DAN - Posters/abstracts em congressos internacionais
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- Accuracy evaluation in thiamin quantification in food matricesPublication . Flores, Cristina; Dias, M. Graça; Santos, MarianaThe performance evaluation of an RP-HPLC method to determine thiamine using different food matrices and reference materials, showed the method suitability to its purpose and to be submitted to accreditation. Intermediate precision evaluate through the relative standard deviation (RSD%) was under 8% for all food matrices tested an all the z-scores obtained for the reference materials were < 1.5.The estimated expanded measurement uncertainty was 13%.
- Accuracy in niacin quantification in food matrices, by an RP-HPLC methodPublication . Flores, Cristina; Dias, M. Graça; Santos, MarianaAim: This work intended to evaluate accuracy of niacin quantification in food matrices, by an RP-HPLC method, in order to validate it for four different food groups: legumes, grains, dairy products and fish. Material and methods: Analytical methodology The analytical method was a RP-HPLC with fluorometric detection, based on EN 15652:2009. Samples (1 to 10 g) were submitted to an acid hydrolysis with 0.1 mol/l HCl for 30 min in an autoclave at 121ºC. After filtration, 50 µl of the solutions, were injected and separated at 37 ºC on a HPLC system. The stationary phase was the Fortis C18 5 µm (150 x 4,6 mm) column and the mobile phase consisted of 0.07 mol/l phosphate buffer, 0.075 mol/l hydrogen peroxide and 5x10-6 mol/l copper sulphate, at a flow rate of 1 ml/min. Excitation and emission wavelengths were 322 nm and 380 nm, respectively. Quantification was made with five external standards. Results were expressed in mg/100g. Accuracy evaluation To evaluate precision, at least one matrix of each food group was chosen: roasted peanuts, canned green peas, wheat bran, powder milk and canned tuna. Method trueness was assessed by testing five different reference materials from FAPAS and NIST. Each of the FAPAS samples 2160, 2166, 2172, 2176 (Breakfast Cereals) were tested once over a period of 14 months and, NIST 1849 (Infant/Adult Formula) was tested twice in the same period. In the precision study, the five matrices were tested in triplicate in four different days. Repeatability and intermediate precision standard deviations (Sr and SPi) were calculated, for each matrix, trough ANOVA (p < 0.05). Repeatability and Intermediate precision limits; r and Pi were calculated using the following formulas: r=2.8*S_r and Pi=2.8*S_Pi . Trueness was evaluated from the z-scores obtained. Results: The values of niacin concentration obtained were: peanuts – 13.4 mg/100 g, green peas – 0.59 mg/100 g, wheat bran – 18.2 mg/100 g, powder milk – 0.73 mg/100 g and tuna – 9.5 mg/100 g. The Sr and SPi (mg/100g) were respectively 0.52 / 1.25 (peanuts), 0.02 / 0.05 (green peas), 0.23 / 0.78 (wheat bran), 0.02 / 0.06 (powder milk) and 0.24 / 0.60 (tuna). The r and Pi values obtained ranged from 0.05 to 1.46 for r and 0.14 to 3.50for Pi. All the │z-scores│ obtained for FAPAS samples were < 1 and, the │z-scores│ obtained for NIST reference material were both < 2. Conclusion: The repeatability data obtained in this study, for niacin in different food matrices were in accordance with the ones presented in the method standard EN 15652:2009. Trueness evaluation using breakfast cereals and formulas revealed a good method/laboratory performance. Accuracy evaluation, using representative matrices and niacin contents, showed the method suitable to its purpose and fit to be submitted to accreditation by an external entity.
