Caracterização da fertilidade química de lameiros do nordeste transmontano

Os lameiros são pastagens de montanha, constituídos por vegetação espontânea ou sub-espontânea. Possuem uma importância secular na região do Nordeste Transmontano como suporte da alimentação dos efectivos pecuários. Com o objectivo de caracterizar o estado de fertilidade química destas pastagens procedeu-se à amostragem de solos em 7 lameiros, distribuídos pelo Nordeste Transmontano, na camada 0-30 cm. Os parâmetros químicos analisados foram: pH (H2O), matéria orgânica, azoto, fósforo, potássio e capacidade de troca catiónica efectiva (CTCe). Os valores de pH (H2O) variaram entre 5,1 e 6,3, valores ácido e pouco ácido, respectivamente; os teores de matéria orgânica variaram entre a classificação média (22,8 g kg-1) a alta (62,4 g kg-1); os valores de N situaram-se entre 1,4 e 2,8 g kg-1; o fósforo e o potássio variaram entre 12,4 a 68,5 mg kg-1 e 108,7 a 284,5 mg kg-1, respectivamente. À excepção do valor médio mais alto de fósforo registado, classificado de médio, os restantes são muito baixos e baixos. No que respeita ao potássio, registou-se apenas um lameiro com valor classificado de alto, sendo os restantes classificados de muito alto. Os valores de CTCe variaram entre 7,1 e 12 cmolc kg-1. Dois dos 7 lameiros possuem valores classificados de médios e os restantes têm valores baixos de CTCe. Os resultados obtidos apontam para um estado de fertilidade química dos lameiros, baixa a média, sendo previsível a necessidade de aplicação de adubos azotados e fosfatados

Evaluation of the practices applied in the preparation of vegetable salads in a catering unit

Food safety is nowadays an important issue for the consumers, being a point of great concern to catering units. These must prepare an equilibrated meal in terms of nutritional value and safety. The consumption of fruits and vegetables has assumed great importance. Nevertheless, in the processing of vegetables it is crucial to follow the basic rules of personal hygiene and making, as many times these products are served raw, without being subjected to any thermal processing. Even these catering units must follow European regulations and have implemented an HACCP plan, incorrect practices are sometimes observed. Thus, in the present work it was intended to evaluate the activities related with the preparation of vegetable salads in a catering unit. To achieve this goal, 21 periodic visits were performed and the survey of the activities linked to salad preparation was done by a check-list previously elaborated. In general terms, the practices followed in the reception, storage and preparation of the vegetables were quite satisfactory; however, some incorrect points were stated, such as the use of unrefrigerated vehicles by the vegetable supplier, the maintenance of the vegetables at room temperature during long periods of time and the incorrect application of the implemented Washing and Disinfection Plan, beyond other points. Moreover, variability on the disinfection method used in the vegetables salad preparation was also stated. In relation to personal hygiene of food operators, some points also need correction

Evaluation of soil organic carbon storage in a sustainable forest chestnut context

Soil organic carbon (SOC) is the major carbon (C) stock of the terrestrial biosphere with great importance for the balance of C at the global scale. So, a reliable estimate of the stored C in the mineral soil pool of forest ecosystems is of great importance. Inventory information on SOC stocks is very scattered, because of the inherent large spatial variability and the need of enormous sampling efforts. Therefore, traditional broadleaves species, less representative in the global context and scattered, as chestnut (Castanea sativa Mill.), are poorly sampled. Thus, this study was carried out to estimate the soil organic carbon (SOC) stock in traditional forests of sweet chestnut, based on in situ observations, to know the real contribution of this type of forests to the SOC stocks. This research was developed on old chestnut high forests for quality timber production submitted to a silviculture management close-to-nature located in Northern Portugal. At this stage the stands are close to self-thinning. Samples from soil profile at depths 0-10 cm, 10-30 cm and 30-60 cm were collected in 2002 and 2012. Besides the objective to know the real contribution of this type of forests to the SOC stocks, the evolution of the C storage was studied to also analyze the general capacity of the site concerning its sustainability and soil carbon pool. The cumulative amount of SOC shows an increase of 9% over 2002 in Marão and an increase of 4% in Bornes.info:eu-repo/semantics/publishedVersio

Comparação de métodos de amostragem de folhada: Implicações nas estimativas obtidas

