Browsing by Author "Rodrigues, Paula"
Now showing 1 - 10 of 189
Results Per Page
Sort Options
- Aflatoxigenic fungi and aflatoxins in Portuguese almondsPublication . Rodrigues, Paula; Venâncio, Armando; Lima, NelsonAflatoxin contamination of nuts is an increasing concern to the consumer’s health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this work was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested for their aflatoxigenic ability. Almond samples were tested for aflatoxin contamination by HPLC-fluorescence. In total, 352 fungi belonging to Aspergillus section Flavi were isolated from Portuguese almonds: 127 were identified as A. flavus (of which 28% produced aflatoxins B), 196 as typical or atypical A. parasiticus (all producing aflatoxins B and G), and 29 as A. tamarii (all non-aflatoxigenic). Aflatoxins were detected in only one sample at 4.97 µg/kg.
- Aflatoxin Contamination of Various Staple Foods from Angola and MozambiquePublication . Matusse, Cláudio; Lucamba, Zelda; Bila, João; Macuamule, Custódia; Sampaio, Ana; Afonso, Sandra; Venâncio, Armando; Rodrigues, PaulaAflatoxins constitute a significant risk in staple foods produced in African countries. This research aimed to analyze the total aflatoxin (AFT) contamination of various staple foods in Angola and Mozambique. A total of 233 samples of corn, peanuts, beans, rice, and cassava flour collected from farmers or local markets from the province of Cuanza Sul, Angola, and the provinces of Gaza and Inhambane, South Mozambique, were analyzed for the presence of AFT using the lateral flow strip method via AgraStrip® ProWATEX® (Romer). The results showed that, from all matrices, the highest incidence and level of AFT were found in corn produced in Mozambique, with medians ranging from 6.5 to 66.5 μg/kg, with the samples showing values as high as 9200 μg/kg. Levels higher than the maximum admissible levels recommended by the Codex Alimentarius Commission for cereals and pulses (15 μg/kg) were observed in up to 90% of the corn samples, depending on the province. Corn produced in Angola showed lower amounts of AFT, with medians ranging from 1.2 to 7.7 μg/kg. Considering the maximum admissible levels for AFT recommended by the European Commission and the Codex Alimentarius Commission for cereals and pulses, the level of AFT contamination in staple food produced and consumed in the studied provinces is high and constitutes a public health risk for the population. Therefore, risk mitigation strategies are urgently needed.
- Aflatoxin M1 in Europe between 1990-2018Publication . Vaz, Andreia; Mourão, Filipa; Costa, Patrícia; Rodrigues, Paula; Venâncio, ArmandoAflatoxin M1 (AFM1) is a carcinogen metabolite that can be present in milk from lactating animals that consume aflatoxin B1 (AFB1) contaminated feed. AFM1, in addition to being hepatotoxic and causing carcinogenic effects, is relatively stable during milk pasteurization, storage and processing of various dairy products, which makes it a potential food contaminant. Consumption of dairy products has expanded rapidly over the past decade and, given the toxicity of this compound, its presence in milk and milk products poses a high risk to the health of the consumer. The occurrence of AFM1 in milk has been reported in many studies and considering the impact of AFM1 on human health and the economy, it is extremely important to study and understand the occurrence of this toxin in different countries of Europe over the years (from 1990-2018). The objective of this work was to study the trend of the occurrence of AFM1 in dairy products, including milk, cheese, butter and yogurt. To achieve this objective, an extensive literature search was made, in the databases Science Direct, Web of Sciences, Scopus and B-on, on quantitative AFM1 data, to evaluate the possible correlation between AFM1 concentration and sampling year, different types of milk products, applied heat treatment, and animal species' influences. For the study of heat treatment and animal species, only milk samples were considered. Data from 106 papers (representing 65,901 samples) were extracted and analyzed using IBM SPSS Statistics 27.0 statistical software. Data collected did not present homogeneity of variance nor followed a normal distribution. The discussion is based Welch and Brown-Forsythe's methods, followed by post hoc Games-Howell to evaluate differences betweens groups. Regarding the AFM1 distribution over the years, three decades were analyzed, 1990’s (1990-1999), 2000’s (2000-2009), and 2010’s (2010-2018), and no significant differences were observed between the two last decades. On the other hand, it was observed a significant difference between the two last decades and the 1990´s decade, presenting the last decades the highest AFM1 levels. In what regards dairy products, milk and yogurt were statistically similar and were the groups with the lowest levels of AFM1. Contrarily, butter and cheese samples were statistically different, with butter samples presenting the highest AFM1 concentration, probably due to a mass concentration effect. Concerning animal species, significant differences were noticed between all species analyzed. Namely, cow milk samples were the samples presenting the highest AFM1 levels, while buffalo milk samples had the lowest AFM1 levels. Regarding heat treatment, no significant differences were observed between raw, pasteurized and UHT milk samples. This study revealed that the levels of AFM1 in the last two decades are higher than the 1990´s decade, and the concentration in butter and cheese samples is higher than in milk samples. Therefore, considering the importance of dairy products, special measures should be taken to protect feed from contamination with AFB1, since the final levels of AFM1 will depend on the initial levels at the primary production.