- Accuracy of labelled nutrition declaration among cereal productsPublication . Albuquerque, T.G.; Nunes, M.A.; Oliveira, M.B.P.P.; Costa, H.S.Introduction: In the last years, consumers are paying increasing attention to the nutritional composition of foods, in order to make healthier food choices, and therefore to prevent chronic diseases. The European Union has faced the challenge of standardizing the nutritional declaration of prepacked foods. Therefore, in 2011, Regulation (EU) No. 1169/2011 on the provision of food information to consumers was published (1). Accordingly, and concerning the declared values on the nutrition declaration, they should be an average and can be obtained by: (a) the manufacturer’s analysis of the food; (b) a calculation from the known or actual average values of the ingredients used; and (c) a calculation from generally established and accepted data. However, the food nutrient content should not deviate markedly from labeled values, otherwise consumers can be misled. Therefore, a tolerance guide regarding the deviations of labeled values for the different nutrients for analytical control purposes has been set up (2). In our study, an analysis regarding the accuracy of labeled nutrition declaration in cereal products was performed. Materials and Methods: In 2015, twelve samples of cereal products (cereal bars and breakfast cereals) were selected from the major supermarket chains in Portugal. An Excel® form was filled out with the labeled information for each one of the selected foods. Afterwards, the same foods were analysed concerning their salt, total fat and fatty acids composition, according to the methods described by Albuquerque et al. (3). Then, all the information was used to perform an analysis of the accuracy of the declared values, considering the tolerance limits defined for salt, total fat and saturated fatty acids (SFA). Results: Considering salt, in two (17%) of the selected foods, the declared values were not in compliance with the tolerance limits, being the analytical values lower than the lower tolerance value. The comparison between declared and analytical values for total fat shows that all the selected foods were within the tolerance limits fixed for this nutrient. On the other hand, for SFA, 33% of the samples were out of the tolerance limits, but from those samples, only one had an analytical value (10.3 g/100 g) higher than the upper tolerance value (4.7 g/100 g). Discussion and Conclusions: Food labels, namely nutrition declaration, are the most direct source of information for consumers. Therefore, it is very important that these labels provide accurate information in order to allow consumers to make informed and healthier dietary choices. In our study, SFA values were the ones for which a higher number of samples was out of the tolerance limits. References: (1) European Parliament/Council of the European Union. Regulation (EU) No 1169/2011 of the European Parliament and of the Council of 25 October 2011 on the provision of food information to consumers. Official J Eur Union, 2011; L304: 18-63. (2) European Commission. Guidance document for competent authorities for the control of compliance with EU legislation. 2012. Available at: https://www.fsai.ie/uploadedfiles/guidance_tolerances_december_2012.pdf. (3) Albuquerque TG, Oliveira MBPP, Sanches-Silva A, Bento AC, Costa HS. The impact of cooking methods on the nutritional quality and safety of chicken breaded nuggets. Food Func. 2016; 7: 2736-46.
- Acrylamide determination in Portuguese food matrices by UPLC-PDA and UPLC-MSPublication . André, Catarina; Delgado, Inês; Jesus, Susana; Castanheira, IsabelThe aim of this study was the determination of acrylamide in Portuguese food matrices thought the development and optimization of a chromatographic method with two different detectors. Acrylamide is classified by the International Agency for Research on Cancer (IARC) as a probable carcinogenic compound and the growing concern in human food is due to the fact that it was found in some foods when processed at high temperatures. Samples were bought randomly in local supermarkets and correspond to foods that suspect to contain high levels of this compound and contribute significantly to human consumption such as bolo do caco, fries, breakfast cereals, biscuits, coffee, coffee substitutes and pastel de nata. Sample preparation involved solid phase extraction. To quantify acrylamide were developed two chromatographic methods, UPLC-PDA and UPLC-MS/MS. The method who proved to be more suitable and quantify unequivocally acrylamide was UPLC-MS/MS. The chosen foodstuff for acrylamide determination presented a dissimilar range of values. Bolo do caco values depends on the cocking procedures. The lowest cooking temperature yield a lower acrylamide content (669 µg/Kg) while with the two samples cooked with the highest temperature the acrylamide content was must higher (1653 µg/Kg). In fries the content of acrylamide found was approximately 365 µg/Kg, while for breakfast cereals it varies between 238 and 187 µg/Kg depending on chocolate content. The content found was 58 µg/Kg for crackers and 203 µg/Kg for gingerbread. Coffee substitutes presented a value 5 times more than the coffee which was the lowest value determined with an acrylamide value of 25 µg/Kg. According to EFSA acrylamide values for pastry are between 75 and 1044 µg/Kg and the content of pastel de nata was 331 µg/Kg. The acrylamide content in all samples of Portuguese products analyzed were below the indicative values published by EFSA and are not considered to be main hazards of concern.
