Avelã: composição química e efeitos benéficos associados ao seu consumo

Among the different nuts grown worldwide, hazelnut (Corylus avellana L.) is considered one of the most popular and consumed. Hazelnut is mainly used by the food industry in chocolates, cakes and desserts, with only a small part of the world’s produc"on being consumed as table hazelnut. Hazelnut is considered to be a highly nutri"ous food, providing macronutrients (fat, protein and carbohydrates), micronutrients (vitamins and minerals) and several bioac"ve phytochemicals, including phenolic acids, flavonoids, tannins and phytosterols, among others. Despite presen"ng a high content in fat, hazelnut lipids mainly include monounsaturated fa$y acids (MUFA), which have been associated with beneficial health effects, par"cularly regarding the cardiovascular system. Moreover, different interes"ng proper"es, such as an"oxidant, an"-inflammatory, an"-prolifera"ve and hipocholesterolemic ac"vi"es have been ascribed to several micronutrients and phytochemicals present in hazelnuts. To date, some studies have shown that the consump"on of hazelnuts can have a beneficial effect on health, namely by reducing the risk of cardiovascular diseases. Therefore, its inclusion has been recommended as part of a healthy-diet.Os autores agradecem o financiamento da Fundação para a Ciência e a Tecnologia (FCT) através do projeto UID/ QUI/50006/2013 - POCI/01/0145/FEDER/007265 com apoio financeiro da FCT/MEC através de fundos nacionais e cofinanciamento FEDER.info:eu-repo/semantics/publishedVersio

Avaliação da autenticidade de Alheiras de caça por identificação específica de espécies

A produção de diferentes enchidos tradicionais é uma práti-ca enraizada em várias regiões do país, em particular no Nordeste Transmontano onde é produzido um produto mui-to apreciados por diversos consumidores, nomeadamente a alheira. A alheira é um produto cárneo tradicional, fumado e fermentado, cuja origem remonta ao final do século XV e se relaciona com a presença de comunidades Judaicas nesta região. Naquela data, sendo frequente o consumo de enchi-dos pela população Cristã e sendo o porco uma espécie não consumida pelos Judeus, para evitar serem facilmente iden-tificados pela Inquisição pelos seus diferentes hábitos ali-mentares, estes começaram a produzir um enchido com forma similar à da cozinha Cristã, mas usando carne de aves em vez de porco. A receita foi, eventualmente, passando através de gerações e tornou-se popular também entre os Cristãos, sendo atualmente produzida com base numa mis-tura de carne e gordura de porco, carne de aves, pão de trigo, azeite, alho, sal e especiarias [1]. Dado o seu sucesso, nos últimos anos, têm surgido novas versões deste tipo de enchido, entra as quais se destacam as alheiras de caça. Estas distinguem-se das suas congéneres tradicionais pelo facto de incluírem na sua composição carne de caça, a qual pode ser adicionada total ou parcialmente em relação à car-ne utilizada na sua confeção.info:eu-repo/semantics/publishedVersio

Phase transition in a mean-field model for sympatric speciation

We introduce an analytical model for population dynamics with intra-specific competition, mutation and assortative mating as basic ingredients. The set of equations that describes the time evolution of population size in a mean-field approximation may be decoupled. We find a phase transition leading to sympatric speciation as a parameter that quantifies competition strength is varied. This transition, previously found in a computational model, occurs to be of first order.Comment: accepted for Physica

Fragmentation Experiment and Model for Falling Mercury Drops

The experiment consists of counting and measuring the size of the many fragments observed after the fall of a mercury drop on the floor. The size distribution follows a power-law for large enough fragments. We address the question of a possible crossover to a second, different power-law for small enough fragments. Two series of experiments were performed. The first uses a traditional film photographic camera, and the picture is later treated on a computer in order to count the fragments and classify them according to their sizes. The second uses a modern digital camera. The first approach has the advantage of a better resolution for small fragment sizes. The second, although with a poorer size resolution, is more reliable concerning the counting of all fragments up to its resolution limit. Both together clearly indicate the real existence of the quoted crossover. The model treats the system microscopically during the tiny time interval when the initial drop collides with the floor. The drop is modelled by a connected cluster of Ising spins pointing up (mercury) surrounded by Ising spins pointing down (air). The Ising coupling which tends to keep the spins segregated represents the surface tension. Initially the cluster carries an extra energy equally shared among all its spins, corresponding to the coherent kinetic energy due to the fall. Each spin which touches the floor loses its extra energy transformed into a thermal, incoherent energy represented by a temperature used then to follow the dynamics through Monte Carlo simulations. Whenever a small piece becomes disconnected from the big cluster, it is considered a fragment, and counted. The results also indicate the existence of the quoted crossover in the fragment-size distribution.Comment: 6 pages, 3 figure