A quantidade de folhada restituída anualmente aos ecossistemas e a sua decomposição são processos vitais para uma gestão sustentável uma vez que regulam o ciclo do carbono e de nutrientes no solo. A folhada é um importante reservatório de elementos minerais constituindo a principal via de restituição de nutrientes ao solo. É também, muitas vezes, o principal componente da produtividade primária líquida acima do solo como acontece nos povoamentos adultos de castanheiro bravo (Castanea sativa Mill,) em estudo. Contudo, a metodologia utilizada para a sua contabilização pode influenciar de forma significativa as estimativas obtidas em termos da biomassa produzida e do retorno dos potenciais nutrientes ao solo e da retenção do carbono. Diferenças metodológicas podem conduzir a discrepâncias significativas nas estimativas obtidas. Neste estudo comparam-se duas metodologias de contabilização da folhada restituída ao solo anualmente em 3 povoamentos adultos de castanheiro bravo de alto fuste localizados nas serras de Bornes, Marão e Padrela. Os métodos de amostragem utilizados foram o método da quadrícula (50 x 50 cm) e o método dos cestos circulares com uma área seccional de 1m2, sendo a colheita efetuada de forma aleatória. A colheita foi repetida durante dois anos consecutivos. A estimativa da quantidade de folhada obtida varia significativamente com o método utilizado não sendo significativa a interação método x local. O método da quadrícula apresenta estimativas da folhada significativamente mais elevadas com valores médios a variar entre 6,851 Mg ha-1 ano-1 no Marão e 8,514 Mg ha-1 ano-1 na Padrela enquanto que a folhada contabilizada com os cestos varia entre 4,499 Mg ha-1 ano-1 no Marão e 5,139 Mg ha-1 ano-1 na Padrela. Consequentemente, as estimativas do carbono e nutrientes restituídos ao ecossistema serão maiores ou menores dependendo do método utilizado

Knowledge, attitudes and practices evaluation on food hygiene and safety among perishable food handlers from a hypermarket in Portugal

The main objective of this study was to evaluate in loco the practices followed by the food handlers in three sections of a hypermarket, namely, butcher’s, charcuterie and fishery, as well as their level of knowledge, attitudes and practices in food hygiene and safety through the application of questionnaires. At the end it was also intended to relate the results with the training and professional experience, as well as demographic characteristics, such as sex, age and education level of food handlers. Regarding the in loco evaluation of the good personal hygiene and manufacturing practices followed by food handlers common failures were observed in the three sections studied, regarding clothing (incorrect placement of the cap and the use of adornments and jewelry), not frequent hand washing during peak flow of customers, use of cleaning and disinfecting products not indicated in the Hygienization Plan, and the use of textile fabrics. Concerning knowledge, attitudes and practices, in most situations no significant differences between the results obtained and the demographic characteristics of the food handlers were found. A high number of wrong answers were observed on topics related to microbiological knowledge and on some attitudes and hygiene practices. Therefore, these subjects should appear as priority issues in future training activities.Authors acknowledge CIMO through the Project PEst-OE/AGR/UI0690/2014info:eu-repo/semantics/publishedVersio

Chemical and thermal characterization of a portuguese traditional fermented meat sausage

In the North of Portugal several traditional fermented meat products are produced. One of these is the alheira that is a smoked sausage, made from the meat of pig, regional wheat bread and olive oil, seasoned with salt, garlic and paprika. This product must be subjected to a thermal process before consumption in order to garantee its safety and reducing the occurrence of foodborne diseases. The aim of the present work was to characterize this product in relation to the chemical composition and thermal behaviour. Alheiras were bought to local producers. pH, water activity, fat and protein contents were determined. In order to obtain the heating curves, alheiras were roasted at different temperatures, ranging from 120 to 240 ºC, in a forced convection oven. The center temperature, as well as the temperature of the sourrounding medium, were monitored along the heating. Alheiras presented a pH value of 6.07±0.26, a water activity of 0.92±0.01, a fat content of 6.60±0.68% and a protein content of 9.78±0.92. After a certain period of time, the temperature at the center of the product remained almost constant, around 100ºC, eventhough higher temperatures of heating were used. At 240 ºC the heating process was around three times faster than at 120ºC. For reaching 100 ºC, 13.0±0.5 min were necessary at 240 ºC instead 42.5±2.5 min at 120ºC

Evaluation of structural and functional conditions of regional Portuguese kitchens, their legal framing and influence on the quality of the final product

A region in Northeast of Portugal is known by its production of traditional meat products. Alheira is one of these products, being usually prepared in “Regional kitchens”. These are small units that cannot produce more than 2000 kg of dry sausages per year. Due to their regional importance, it was necessary to protect judicially the production of this kind of products. In fact, individual producers of regional kitchens have to follow European regulations, as well as a Portuguese normative, namely, the Law-Decree nº 209/2008 that approves the “State of Practice of the Industrial Activity” (REAI). In order to get knowledge about the effectiveness of this normative, in the present work the structural and functional conditions of three regional Portuguese kitchens were evaluated and is discussed how these points are considered in REAI. Moreover, the quality of the final product was also determined. The structural and functional conditions of the studied regional kitchens were adequate. Machines and local areas were appropriate and none crossing on production lines was observed. In relation to workers, their number was quite low (<3), with ages higher than 45 years old and low schooling. Most of these points are considered in REAI under the topic entitled “Descriptive Memory”. At last, it was verified that alheiras did not represent any danger to public health, as none food borne microorganisms were detected

Microbial population associated to the fermentation process of “Negrinha de Freixo” table olives produced in Portugal