- Acrylamide mitigation in bakery productsPublication . Jesus, Susana; Delgado, Inês; Brandão, Carlos; Galhano dos Santos, Rui; Castanheira, IsabelThe aim of this study was the determination of acrylamide in Portuguese bakery and its reduction in a bakery product. Acrylamide is considered by the International Agency for Research on Cancer as a carcinogenic compound to animals and probably to humans. For this study a total of 30 samples of god bread, “trouxa filó”, pies, ham and cheese rollings, muffins, pastels, and cookies were randomly collected in several commercial establishments. Sample preparation involved solid phase extraction and for the quantification of acrylamide a ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) was used. The ham and cheese rolling and “trouxa filó” had the highest amount of acrylamide, 3743 µg/kg, and 3862 µg/kg, respectively. The results also showed that caramel cookies, butter cookies, Greek cookies and cocoa cookies do not exceed the EFSA indicative value (500 μg/kg) (EFSA, 2015). Pie samples(686-1084 μg/kg), god's bread(995 μg/kg), pastels(527-809 μg/kg) and muffins(676-1057μg/kg) contain high levels of acrylamide when compared to the values found in the literature for bakery products, 198 μg/kg (Mojska, Gielecińska, Szponar, & Ołtarzewski, 2010). Given the obtained results, tests were carried out in order to reduce the concentration of acrylamide. A bakery product was prepared to which four different reducing agents (A, B, C and D) were individually added. The effect of each agent on acrylamide formation was evaluated. Results showed that mixture B obtained an acrylamide reduction of 5.6%. On the other hand, the remaining mixtures increased the production of the contaminant. Yet, it was found that the decrease obtained with mixture B is still not sufficient since it remains above the indicative value of EFSA. Thus, further studies are necessary in order to achieve a higher percentage of reduction of acrylamide. Progress studies are ongoing with other reducing agents and flours.
- Active Packaging Produced by Extrusion with Shrimp Waste: Migration of Astaxanthin into Food SimulantsPublication . Sanches-Silva, A.; Ribeiro, T.; Albuquerque, T.G.; Paseiro, P.; Sendón, R.; Bernaldo de Quirós, A.; López-Cervantes, J.; Sánchez-Machado, D.; Soto Valdez, H.; Angulo, I.; Pardo Aurrekoetxea, G.; Costa, H.S.Introduction: Astaxanthin (3,3’-dihydroxy-β-β´-carotene-4-4´-dione), a potent antioxidant, is one of the major carotenoids in crustaceans. In the frame of the project ‘Preparation of active packaging with antioxidant and antimicrobial activity based on astaxanthin and chitosan’, a methodology for the incorporation of compounds obtained from shrimp waste in plastic matrices was developed to produce an active packaging with antioxidant properties. The aim of the present work was to develop and optimize a method to determine astaxanthin by ultra-high pressure liquid chromatography in fermented shrimp waste. Moreover, the method was also applied to determine the migration of astaxanthin from plastic films containing different amounts of shrimp waste to food simulants. Material and Methods: The method was optimized to determine astaxanthin by ultra-high pressure liquid chromatography (UHPLC) with diode array detection (DAD). The chromatographic separation was achieved using a vanguard pre-column (UPLCÒ BEH, 1.7 µm particle size) and a column (UPLCÒ BEH, 2.1 x 50 mm, 1.7 µm particle size) at 20 °C. The mobile phase was a gradient of A (dichloromethane/methanol with ammonium acetate/acetonitrile 5:20:75 (v/v)) and B (ultrapure water) with a flow rate of 0.5 mL/min. The optimized UPLC method allowed an excellent resolution of astaxanthin. The method was also evaluated in what concerns to validation parameters such as linearity, precision, limit of detection, limit of quantification and recovery. Low density polyethylene plastic films produced by extrusion with different amounts of the lipid fraction of shrimp waste were prepared and tested regarding migration into fatty food stimulants (isooctane and ethanol 95%, v/v). Results and conclusion: The proposed method to determine astaxanthin in shrimp waste is simple and has a low detection level (0.054 μg/mL). The concentration of astaxanthin found in the lipid fraction of fermented shrimp waste was 453.8 μg/g. The films produced by extrusion with the lipid fraction of the fermented shrimp waste did not originate astaxanthin migration into the tested fatty food simulants. Further studies could be made in order to evaluate the capacity of these films in protecting packed food from oxidation.
