemometric approachesPublication . Medina, Sonia; Perestrelo, Rosa; Silva, Pedro; Pereira, Jorge A. M.; Câmara, José S.Background: Food frauds and counterfeit products produced to obtain economic advantages have become a growing concern over the last decade. The assessment of food safety and authenticity constitute a powerful tool to mitigate this problem and protect public health. Nevertheless, the growing sophistication of fraudulent practices requires a continuous update and improvement of the analytical methodologies. Scope and approach: In this context, the advances and novel techniques and chemometric approaches reported since 2016 are discussed regarding their potential use in food authentication. This review details the main analytical techniques applied in the extraction, detection and identification of metabolites to obtain food fingerprints, emphasizing the advantages and drawbacks of each approach with practical examples. Additionally, the current legislation on food authentication has also been revised. Key findings and conclusions: GC-MS, LC- q-TOF-MS and NMR followed by PCA and PLS-DA are the most often reported analytical methodologies to discriminate between authentic and non-authentic foodstuffs using chemical fingerprints. More recently, novel and promising statistical methods with high classification power (DDSIMCA, OO-SIMCA, BPR, k-NN, among others) are being already applied. Overall, the development of nondestructive, on-siteandreal-time analyticalprocedures abletodeliverfastandunambiguous foodauthentication results will continue to be the goal driving food research.
- Differentiation of fresh and processed fruit juices using volatile compositionPublication . Perestrelo, Rosa; Silva, Catarina; Silva, Pedro; Medina, Sonia; Câmara, JoséIn the current study, a comprehensive approach based on headspace solid-phase microextraction (HS-SPME), combined with gas chromatography-quadrupole mass spectrometry (GC-qMS), was used to establish the volatile signature of fresh and processed fruit juices, obtained from the same batch of grapes, red fruits, orange, pear, and apple. This is a powerful tool for evaluating the impact of the production process on the volatomic pattern of fruit juice. A total of 169 volatile organic compounds (VOCs) belonging to different chemical groups were identified. Esters, carbonyl compounds, terpenoids, and alcohols are the major chemical groups in the investigated fruit juices. However, their contribution to the total volatile profile varied. Special attention should be paid to processed fruit juices to avoid the possible deleterious effects associated with the formation of furanic compounds (e.g., heat treatment), since their furanic content was significantly higher in comparison to that of fresh fruit juices. The knowledge obtained in the current study will allow for the introduction of modifications to the process involved in processing juice, which will improve the organoleptic characteristics of processed juices, contributing to a better acceptance by consumers. Furthermore, more assays should be performed to assess the effect of harvests, geography, and agronomy on the volatile profile of juices.
- Effect of processing and storage on the volatile profile of sugarcane honey: A four-year studyPublication . Silva, Pedro; Freitas, Jorge; Nunes, Fernando M.; Câmara, José S.Sugarcane honey (SCH) is a syrup from Madeira Island recognized by its unique and excellent aroma, associated to volatile organic compounds (VOCs) generated during the well-defined five stages of its traditional making process. The establishment of volatile profile throughout all SCH-making stages during four years, allowed the evaluation of the influence of each stage in the typical characterisitcs of SCH. One hundred eighthy seven VOCs were identified, being associated to several origins and formation pathways. VOCs formed during stage 1 and 2 were originate from raw material, and its oxidation (i.e. enzymatic browning) and thermal degradation (i.e. lipid oxidation, Maillard reactions, Strecker degradation). In stage 3 and 4, the caramelization and melanoidin degradation also occurred, while in stage 5, the thermal degradation continues, followed by microbial activity. Chemometric analysis allowed to identify 35 VOCs as potential markers for processing control by the producers and as guarantee of the typicality and authenticity of SCH. Based on the obtained results, we propose for the first time an innovative schematic diagram explaining the potential reactions and pathways for VOCs formation during the different steps of the SCH production.
- Establishment of authenticity and typicality of sugarcane honey based on volatile profile and multivariate analysisPublication . Silva, Pedro; Freitas, Jorge; Silva, Catarina L.; Perestrelo, Rosa; Nunes, Fernando M.; Câmara, José S.Sugarcane honey (SCH) is a black syrup produced in Madeira Island widely known for their excellent quality being used in traditional pastry and confectionery. However, its notoriety has been affected by circumstances in which some producers do not guaranty the product quality. The purpose of this study was to establish, for the first time, the volatomic profile of SCH produced by certified and non-certified producers in order to define their authenticity and typicality as useful platform to ensure SCH safety, protect consumer interests and fight the continuous problems of food fraud and adulteration. Solid-phase microextraction in headspace mode (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was applied as high throughput approach for extraction, separation and identification of SCH volatile compounds. The extraction technique was optimized for nature of stationary phase, extraction temperature, extraction time, and validated according with IUPAC and AOAC guidelines. Different volatomic fingerprints for SCH from certified and non-certified producers were recognized, being identified up to 87 volatile organic compounds (VOCs) belonging to distinct chemical classes, mainly aldehydes, alcohols, ketones and furans. One-way ANOVA analysis showed the existence of 18 VOCs with statistically significant differences between volatile profiles from certified and non-certified producers. Principal component analysis (PCA) and linear discriminant analysis (LDA) differentiate and discriminate the samples from both type of producers. According to the obtained results, the followed strategy revealed an effective way to establish the authenticity and typicality of SCH, providing useful information to producers that might therefore be used to improve the SCH quality and a powerful platform to promote a European certification application.
