Browsing by Author "Amaral, Joana S."
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- Adulteration of Brain Health (Cognitive, Mood, and Sleep Enhancement) Food Supplements by the Addition of Pharmaceutical Drugs: A Comprehensive Review of Analytical Approaches and TrendsPublication . Paiva, Rafael; Correia, Manuela; Delerue-Matos, Cristina; Amaral, Joana S.In recent years, the consumption of dietary supplements has grown worldwide, particularly in developed regions. However, this growing market has also become a prime target for adulteration practices, with some manufacturers illegally adding pharmaceuticals into plant-based food supplements (PFS) to enhance their effects. While extensive research has focused on detecting adulterant drugs in PFS tailored for improving sexual performance, weight loss, and muscle building, less attention has been given to supplements intended for mood enhancement, sleep aid, and cognitive function (nootropics). Nonetheless, recent reports indicate an increasing level of adulteration within this group of PFS. Therefore, this review aims at providing a comprehensive overview on the adulteration of PFS tailored for brain health, with a focus on the analytical techniques utilized for detection while also presenting data on consumption patterns and the prevalence of reported adulterants. Considering that the detection of such fraudulent practices primarily relies on chromatographic techniques coupled with mass spectrometry (MS), the developments in this field comprising either targeted or untargeted analysis of pharmaceutical adulterants are discussed.
- Adulteration of Dietary Supplements by the Illegal Addition of Synthetic Drugs: a reviewPublication . Rocha, Tiago; Amaral, Joana S.; Oliveira, BeatrizIn the last few years, the consumption of dietary supplements, especially those having plants as ingredients, has been increasing due to the common idea that they are natural products posing no risks to human health. In the European Union and the United States, dietary supplements are legally considered as foods/special category of foods, thus are not being submitted to any safety assessment prior to their commercialization. Among the issues that can affect safety, adulteration by the illegal addition of pharmaceutical substances or their analogs is of major concern since unscrupulous producers can falsify these products to provide for quick effects and to increase sales. This review discusses the various classes of synthetic drugs most frequently described as being illegally added to dietary supplements marketed for weight loss, muscle building/sport performance and sexual performance enhancement. Information regarding regulation and consumption is also presented. Finally, several conventional and advanced analytical techniques used to detect and identify different adulterants in dietary supplements and therefore also in foods, with particular emphasis on plant food supplements, are critically described. This review demonstrates that dietary supplement adulteration is an emerging food safety problem and that an effective control by food regulatory authorities is needed to safeguard consumers.
- Advances in Authenticity Testing for Meat SpeciationPublication . Amaral, Joana S.; Meira, L.; Oliveira, Beatriz; Mafra, IsabelNowadays, and particularly after the horse meat scandal in Europe, consumers are increasingly aware of the problem of food adulteration and consequently demand clear and reliable information about the composition of foods they are buying and eating. Meat, a highly appreciated premium source of protein, is among the foods most prone to suffer adulteration for economic gain. According to EU legislation laying down the general principles and requirements of food law (European Commission, 2002) and EU labeling regulations (European Commission, 2001), meat products should be accurately labeled regarding their species content, with food adulteration and misleading information being considered illegal. However, because of its high demand and value, frauds in the meat industry and retail markets have become a widespread problem, especially in ground and comminuted meat products.
- An antibiogram classification system based on an hybrid hough transform and gradient approachPublication . Ferreira, Rayssa Lopes Dantas; Amaral, Joana S.; Igrejas, Getúlio; Rodrigues, Pedro JoãoThe antibiogram performed by the disc diffusion method is a test frequently used in clinical microbiology. In this test, the result is given by the diameter of the inhibition zone formed around the antibiotic disc. In general, this measurement is performed manually. The main objective of this work was to develop an automatic image analysis system to assess the susceptibility of microorganisms to different antibiotics. As a first step, several images of antibiograms were obtained. Subsequently the images were subjected to image processing techniques. After the elimination of noise, the Hough transform was used to detect the antibiotic discs. Next, from the center of each identified disc, the inhibition zone was detected recurring to a gradient method. According to the diameter of the inhibition zone a susceptibility classification was made. The results prove the validity of the developed tool to detect the antibiotics discs and to segment the inhibition zones used in microorganism’s susceptibility evaluation.
- An antibiogram classification system based on an hybrid hough transform and gradient approachPublication . Ferreira, Rayssa Lopes Dantas; Amaral, Joana S.; Igrejas, Getúlio; Rodrigues, Pedro JoãoThe antibiogram performed by the disc diffusion method is a test frequently used in clinical microbiology. In this test, the result is given by the diameter of the inhibition zone formed around the antibiotic disc. In general, this measurement is performed manually. The main objective of this work was to develop an automatic image analysis system to assess the susceptibility of microorganisms to different antibiotics. As a first step, several images of antibiograms were obtained. Subsequently the images were subjected to image processing techniques. After the elimination of noise, the Hough transform was used to detect the antibiotic discs. Next, from the center of each identified disc, the inhibition zone was detected recurring to a gradient method. According to the diameter of the inhibition zone a susceptibility classification was made. The results prove the validity of the developed tool to detect the antibiotics discs and to segment the inhibition zones used in microorganism’s susceptibility evaluation.
