Browsing by Author "Jesus, Susana"
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- Acrilamida em cereais e derivados: validação do método analítico e resultados preliminaresPublication . Copeto, Sandra; Jesus, Susana; Delgado, Inês; Coelho, InêsA reação de Maillard, responsável pela cor, sabor e aroma dos alimentos, também produz substâncias nocivas, como a acrilamida (AA). Esta amida insaturada forma-se quando alimentos ricos em hidratos de carbono, como pão, batatas e café, são cozinhados a temperaturas elevadas e humidade baixa. A União Europeia classificou a AA como carcinogénica (Categoria 1B), mutagénica (Categoria 1B) e tóxica para a reprodução (Categoria 2). O presente estudo visa validar um método para determinar AA em cereais e derivados e investigar a sua presença em diferentes variedades desses produtos. Utilizou-se a cromatografia líquida de ultra eficiência acoplada a um detetor de massa (UPLC-MS/MS) com ionização por electrospray positiva (ESI+ ) para detetar e quantificar a AA. O desempenho do método foi validado utilizando testes de avaliação externa da qualidade internacionais como testes de proficiência (FAPAS) e material de referência certificado (ERM-BD272). Avaliaram-se parâmetros como linearidade, limite de deteção (LD), limite de quantificação (LQ), precisão, exatidão e incerteza. Os LD e LQ foram de 0,40 µg/L e 1,22 µg/L, respetivamente, em conformidade com o Regulamento (UE) 2017/2158. A curva de calibração mostrou linearidade (R2 > 0,995). O método apresentou boas taxas de recuperação (92%-105%) e de precisão (desvio padrão relativo (RSD) ≤ 13%), participação satisfatória em ensaios de comparação interlaboratorial (ECI) (Z-score: 0,69 para Crispbread e -0,93 para Biscuit), assim como bons resultados para o ERM-BD272, demonstrando que o método é adequado para a determinação de AA em cereais e derivados. O método foi aplicado a cereais e derivados existentes no mercado, incluindo bolacha Maria, pão de trigo, flocos de milho e bolachas para bebé, todos recolhidos em Lisboa, Portugal. Os resultados de AA das amostras avaliadas, expressos em µg/kg, encontram-se abaixo dos valores legislados pelo Regulamento (EU) 2017/2158. Embora os níveis de acrilamida encontrados cumpram os limites estabelecidos pela União Europeia, é necessária uma monitorização contínua da sua ocorrência, considerando as incertezas ainda presentes sobre os efeitos a longo prazo deste contaminante.
- Acrilamida em doçaria PortuguesaPublication . Jesus, Susana; Delgado, Inês; Ramos, Ana; Brandão, Carlos; Félix, Nelson; Castanheira, IsabelA acrilamida é um composto de estrutura vinílica, com propriedades carcinogénicas (Grupo 2A- IARC) que tem vindo a ser identificado, em alimentos processados, desde 2002. Segundo os últimos documentos publicados pela EFSA deve ser prioritário a determinação do teor de acrilamida em produtos de panificação e pastelaria. Este estudo teve como objetivo a determinação da quantidade de acrilamida em doçaria portuguesa. Trinta amostras de doces e pão fabricados em estabelecimentos hoteleiros do Norte, Centro e Sul do País, foram analisadas individualmente por UPLC-MS para quantificação do teor de acrilamida. Os resultados revelaram que de todas as amostras, os biscoitos de caramelo (110 µg/Kg), os biscoitos apertados (218.8 µg/Kg) e os biscoitos gregos (354.9 µg/Kg) são os que não excedem o valor indicativo da EFSA (500 µg/Kg). Quanto às amostras de tortas (686-1084 µg/Kg), pão de deus (994.5 µg/Kg), pastéis (526.7 – 809 µg/Kg) e queques (676 – 1057.7 µg/Kg) verificou-se que contêm maior quantidade de acrilamida quando comparado com o valor encontrado na literatura. No pão de trigo analisado e correspondente a uma receita nacional foi determinado um teor de acrilamida inferior a 600 µg/Kg. Perante os resultados obtidos, podemos inferir que a formação da acrilamida está relacionada com a receita seguida na confeção dos produtos, já que a temperatura de cozedura das massas foi superior a 120 °C. Os resultados analíticos encontrados aconselham à sua combinação com dados de consumo destes alimentos com vista à análise rigorosa da exposição a este contaminante por parte dos consumidores.