- Establishment of the volatile signature of wine-based aromatic vinegars subjected to macerationPublication . Perestrelo, Rosa; Silva, Catarina L.; Silva, Pedro; Câmara, José S.The flavoring of vinegars with aromatic fruits and medicinal herbs is a practice with increasing trend mostly in countries with oenological tradition, resulting in a product of improved quality and consumer attractiveness. This study was directed towards the evaluation of the impact of the maceration process on the volatile signature of wine-based aromatic vinegars (WBAVs). The evaluation was performed using solid phase microextraction (SPME) combined with gas chromatography combined with mass spectrometry (GC-MS). Experimental parameters influencing headspace solid (HS)-SPME extraction efficiency, were optimized using an univariate experimental design. The best results were achieved using a polydimethylsiloxane (PDMS) fiber, 10 mL of vinegar sample,at50◦Cfor30minofextraction. ThiswayOnehundredandthreevolatileorganiccompounds (VOCs), belonging to different chemical families including ethyl esters (37), higher alcohols (20), fatty acids (10), terpenoids (23), carbonyl compounds (six), lactones (five) and volatile phenols (two), were identified in wine vinegar (control) and WBAV. As far as we know, 34 of these VOCs are reported for the first time in macerated vinegars. Higher alcohols and lactones are the major chemical families in WBAV macerated with apple, whereas terpenoids are predominant in WBAV macerated with banana. The obtained data represent a suitable tool to guarantee the authenticity and genuineness of WBAV, as well as to promote the production of WBAV with improved sensorial and organoleptic properties. To the best of our knowledge, there are no reported studies dealing with the volatile signature of WBAV enriched with banana, passion fruit, apple and pennyroyal.
- Fingerprint targeted compounds in authenticity of sugarcane honey: an approach based on chromatographic and statistical dataPublication . Silva, Pedro; Silva, Catarina L.; Perestrelo, Rosa; Nunes, Fernando M.; Câmara, José S.ugarcane honey (SCH) is a black syrup recognized by its excellent quality, being produced in Madeira Island using the regional sugarcane cultivars and following a traditional and peculiar manufacturing and storage processes. However, some low-quality commercial products have been labeled as SCH but do not respect its criteria, revealing the need of develop powerful strategies in order to detect and prevent adulterations. The knowledge of furanic derivatives (FDs) profile, produced during browning reactions that occurs during food processing and storage, emerged as a promising strategy in food quality and fraud prevention. Therefore, the aim of this study was to establish the FDs profiling of typical SCH produced by certified and non-certified producers, in different geographical regions (Madeira and Brazil), based on microextraction by packed sorbent (MEPS) combined with ultra-high performance liquid chromatography (UHPLC) as a useful approach to define its typicality and authenticity. These parameters are defined through the differentiation and discrimination of FDs profiles among other sugarcane-derived products using multivariate statistical analysis (ANOVA with post-hoc Tukey, principal components analysis, partial least square, linear discriminant analysis and hierarchical clustering). The results demonstrated that SCH samples from non-certified producers present the highest levels of FDs. In addition, SCH samples from Brazil present higher levels of FDs than samples from Madeira region. The obtained results revealed that the proposed approach is a valuable strategy to establish the typicality of SCH, ensuring its quality, authenticity, safety control and a useful support regarding the application of SCH from Madeira Island to EU certification.
- Food fingerprints: a valuable tool to monitor food authenticity and safetyPublication . Medina, Sonia; Pereira, Jorge A.; Silva, Pedro; Perestrelo, Rosa; Câmara, José S.In recent years, food frauds and adulterations have increased significantly. This practice is motivated by fast economical gains and has an enormous impact on public health, representing an important issue in food science. In this context, this review has been designed to be a useful guide of potential biomarkers of food authenticity and safety. In terms of food authenticity, we focused our attention on biomarkers reported to specify different botanical or geographical origins, genetic diversity or production systems, while at the food safety level, molecular evidences of food adulteration or spoilage will be highlighted. This report is the first to combine results from recent studies in a format that allows a ready overview of metabolites (<1200 Da) and potentially molecular routes to monitor food authentication and safety. This review has therefore the potential to unveil important aspects in food adulteration and safety, contributing to improve the current regulatory frameworks.
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