- After COVID-19 lockdown: an exploratory study about the influence of mindfulness-feelings toward an individual’s outdoor lifestyle and empowermentPublication . Borges, Ana Pinto; Vieira, Elvira Pacheco; Rodrigues, Paula; Almeida, António Lopes de; Sousa, AnaThis study aimed to detect the relationships between mindfulness and events participation, and then between the later and psychological empowerment. Design/methodology/approach – The proposed model’s underlying hypotheses were empirically tested with data collected through an online survey addressed to a convenience sample of frequent leisure participants (n 5 199). The authors applied the structural equation model (SEM) to confirm the aforementioned relationships. To assess the adequacy of the psychometric properties of the measures, the authors performed a confirmatory factor analysis of the measurement model, with a maximum likelihood estimation method. Findings – Under the effects of the lockdown period environment, the results express a positive relationship between a mindful state of mind – related to observation/attention – and the yearnings and perceptions about the participation in events. This relationship for consistency was proven to be moderated by the perception of the participation importance to the individual subjective well-being/mental health. Due to participation insights, there was a positive effect on psychological empowerment, supporting the relationship that had been hypothesized. Originality/value – The authors propose and test a new model that contributes to the theory and examines how mindfulness behavior can effect more alluring and intense participation in events and what are the anticipated outcomes in terms of psychological empowerment.
- Agentes biológicos no combate das podridões da castanhaPublication . Agostini, Isadora; Silva, Sofia; Dallemole-Giaretta, Rosangela; Gomes-Laranjo, José; Sampaio, Ana; Rodrigues, PaulaApós a colheita da castanha (Castanea sativa Mill.), a maior preocupação das unidades de processamento é o controlo de agentes de deterioração, incluindo podridões. Atualmente, o fungo Gnomoniopsis smithogilvyi, agente causal da podridão castanha, tornou-se o principal causador de perdas de castanha em toda a Europa. Os objetivos deste trabalho foram: i) Analisar in vitro a atividade de um fungicida biológico comercial e de bactérias isoladas em laboratório no controlo dos agentes causais das podridões da castanha, em particular G. smithogilvyi; ii) Identificar a(s) bactéria(s) com potencial de controlo; iii) Estudar o modo de ação dos agentes selecionados contra G. smithogilvyi. Para tal, foram testados como potenciais agentes de controlo os produtos comerciais Serenade® ASO (Bacillus amyloliquefaciens) e Codasil® (solução de silício), e três isolados bacterianos. Como controlo positivo foi usado o fungicida Horizon® (Tebuconazol). Verificou-se que Serenade® ASO, Horizon® e a bactéria BCA1 tiveram efeito de controlo contra G. smithogilvyi, Trichoderma viridescens, Penicillium brevicompactum, Penicillium expansum, Mucor racemous e Ciboria batschiana. Codasil® estimulou o crescimento dos fungos. A bactéria BCA1 foi selecionada como potencial agente de biocontrolo, e foi identificada por métodos moleculares como B. amyloloquefaciens. Estudos sobre o modo de ação de Serenade® ASO e da bactéria BCA1 estão em curso.
- Agentes de biocontrolo contra as podridões da castanha no pós-colheitaPublication . Silva, Sofia; Agostini, Isadora; Pontes, Luirícia; Ramalhosa, Elsa; Gouveia, Maria Eugénia; Rodrigues, PaulaA castanha é um fruto de grande importância económica em Portugal. Após a colheita, uma das maiores preocupações das unidades de processamento é o controlo das podridões. A podridão castanha, causada por Gnomoniopsis smithogilvyi, e as podridões verdes/azuis, causadas por Penicillium sp., são as principais causas de perda de castanha pós-colheita. A termo-hidroterapia (banho quente) é o método mais utilizado na póscolheita para reduzir perdas mas, além dos custos elevados, não tem demonstrado eficácia suficiente. Este trabalho pretendeu encontrar soluções eficazes no controlo das podridões através de banhos frios adicionados de agentes biológicos. Foram efetuados 3 tratamentos (em duplicado) com: i) produto comercial Serenade® ASO (Bacillus amyloliquefaciens QST713; Ba form.), a estirpe QST713 em cultura pura (Ba c.p.) e uma estirpe laboratorial de B. amyloliquefaciens (BCA1). Como controlos foram usados banho-quente (48 ºC, 30 min) e banho frio (só água). As castanhas (n=10) foram submetidas a banhos de 3 horas e 3 dias (curatura), e foram avaliadas quanto à incidência (I) e severidade (S) das podridões após um mês a 4 ºC. Os valores de I variaram entre 50% (banho quente) e 100% (Ba c.p., 3 h), e os de S entre 34% (Ba form, 3 d) e 76% (Ba c.p., 3 h). Em comparação com o banho quente (controlo), os banhos de 3 d com Ba (form e c.p.) foram os que mostraram maior eficácia. Este ensaio preliminar indicia o potencial uso de B. amyloliquefaciens em banhos industriais de castanha.