Critical Exponents for Nuclear Multifragmentation: dynamical lattice model

We present a dynamical and dissipative lattice model, designed to mimic nuclear multifragmentation. Monte-Carlo simulations with this model show clear signature of critical behaviour and reproduce experimentally observed correlations. In particular, using techniques devised for finite systems, we could obtain two of its critical exponents, whose values are in agreement with those of the universality class to which nuclear multifragmentation is supposed to belong.Comment: 10 pages, 3 figures, to be published in Nuclear Physics

Simulated emergence of cyclic sexual-asexual reproduction

Motivated by the cyclic pattern of reproductive regimes observed in some species of green flies (``{\it aphids}''), we simulate the evolution of a population enduring harsh seasonal conditions for survival. The reproductive regime of each female is also seasonal in principle and genetically acquired, and can mutate for each newborn with some small probability. The results show a sharp transition at a critical value of the survival probability in the winter, between a reproductive regime in the fall that is predominantly sexual, for low values of this probability, or asexual, for high values.Comment: 9 pages, 4 figures, requires RevTe

Avaliação nutricional e composição em ácidos gordos de 6 variedades de nozes, sementes de Juglans regia L., cultivadas em Trás-os-Montes

A dieta mediterrânea, considerada saudável e uma das melhores no que concerne à prevenção das doenças cardiovasculares inclui, como componentes importantes, os frutos secos. No entanto, e talvez devido ao facto deste tipo de alimentos ser rico em lípidos, assistiu-se a um declínio do seu consumo. Actualmente, associa-se o consumo de frutos secos à ingestão de ingredientes com propriedades funcionais. Quando comparadas com a maioria dos outros frutos secos, que contam principalmente ácidos gordos monoinsaturados, as nozes distinguem-se pelos teores elevados em ácidos gordos polinsaturados (omega-3 e omega-6)

Ammonia levels on in vitro degradation of fibrous carbohydrates from buffel grass

This study was carried out to examine the degradation dynamics of neutral detergent fibre (NDF) and the profile of volatile fatty acids that originate from the fermentation of buffel grass (Cenchrus ciliaris, L.) with various levels of ammonia in the growth medium. The treatments consisted of six levels of ammonia in the growth medium (0, 5, 10, 15, 20 and 30 mg/dL), which were obtained by adding urea. These in vitro incubation times were evaluated in three replicates per time for 0, 3, 6, 9, 12, 24, 36, 48, 72 and 96 hours. Rumen concentrations of acetate and propionate responded quadratically to the ammonia levels. The treatment with 15 mg/dL of ammonia nitrogen in the rumen fluid provided mean acetate and propionate contents of 57.6 mM and 23.1 mM, respectively. Urea addition elevated the degradation rate of potentially degradable fraction of NDF (pdNDF) from 2.5% to 20.1% in comparison with the treatment without urea and to a reduction in estimated discrete lag time from 0.34 to 2.31 hours. Urea supplementation increased the specific microorganism growth rate from 2.6% to 20.1%. At the end of the incubation trial, NDF degradation showed a quadratic response, with maximum value obtained at 17.76 mg/dL of ammonia in the rumen fluid. Urea improves the degradation dynamics of NDF from deferred buffel grass and increases the concentrations of acetate and propionate.Keywords: Cenchrus ciliaris, degradation kinetics, non-protein nitrogen, ure

Influência das culturas láticas no índice de proteólise do queijo minas frescal

Estudou-se, a influência de culturas láticas no índice de proteólise do queijo Minas Frescal, processado com leite não pasteurizado e pasteurizado. O emprego de culturas láticas na elaboração de queijo Minas Frescal pode ser indicado, uma vez que o índice de proteólise só se correlacionou com o tempo de conservação.The influence of lactic cultures in the ripening index of Minas Frescal cheese was studied, utilizing pasteurized and not pasteurized milk. The use of lactic cultures for Minas Frescal cheese can be recomended, since the ripening index had good correlation only with storage time

Classification PDO olive oils on the basis of their sterol composition by multivariate analysis

The sterol compositions (GLC/FID/capillary column) of monovarietal olive oils (51 samples) from the most important cultivars of northeastern Portugal (Cvs. Cobranc¸osa, Madural and Verdeal Transmontana) and 27 commercial samples of olive oils with protected denomination of origin (PDO) from the same region and cultivars were evaluated. Δ-sitosterol, Δ5-avenasterol and campesterol were the most representative sterols. Cholesterol, stigmasterol, clerosterol and Δ7-stigmastenol were also found in all samples. All studied samples respected EC Regulation N. 2568, and in all cases total sterols were remarkably higher than the minimum limit set by legislation, ranging from 2003 to 2682 mg/kg. Results were analysed with the help of several statistical techniques, including reduction of dimensionality by principal component analysis with cross-validation of the number of components, followed by the use of canonical variate predictive biplots for model development and canonical variate interpolative biplots for approximate classification of monovarietal and PDO olive oils. These biplots proved to be a very interesting solution in the present case study, overcoming the problems of interpretation and classification that arise whenever different multivariate analyses are coupled together