- 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.
- Acrylamide mitigation in rye and oat breadPublication . Jesus, Susana; Delgado, Inês; Brandão, Carlos; Galhano dos Santos, Rui; Castanheira, IsabelBackground and objective(s):Acrylamide is a carcinogenic substance for animals and to humans. The harmful effect of such compound was later confirmed, and recently the acrylamide was considered a neurotoxic and genotoxic substance1. This contaminant has been found in carbohydrate-rich foods since 20022. There are many studies regarding several mitigation strategies, however it is need to change the manufacturing processes3. The aim of the study was to reduce the acrylamide content in bread. Materials and methods:It was selected oat and rye breads which are consumed ones daily by the population. The confection trials of rye and oat breads were made with the addition of 15 polyphenols-rich additives separately. For detection and quantification of acrylamide was used the ultra-efficiency liquid chromatography coupled to a mass detector. Results:In oat bread was found that only one additive allowed 77.8% reduction of acrylamide. Such value was below of the indicative value published by EFSA, 150 μg/kg2. In rye bread was obtained a maximum reduction of 79%. Comparing the rye bread results with the indicative value of EFSA, only one bread was lower than 150 μg/kg2. However, further studies on the quantity of additives added are needed, due to the close results of the indicative value. Discussion and conclusion(s):In general, there was a wide variability in acrylamide levels among the two breads. These differences can be caused by the nutritional composition of each flour. A more detailed study of the mechanism of the reduction of these additives in different nutritional composition flours is, therefore, necessary. References: 1. Claeys, W. et al. Reassessment of the acrylamide risk: Belgium as a case-study. Food Control 59, 628–635 (2016). 2. EFSA. Scientific Opinion acrylamide in Food. EFSA Journal 8, (2015). 3. Pedreschi, F., Mariotti, M. S. & Granby, K. Current issues in dietary acrylamide: Formation, mitigation and risk assessment. J. Sci. Food Agric. 94, 9–20 (2014).
- Caracterização de Compostos Bioativos em Subprodutos de Arroz Cultivado em PortugalPublication . Delgado, Inês; Rego, Andreia; Jesus, Susana; Castanheira, IsabelPortugal é um dos principais produtores de arroz da Europa. Associado à sua produção ocorre um grande desperdício de subprodutos como o farelo e a casca, que podem causar detrimento ambiental. Atualmente, os resíduos agrícolas têm sido alvo de grande foco, no sentido de minimizar o desperdício destes subprodutos e consequentemente o detrimento ambiental que causam. Deste modo, têm sido feitos estudos científicos que revelam a existência de compostos antioxidantes nos subprodutos de arroz cultivado em diversas regiões fora da Europa. O objetivo deste trabalho foi caracterizar e identificar os compostos bioativos que possam ser extraídos, do farelo e da casca de arroz, cultivado em Portugal, para serem utilizados noutras indústrias, deste modo valorizando-os. O farelo e a casca analisados são provenientes de duas zonas principais de cultivo de arroz, o Sado e o Ribatejo e pertencem a duas variedades típicas de Portugal, a Japónica e Indica, comumente designadas por carolino e agulha, respetivamente. Os compostos bioativos foram extraídos pelo método de extração sólido-liquido, usando como solvente uma mistura aquosa de metanol. A caracterização da atividade antioxidante foi realizada através do teste da eliminação dos radicais livres de DPPH (2,2-difenil-1-picrilhidrazilo) e pelo método de Folin-Ciocalteau. Tendo-se verificado que as amostras provenientes do Ribatejo apresentavam uma maior capacidade antioxidante e conteúdo de fenólicos totais superior às do Sado. Sendo assim, a identificação dos compostos antioxidantes apenas foi realizada às amostras provenientes do Ribatejo, através da técnica de UPLC-PDA. Os ácidos p-cumárico, p-hidroxibenzoico, vanílico e elágico foram identificados na casca das duas variedades. O ácido ferúlico foi quantificado em todas as amostras.