- Agentes de biocontrolo contra as podridões da castanha no pós-colheitaPublication . Silva, Sofia; Agostini, Isadora; Pontes, Luirícia; Ramalhosa, Elsa; Gouveia, Maria Eugénia; Rodrigues, PaulaA castanha é um fruto de grande importância económica em Portugal. Após a colheita, uma das maiores preocupações das unidades de processamento é o controlo das podridões. A podridão castanha, causada por Gnomoniopsis smithogilvyi, e as podridões verdes/azuis, causadas por Penicillium sp., são as principais causas de perda de castanha pós-colheita. A termo-hidroterapia (banho quente) é o método mais utilizado na pós-colheita para reduzir perdas mas, além dos custos elevados, não tem demonstrado eficácia suficiente. Este trabalho pretendeu encontrar soluções eficazes no controlo das podridões através de banhos frios adicionados de agentes biológicos. Foram efetuados 3 tratamentos (em duplicado) com: i) produto comercial Serenade® ASO (Bacillus amyloliquefaciens QST713; Ba form.), a estirpe QST713 em cultura pura (Ba c.p.) e uma estirpe laboratorial de B. amyloliquefaciens (BCA1). Como controlos foram usados banho-quente (48 ºC, 30 min) e banho frio (só água). As castanhas (n=10) foram submetidas a banhos de 3 horas e 3 dias (curatura), e foram avaliadas quanto à incidência (I) e severidade (S) das podridões após um mês a 4 ºC. Os valores de I variaram entre 50% (banho quente) e 100% (Ba c.p., 3 h), e os de S entre 34% (Ba form, 3 d) e 76% (Ba c.p., 3 h). Em comparação com o banho quente (controlo), os banhos de 3 d com Ba (form e c.p.) foram os que mostraram maior eficácia. Este ensaio preliminar indicia o potencial uso de B. amyloliquefaciens em banhos industriais de castanha.
- An assessment of the processing and physicochemical factors contributing to the microbial contamination of salpicão, a naturally-fermented Portuguese sausagePublication . Cadavez, Vasco; Gonzales-Barron, Ursula; Pires, P.; Fernandes, E.; Pereira, Ana Paula; Gomes, Aline; Araújo, José Pedro; Lopes-da-Silva, M.F.; Rodrigues, Paula; Fernandes, Conceição; Saavedra, Maria José; Butler, Francis; Dias, TeresaComplete microbiological, physicochemical and environmental longitudinal data were obtained from factory surveys in order to elucidate risk factors leading to the survival of Enterobacteriaceae, Staphylococcus aureus and Listeria monocytogenes in salpicão sausage. A total of six batches were surveyed from two factories; one added nitrite and polyphosphates in their formulation (Factory II). The addition of polyphosphates slowed down fermentation, which favoured the increase in Enterobacteriaceae (∼0.5 log CFU/g), S. aureus (∼0.5 log CFU/g) and L. monocytogenes (∼70 CFU/g) until maceration. Maceration should be regarded as a critical stage in the control of S. aureus in salpicão, as longer maceration (p = 0.033), higher temperatures of maceration (p = 0.018) and pH of macerated meat (p = 0.079) led to higher S. aureus counts in the final product. The main hurdle controlling S. aureus in salpicão is the pH. For L. monocytogenes and Enterobacteriaceae, at least three hurdles hinder their viability: low Aw (p = 0.010; 0.012), smoking (p < 0.0001; 0.020) and nitrite (p = 0.158; 0.105). Cross-contamination, especially during mixing, should be avoided as it is an important factor explaining the increase in Enterobacteriaceae (p = 0.041), S. aureus (p = 0.015) and L. monocytogenes (p = 0.082) on a batch basis. There is a need to optimise the acidification process and reinforce good hygiene practices