- Activity of chitosan films against different microorganismsPublication . Sanches-Silva, A.; Maia, C.; Furtado, R.; Ribeiro, T.; Paseiro, P.; Sendón, R.; Rodríguez-Bernaldo de Quirós, A.; López-Cervantes, J.; Sánchez-Machado, D.I.; Bueno, C.; Soto Valdez, H.; Angulo, I.; Aurrekoetxea, G.P.; Bilbao, A.; Costa, H.S.Chitosan is a hydrophilic polysaccharide which derives from chitin by deacetylation. It has several applications, namely as a film that can be applied to preserve the quality and increase the shelf-life of food. Chitosan is insoluble in most solvents but it is soluble in dilute organic acids such as formic acid and acetic acid[1]. The properties of chitosan depend on the degree of deacetylation (DA) and molecular weight (MW). A broad antimicrobial activity has been attributed to chitosan, either for gram-negative, gram-positive bacteria and fungi. The aim of the present study is to evaluate the antimicrobial activity of a chitosan film prepared by casting. The chitosan was obtained from shrimp waste collected from shrimp processing factories of South Sonora (Mexico). Four bacteria (Bacillus cereus; Escherichia coli; Staphylococcus aureus and Listeria monocytogenes) and one fungus (Botrytis cinerea) were evaluated. Although L. monocytogenes and B. cinerea growth was not inhibited by the chitosan film, results showed a clear growth-inhibitory effect, at the two bacteria concentration levels tested, for B. Cereus, E. coli and S. aureus. Different antibacterial mechanisms have been proposed to explain chitosan antimicrobial activity[2-3]: i) chitosan may form an external barrier which inhibits essential nutrients adsorption; ii) chitosan can also penetrate the microbial cell, disturbing the metabolism of the cell by inhibiting the mRNA and protein synthesis; iii) chitosan may have an ionic surface interaction with the bacteria originating wall cell leakage. Although these mechanisms may take place simultaneously, the antimicrobial activity may also depend on the properties of chitosan (DA and MW).
- Advances in phenolic compounds analysis of aromatic herbs and their potential applications.Publication . Carvalho-Costa, D.; Costa, H.S.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.; PhenolicIntroduction: Herbs can be considered important sources of antioxidants and have a long history of medicinal and culinary applications. The use of plants as sources of antioxidants for nutritional and preservation purposes in the food industry is currently growing. Materials and Methods: An extensive bibliographic review on the methods for analysis of phenolic compounds present in herbs was carried out. Results, Discussion and Conclusion: Plant derived phenolic compounds can be divided in four groups: phenolic acids, phenolic diterpenes, flavonoids and volatile compounds. Considering the first three groups, the identification and quantification of the compounds in the literature is accomplished using High Performance Liquid Chromatography while for volatile compounds, the identification and quantification is accomplished with Gas Chromatography. Several herbs, such as sage (Salvia officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), oregano (Origanum majorana), dandelion (Taraxacum officinale), peppermint (Mentha piperita) and basil (Ocimum basilicum) were analyzed in different studies regarding their phenolic compounds. The major phenolic acids found in herbs were ferulic, caffeic, neochlorogenic and rosmarinic. In terms of phenolic diterpenes, carnosol, rosmanol and carnosic acid were the most reported. Regarding flavonoids, luteolin, quercetin and apigenin were predominant. Concerning volatile compounds, thymol, carvacrol and eugenol were the most common. The herbs with more antioxidant potential regarding their composition on phenolic compounds were compared and the potential of utilisation of these food matrices for newer applications such as active packaging was discussed.