- An antibiogram classificattion system based on an hybrid hough transform and gradient approachPublication . Ferreira, Rayssa Lopes Dantas; Amaral, Joana S.; Igrejas, Getúlio; Rodrigues, Pedro JoãoThe antibiogram performed by the disc diffusion method is a test frequently used in clinical microbiology. In this test, the result is given by the diameter of the inhibition zone formed around the antibiotic disco In general, this measurement is performed manually. The main objective of this work was to develop an automatic image analysis system to assess the susceptibility of microorganisms to different antibiotics. As a first step, several images of antibiograms were obtained. Subsequently the images were subjected to image processing techniques. After the elimination of noise, the Hough transform was used to detect the antibiotic discs. Next, from the center of each identified disc, the inhibition zone was detected recurring to a gradient method. According to the diameter of the inhibition zone a susceptibility classification was made. The results prove the validity of the developed tool to detect the antibiotics discs and to segment the inhibition zones used in microorganism's susceptibilfty evaluation.
- Analysis of a vegetable oil performance in a milling process by MQL lubricationPublication . Afonso, Inês Santos; Pereira, J.A.; Ribeiro, António E.; Amaral, Joana S.; Rodrigues, Nuno; Gomes, José R.; Lima, Rui A.; Ribeiro, J.E.In this work, we carried out a comparison between the dry machining of an aluminum block with conventional cutting oil and a block with vegetable oil. The two oils had different flow rates. Using the Taguchi method, it was possible to determine the matrices for optimizing the best parameters for each group of tests. Then, we studied the utility of using vegetable oil as a cutting lubricant. We found that the vegetable oil studied in this work had good properties in terms of reducing cutting temperatures but was less effective than conventional cutting oil in reducing the surface roughness of the machined part. Tribological tests were carried out to understand the influence of the selected lubricants in reducing friction and wear. After the sliding experiments, which were performed without lubrication in the presence of the same lubricants that were used in the machining tests and in the presence of distilled water, we concluded that vegetable oil has satisfactory lubricating properties that are similar to those of the conventional cutting fluid, indicating a potential for consideration as an effective alternative to the conventional cutting fluid, with economic, environmental, and health advantages.
- Analysis of pharmaceutical adulterants in plant food supplements by UHPLC-MS/MSPublication . Paíga, Paula; Rodrigues, Manuela J.E.; Correia, Manuela; Amaral, Joana S.; Oliveira, Beatriz; Delerue-Matos, CristinaA method based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was successfully developed and validated for the analysis of 26 pharmaceutical compounds belonging to different therapeutic classes (anorexics, stimulants, anxiolytics, antidepressants and laxatives), which are all prone to be illegally added into weight-loss plant food supplements (PFS) for their pharmacological activity. Internal standard calibration with six isotopically labelled compounds rendered good linearity in the range of 5 to 1000 μg/l, depending on the compound, and good sensitivity with limits of quantification in the range of 0.02–9.80 μg/l. Recoveries were assessed for all the 16 samples analysed and were found between 70% and 120% for over 90% of the analytes. The average recovery value was 90.8%, for the different studied matrices (liquids, liquid ampoules, tablets and capsules), with RSD values lower than 10% for all forms. The changes introduced to the QuEChERS procedure maintained the good performance characteristics of the extraction method while preserving the chromatographic system for the introduction of unwanted matrix compounds. Synephrine was the only compound detected and quantified in one sample, but at a very low concentration (768 μg/l) and its presence may be due to the plant extracts used in the formulation, as synephrine is known to be a natural constituent of Citrus aurantium amara. Despite none of the 16 evaluated samples were found to be adulterated by the illegal addition of the drugs included in this work, the developed methodology can be very useful for monitoring the adulteration of weight-loss PFS.
- Analysis of phenolic compounds from hazelnut (Corylus avellana L.) leavesPublication . Amaral, Joana S.; Ferreres, Frederico; Santos, Alberto; Pinheiro, Cristina; Andrade, Paula B.; Seabra, Rosa M.Hazelnut leaf has been used in folk medicine in varicose veins and haemorrhoidal symptomatology for its vasoconstrictor and antihaemorrhagic properties. Slight antidysenteric, antifungal and healing properties have also been described
- Animal species authentication in dairy productsPublication . Mafra, Isabel; Honrado, Mónica; Amaral, Joana S.Milk is one of the most important nutritious foods, widely consumed worldwide, either in its natural form or via dairy products. Currently, several economic, health and ethical issues emphasize the need for a more frequent and rigorous quality control of dairy products and the importance of detecting adulterations in these products. For this reason, several conventional and advanced techniques have been proposed, aiming at detecting and quantifying eventual adulterations, preferentially in a rapid, cost-effective, easy to implement, sensitive and specific way. They have relied mostly on electrophoretic, chromatographic and immunoenzymatic techniques. More recently, mass spectrometry, spectroscopic methods (near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR) and front face fluorescence coupled to chemometrics), DNA analysis (real-time PCR, high-resolution melting analysis, next generation sequencing and droplet digital PCR) and biosensors have been advanced as innovative tools for dairy product authentication. Milk substitution from high-valued species with lower-cost bovine milk is one of the most frequent adulteration practices. Therefore, this review intends to describe the most relevant developments regarding the current and advanced analytical methodologies applied to species authentication of milk and dairy products.