“Negrinha de Freixo” is a typical table olive cultivar of the Northeastern region of Portugal, processed according to the natural fermentation methodology. Due to its distinctive characteristics, the “Negrinha de Freixo” table olives have been identified as Protected Designation of Origin (PDO). Despite its importance, no information about the microflora composition occurring in the fermentation process is available. The aim of the present study was to evaluate changes in some chemical characteristics and microbiological composition in brine during “Negrinha de Freixo” spontaneous fermentation. The microbial groups assessed by culture-dependent analysis were yeasts and lactic acid bacteria; and the chemical analysis included the measure of the pH and titratable acidity. The results indicate that yeasts were the main group of microorganisms involved during all fermentation process, but lactic acid bacteria (LAB) were also important in the second phase. Yeast and LAB populations ranged in 5.0-6.3 log cfu/ml and 2.3-5.8 log ufc/ml, respectively, during de fermentation. The final pH and the titratable acidity were 3.36 and 0.90 g of lactic acid/100ml, respectively. The yeasts population dynamics was showed to be significantly correlated with the pH and acidity values that occur during the fermentation process. The results obtained from this study could contribute to the improvement of fermentation processing, allowing the increase of their quality and simultaneously of their safety.This work was supported by project SUB-IOC-TEC 11/12 “Table olives from the Northeast of Portugal: Contribution for their characterization and promotion”. Authors acknowledge CIMO through the Project PEst-OE/AGR/UI0690/2014info:eu-repo/semantics/publishedVersio

Controlo microbiológico de pastas de azeitona processadas com diferentes especiarias e temperos

As pastas de azeitona são um produto apreciado e com procura crescente por parte do consumidor. No seu processamento diferentes aspetos deverão ser tidos em conta, sendo a segurança para o consumidor um dos mais importantes. Neste sentido, com o presente trabalho pretendeu-se avaliar a qualidade microbiológica de pastas de azeitona aromatizadas com diferentes especiarias e temperos (alho, azeite, louro, pimentão-doce, piripiri, orégãos e sumo de limão), elaboradas à escala laboratorial. Os microrganismos avaliados, após três meses de processamento das pastas, foram os mesófilos totais, bolores e leveduras, bactérias láticas, clostrídios sulfito redutores, Staphlylococcus aureus, coliformes totais, Escherichia coli e Salmonella spp.. Apenas na amostra de pasta de azeitona com adição de pimentão-doce foi possível contabilizar colónias viáveis de microrganismos, 2,3x103 UFC/g de mesófilos totais e 6,4x102 UFC/g de bactérias láticas. Apesar da presença destes microrganismos, os valores determinados indicam que o produto se encontra dentro dos limites de aceitabilidade estabelecidos pelos valores guia para avaliação da qualidade microbiológica de alimentos prontos a comer. Em nenhuma amostra analisada se detetou a presença de Salmonella spp.. Assim, todas as amostras analisadas revelaram qualidade microbiológica adequada, sendo por isso consideradas seguras para o consumidor. Estes resultados refletem a boa qualidade da matéria-prima inicial e mostram que as condições de higiene durante o processamento das mesmas e o tratamento térmico aplicado foram os adequados

Assessment of shade and nutrients addition effects on biomass of natural pastures of Northeast Portugal

Num lameiro onde ocorrem freixos espaçados entre si estudou-se, durante 2 anos, o efeito do sombreamento e da aplicação de fertilizantes na biomassa aérea e subterrânea da vegetação herbácea, bem como na respectiva composição química. Os tratamentos consistiram em: parcelas sob a copa das árvores com e sem aplicação de fertilizantes (CP+F, CP-F); parcelas fora da influência da copa das árvores cobertas com rede, de forma a reduzir a radiação para um nível semelhante ao verificado sob a copa, com e sem aplicação de fertilizantes (CC+F, CC-F); e parcelas fora da influência da copa sem cobertura de rede, sujeitas à radiação normal, com e sem aplicação de fertilizantes (SC+F, SC-F). O decréscimo da radiação foi obtido através de uma rede de sombreamento, que interceptava cerca de 65% da radiação incidente. A fertilização aumentou a produção de biomassa aérea de herbáceas em todos os tratamentos. A produção de biomassa aérea foi sempre mais baixa nas parcelas CP+F e CP-F em relação às parcelas CC+F, CC-F, SC+F e SC-F. A biomassa aérea das herbáceas das parcelas sombreadas artificialmente não diferiu significativamente em relação às parcelas sujeitas à radiação normal (SC+F e SC-F), mas diferiu em relação às parcelas CP+F. O teor de N, P, K, Ca, Mg e S da biomassa aérea e subterrânea de herbáceas foi de modo geral superior nas áreas sob a copa com aplicação de fertilizantes em relação às outras áreas consideradas. A biomassa radical total de herbáceas não diferiu significativamente entre os tratamentos. A razão entre biomassa aérea e subterrânea foi superior nos tratamentos com aplicação de fertilizante (0,37, 0,40 e 0,37 respectivamente em CC, CP e SC) em relação aos tratamentos sem aplicação de fertilizante (0,34, 0,28 e 0,25 respectivamente em CC, CP e SC)