- Aflatoxin B1 accumulation in Tenebrio molitor: a preliminary assessmentPublication . Andrade, M.A.; Cardoso, D.N.; Silva, A.R.R.; Prodana, M.; Santos, J.; Loureiro, S.; Alvito, PaulaWith the population growth rate, there are some concerns that food production will not be able to keep up with this growth. Edible insects seem to present a sustainable solution. Farming these insects presents an opportunity to drain the production of the by-products by reusing them as bio-feedstocks and reintroducing these components into the food value chain. However, these products can present several contaminations, including mycotoxins, which can be accumulated in insects after exposure to the contaminant, and be detected at the end of the food chain. The ENTOSAFE project aims to address these concerns and evaluate the potential risk for the consumer. The principal aim of this study was to evaluate the mycotoxin aflatoxin B1 (AFB1) accumulation in Tenebrio molitor (yellow Mealworm, YMW) exposed to a spiked AFB1 feed subtract at maximum levels in cereals and products derived from cereals (2 µg/kg) and ten times higher (20 µg/kg). AFB1 contents were quantified in both feed substrate and T. molitor samples, before and after a 14-days of exposure and mycotoxins (aflatoxins and ochratoxin A, OTA), detected by HPLC-FD detection. Results concerning non-contaminated feed substrate revealed absence of AFB1 and presence of OTA, the latter (0,8 µg/kg) presenting values below the legislated value of 3 µg/kg, for cereals and products derived from cereals (European Commission, 2023). AFB1 spiked feed substrates revealed values slightly higher (4 and 23 µg/kg) than the theoretical contamination levels of 2 and 20 µg/kg. OTA values remain close to the previously reported. No changes occurred in contamination levels at beginning and 14-days AFB1 exposure assays. Results concerning T. molitor larvae, revealed absence of OTA along exposure assays and different AFB1 contamination levels. AFB1 contents in low (0.011 µg/kg) and high (0.022 µg/kg) AFB1 contamination levels were close, and below the 2 µg/kg legislated level for cereals and products derived from cereals (European Commission, 2023), after the 14-days exposure. The reported results are preliminary, so several aspects need to be improved as mycotoxin analytical method validation, mycotoxin contamination procedure and a higher number of samples to get representative results on AFB1 accumulation in insect larvae.
- Aflatoxin B1 and early life gut microbiota: preliminary results under earlyMYCO projectPublication . Silva, I.; Duarte, E.L.; Bastos-Amador, P.; Ferreira, M.; Alvito, P.; Assunção, R.; Salvador, C.; Caldeira, A.TAflatoxin B1 (AFB1) produces acute or chronic deleterious health effects in humans and animals. Still, long-term effects derived from initial exposure in early-life, a critical period for colonization and development of gut microbiota, has not been fully evaluated, . particularly, effects on gut microbiota and immunity system. This study, performed under the earlyMYCO project, investigated the impact of maternal exposure to AFB1 on early-life microbiota in a mouse model. Females were fed jelly pellets containing 400 µg/kg AFB1 diluted in DMSO (treated animals n=6) or DMSO vehicle alone (control group n=6) during pregnancy and lactation. Faeces from the offspring were collected immediately after weaning and faecal DNA was extracted and purified. Bacterial taxa diversity and relative abundance were assessed by High-Throughput Sequencing performed in an Illumina Miseq® sequencer, targeting the V3 and V4 regions of the 16S rRNA gene. Operational taxonomic units (OTUs) were determined by clustering reads to 16S reference databases. A hundred and twenty-four (N=124) bacterial genera were found in both groups, 5 were only present in AFB1 treated group and 27 exclusively in control groups. A hundred and fifty-one (N=151) bacterial species were common to both groups, 15 species exclusively found in AFB1 litters and 34 species were exclusively found in control litters. Although present in both groups, Akkermansia muciniphila and Bacteroides acidifaciens were significantly higher in controls. A. muciniphila colonizes the intestinal tract in childhood and regulates mucus thickness, intestinal barrier integrity and is involved in immune modulation. B. acidifaciens participates in the metabolism of lipids and sugars and activates some cytokines and immune cell receptors. Sulfidogenic bacteria, recently related to inflammatory bowel disease, such as Desulfovibrio piger and Bilophila wadsworthia were exclusivly found in the treated litters. Early-life gut microbiome triggers the gut immune defences, but is far less stable than the adult microbiome. These preliminary results open an extensive field to further investigate the association between mycotoxins and microbiome, as the latest is increasingly recognized as a major player in a wide spectrum of diseases.