24 research outputs found
Nutritional value and influence of the thermal processing on a traditional Portuguese fermented sausage (alheira)
Alheiras are a traditional, smoked, fermented meat sausage, produced in Portugal, with an undeniable cultural
and gastronomic legacy. In this study, we assessed the nutritional value of this product, as well as the influence
of different types of thermal processing. Alheiras from Mirandela were submitted to six different procedures:
microwave, skillet, oven, charcoal grill, electric fryer and electric grill. Protein, fat, carbohydrate, minerals,
NaCl, and cholesterol contents, as well as fatty acid profile were evaluated.
The results show that alheiras are not hypercaloric but an unbalanced foodstuff (high levels of proteins and
lipids) and the type of processing has a major impact on their nutritional value. Charcoal grill is the healthiest
option: less fat (12.5 g/100 g) and cholesterol (29.3 mg/100 g), corresponding to a lower caloric intake
(231.8 kcal, less 13% than the raw ones). Inversely, fried alheiras presented the worst nutritional profile,
with the highest levels of fat (18.1 g/100 g) and cholesterol (76.0 g/100 g)
Responses of <i>Mytilus galloprovincialis</i> in a Multi-Stressor Scenario: Effects of an Invasive Seaweed Exudate and Microplastic Pollution under Ocean Warming
Microplastic pollution, global warming, and invasive species are known threats to marine biota, but the impact of their simultaneous exposure is still not well understood. This study investigated whether the toxic effects posed by the invasive red seaweed Asparagopsis armata exudate (2%) to the mussel Mytilus galloprovincialis are amplified by a 96 h exposure to increased temperature (24 °C) and polyethylene microplastics (PE-MPs, 1 mg/L). Biochemical (neurotoxicity, energy metabolism, oxidative stress, and damage) and physiological (byssal thread production) responses were evaluated. The number of produced byssus greatly decreased under concomitant exposure to all stressors. The antioxidant defences were depleted in the gills of mussels exposed to temperature rises and PE-MPs, regardless of exudate exposure, preventing oxidative damage. Moreover, the heat shock protein content tended to decrease in all treatments relative to the control. The increased total glutathione in the mussels’ digestive gland exposed to 24 °C, exudate, and PE-MPs avoided oxidative damage. Neurotoxicity was observed in the same treatment. In contrast, the energy metabolism remained unaltered. In conclusion, depending on the endpoint, simultaneous exposure to A. armata exudate, PE-MPs, and warming does not necessarily mean an amplification of their single effects. Studies focusing on the impact of multiple stressors are imperative to better understand the underlying mechanisms of this chronic exposure
Cytogenetic characterization of Melipona rufiventris Lepeletier 1836 and Melipona mondury Smith 1863 (Hymenoptera, Apidae) by C banding and fluorochromes staining
The stingless bees Melipona rufiventris and M. mondury were analyzed cytogenetically by conventional staining with Giemsa, C-banding and sequential staining with the fluorochromes CMA3/DA/DAPI. Both species presented 2n = 18 and n = 9, except for one colony of M. rufiventris, in which some individuals had 2n = 19 due to the presence of a B chromosome. After Giemsa staining and C-banding the chromosomes appeared very condensed and presented a high heterochromatic content, making it difficult to localize the centromere and therefore to visualize the chromosomes morphology. The constitutive heterochromatin was located in interstitial chromosome regions covering most of the chromosomes extension and consisted mainly of AT, as shown by DAPI staining. The euchromatin was restricted to the chromosome extremities and was GC-rich, as evidenced by CMA3 staining. The B chromosome was CMA3-negative and DAPI-positive, a heterochromatic constitution similar to that of the A genome chromosomes
Periods of constant and falling-rate for infrared drying of carrot slices PerÃodos de secagem constante e decrescente de fatias de cenoura por infravermelho
The aim of this work was to study the infrared drying process of carrot slices and to determine coefficients related to the heat and mass transfer of the process. Fresh carrots were used, dried until constant weight in a dryer with infrared heating source. Different models were utilized to fit the experimental data of constant and falling drying rate periods. It was verified that the coefficients of heat and mass transfer, during the constant drying rate, significantly increased with temperature on rise. The Diffusion Approximation, Two Terms, Midili and Verna models satisfactory represented the falling period of drying rate of carrot slices. The effective diffusion coefficient increased with temperature and this relationship can be represented by the Arrhenius equation, obtaining activation energy to the drying process of 29.092 kJ mol-1.<br>Com este trabalho objetivou-se estudar o processo de secagem por infravermelho das fatias de cenoura e determinar alguns coeficientes referentes à transferência de calor e massa do processo. Utilizaram-se cenouras frescas, secadas até massa constante em um secador com fonte de aquecimento por infravermelho. Aos dados experimentais se ajustaram diferentes modelos para os perÃodos de taxa de secagem constante e decrescentes. Verificou-se que os coeficientes transferência de calor e massa, referentes ao perÃodo de secagem constante, aumentaram significativamente com o aumento da temperatura e que os modelos Aproximação da Difusão, Dois Termos, Midili e Verna representaram satisfatoriamente o perÃodo de secagem decrescente das fatias de cenoura. O coeficiente de difusão efetivo aumentou com a temperatura e esta relação pode ser representada pela Equação de Arrhenius, obtendo-se uma energia de ativação para o processo de secagem de 29,092 kJ mol-1