- Anthocyanins from rubus fruticosus l. And morus nigra l. applied as food colorants: a natural alternativePublication . Vega, Erika N.; Molina, Adriana K.; Pereira, Carla; Dias, Maria Inês; Heleno, Sandrina A.; Rodrigues, Paula; Fernandes, Isabel P.; Barreiro, M.F.; Stojković, Dejan; Soković, Marina; Carocho, Márcio; Barreira, João C.M.; Ferreira, Isabel C.F.R.; Barros, LillianGiven the importance of colour in the general acceptance or rejection of a product, the use of colorants is a widespread practice, particularly in the food industry. At the same time, with the increasing consumers’ awareness of the health effects that some artificial colorants can exert, there is a growing tendency to prioritize foodstuffs containing natural additives. In this work, Morus nigra L. and Rubus fruticosus L. fruit juices were characterized in terms of anthocyanins, organic acids, free sugars, and tocopherols, as also regarding their bioactive properties. Given their richness in anthocyanins, this study also aimed to prepare different solid colouring formulations by the spray-drying technique, using as stabilizers maltodextrin and arabic gum. Six free sugars and two organic acids were detected in the fruit juices, as well as the four tocopherol isoforms. Two cyanidin derivatives were found in M. nigra (cyanidin-3-O-glucoside and cyanidin-O-rhamnoside) and other four in R. fruticosus (cyanidin-O-hexoside, cyanidin-3-O-glucoside, cyanidin-O-pentoside, and cyanidin-3-O-dioxaloilglucoside). The developed colouring formulations revealed a good stability over time, in terms of anthocyanin concentration and colour parameters, and revealed to be safe for consumption, either concerning their low microbial load and lack of cytotoxicity. Thus, they represent a promising natural alternative to the massively used artificial colorants.
- Aplicação de frutos de Lonicera caerulea L. var. Kamtschatica no desenvolvimento de corantes alimentares com propriedades bioativasPublication . Molina, Adriana K.; Corrêa, Rúbia C.G.; Pereira, Carla; Dias, Maria Inês; Heleno, Sandrina A.; Rodrigues, Paula; Kostić, Marina; Soković, Marina; Barreira, João C.M.; Barros, Lillian; Ferreira, Isabel C.F.R.Os frutos de Lonicera caerulea L. (haskap) são muito apreciados pelo seu sabor comummente descrito como uma combinação entre o mirtilo e a framboesa. Por serem ricos em ácido ascórbico, antocianinas e outros compostos bioativos, são muitas vezes considerados “super frutos” [1,2]. Com o presente estudo, pretendeu estudar-se a variedade Kamtschatica destes frutos em termos de valor nutricional (métodos AOAC), composição em açucares (HPLC-RI), ácidos orgânicos (UFLC-PDA), tocoferóis (HPLCfluorescência), ácidos gordos (GC-FID) e compostos fenólicos (HPLC-DAD/ESI-MS); bem como das suas propriedades bioativas (antioxidantes e antimicrobianas). Uma vez que apresentam elevadas concentrações de antocianinas, o objetivo foi também desenvolver formulações corantes líquidas e sólidas e avaliar a sua estabilidade ao longo de três meses de armazenamento, controlando as variações de cor, concentração de antocianinas, citotoxicidade e carga microbiana. Os frutos de haskap apresentaram um valor nutricional equilibrado, apresentando como macronutrientes maioritários os hidratos de carbono. Os açucares livres encontrados em concentrações mais elevadas foram a frutose e a glucose; detetaram-se duas isoformas de tocoferol (α e γ) e cinco ácidos orgânicos, com predominância do ácido cítrico. Relativamente aos ácidos gordos, observou-se uma clara prevalência de ácidos gordos polinsaturados, principalmente ácido linoleico. No extrato de haskap foram detetados dois compostos fenólicos não antociânicos, sendo o maioritário o ácido-3-cafeoilquínico, e seis antocianinas, com prevalência da cianidina-3-O-hexósido. O extrato revelou ainda uma forte atividade antioxidante e antimicrobiana. Relativamente às formulações corantes, de um modo geral, todas demonstraram também atividade antioxidante e antimicrobiana. Das formulações preparadas (três líquidas e duas sólidas), as sólidas revelaram uma maior estabilidade ao longo dos 3 meses de armazenamento, com variações menos acentuadas de cor e concentração de antocianinas. Em termos de segurança alimentar, estas revelaram também uma menor contaminação microbiana, sendo que nenhuma das formulações revelou citotoxicidade. Assim, este estudo permitiu obter uma extensa caracterização nutricional e química dos frutos desta variedade de haskap, bem como o desenvolvimento de corantes naturais estáveis com elevado potencial de aplicação na indústria alimentar.