- Contribution of metrology on determination of acrylamide in foodstuffsPublication . André, Catarina; Delgado, Inês; Jesus, Susana; Ramos, Ana; Brandão, Carlos; Félix, Nelson; Castanheira, IsabelThe aim of this study was the determination of acrylamide in food with high consumed in Portugal. Samples were bought randomly from local supermarkets and from Escola Superior de Hotelaria e Turismo do Estoril. Sample preparation involved SPE (Solid Phase Extraction). Two chromatographic methods were developed, UPLC-PDA and UPLC-MS/MS which was more suitable and quantify unequivocally acrylamide. The acrylamide content in bread and pastries samples analyzed were above the indicative values published by EFSA.
- Determination by UPLC-MS/MS of saccharides in "low lactose" dairy products consumed in PortugalPublication . Motta, Carla; Delgado, Inês; Jesus, Susana; Castanheira, IsabelDairy products constitute an important source of the vitamins, and minerals, especially calcium1. However, the saccharides (lactose and galactose) content in lactose-free dairy products became increasingly important because the presence of lactose can be meaningful to individuals with low production of lactase the enzyme responsible for the digestion of lactose into galactose and glucose. Nowadays, there is an increase of the techniques and methods to analyze the lactose content.
- Determination of Acrylamide in Portuguese Bread by UPLC-MS/MS: metrological and chemometric toolsPublication . Jesus, Susana; Delgado, Inês; Rego, Andreia; Brandão, Carlos; Santos, Rui G.; Bordado, João; Castanheira, IsabelAcrylamide (AA) is known for its potential health hazards and it is present in processed potatoes, coffee, and bread. Wheat is still the most important cereal for bread making, however, the interest in its substitution by other grains is growing due to the consumer demand for novels and healthy foods, like oat and rye flour. The aim of this study was to analyze the AA content of confectioned bread in fifty-four different pastries and make an association of acrylamide contents and the place of production to identify the quality of the flour used. There was a wide variability in AA levels among different breads and within different bread varieties. The median of AA values was 787 μg/kg for whole grain bread, 783 μg/kg for oat bread and 253 μg/kg in rye bread. With the cluster analysis, it was possible to conclude that besides the factors like baking temperature-time and fermentation time which affects AA formation in bread products, several other parameters such as the formulation, flour quality and the varieties of processing techniques, among others, play a crucial role in the AA formation.
- Effect of Rocha pear peel extracts added to wheat and rye bread formulations on acrylamide reduction and sensory quality maintenancePublication . Morgado, Cátia; Bernardo, Patrícia; Henriques, Inês; Jesus, Susana; Rego, Andreia; Delgado, Inês; Coelho, Inês; Castanheira, Isabel; Félix, Nelson; Fernandes, António; Guerra, Manuela; Brandão, CarlosPear peels are seen as potentially valuable for their low-cost beneficial components content such as polyphenols. These may reveal acrylamide (AA) mitigation effect and thus their application in a susceptible food matrix, such as bread, should be considered. Aiming to assess the AA reduction potential of Rocha pear peels in bread and the effects on its sensory quality, two types of bread highly consumed in Portugal - wheat (WB) and rye (RB) – were assayed with the extract of these by-products, in two forms aqueous [a] and dry [d]. Eight bread batches were produced (4 WB; 4 RB); each composed of one control sample and five replicates added with extract. The process included controlled fermentation, and cooking in a traditional oven (TO) and convection oven (CO). Hedonic evaluation was made to samples of each batch. Overall, slight differences were observed for WB and RB hedonic evaluation between the control sample and those with both extract forms. Lower scores were observed in both bread types baked in CO, with [d] comparing with the control; for bread with [a], oven influence varied; higher scores for WB in CO and for RB baked in TO, comparing with the control. Regarding AA reduction, the highest mitigation rate was accomplished by the [d] in WB cooked in a CO, 27.3%. However, for RB the best formulation was obtained with [d] in the TO, 19.2%. These results support the importance of selecting the best baking process according to the varieties of bread and AA reduction.
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