Ergosterol contents in mycorrhizal wild edible mushrooms: comparison by hierarchical cluster analysis

Sterols are important molecules of the unsaponifiable fraction in several matrices. In mushrooms, ergosterol, which is an important vitamin D2 precursor, is clearly the main sterol. Hierarchical cluster analysis (HCA) is an unsupervised learning method to standardized data, checking for similarities between sample groups. This method calculates the distances (or correlation) between all samples using a defined metric such as squared Euclidean distance or Chebychev distance. Hierarchical clustering is the most common approach in which clusters are formed sequentially. The most similar objects are first grouped, and these initial groups are merged according to their similarities. Eventually as the similarity decreases all subgroups are fused into a single cluster. Herein, ergosterol was quantified by high performance liquid chromatography, coupled with an ultraviolet detector, in some of the most appreciated mycorrhizal edible mushrooms (Amanita caesarea, Boletus edulis, Cantharellus cibarius, Lactarius deliciosus and Morchella esculenta). Considering fat content (percentage) and ergosterol contents in mg/g fat and mg/100 g of dry weight, two main groups were formed in the HCA: one aggregating A. caesarea and B. edulis and another constituted by C. cibarius, L. deliciosus and M. esculenta. These two groups derived from the higher contents presented by B. edulis and A. caesarea. The detected values indicate that mushrooms might act as a potential source of this vitamin D2 precursor, with special relevance for diets deprived of food products of animal origin.Foundation for Science and Technology (FCT, Portugal) and COMPETE/QREN/EU for the financial support of this work (research project PTDC/AGR-ALI/110062/2009) and to CIMO (strategic project PEst- OE/AGR/UI0690/2011). J.C.M. Barreira also thanks to FCT, POPH-QREN and FSE for his grant SFRH/BPD/72802/2010

Automatic structures for semigroup constructions

We survey results concerning automatic structures for semigroup constructions, providing references and describing the corresponding automatic structures. The constructions we consider are: free products, direct products, Rees matrix semigroups, Bruck-Reilly extensions and wreath products.Comment: 22 page

Antioxidant and bioactive compounds of two wild edible mushrooms from Northeast of Portugal: Boletus poliporus and Boletus regius

Free radicals are produced in the normal natural metabolism of aerobic cells, mostly in the form of reactive oxygen species (ROS). Maintenance of equilibrium between free radicals production and antioxidant defenses is an essential condition for normal organism functioning [1 ,2]. Although almost all organisms are equipped with antioxidant defense, the antioxidant supplements, or natural products containing bioactive compounds, may be used to help reduce oxidative damage to the human body (3]. Indeed, natural matrices with antioxidant activity, in particular mushrooms, are used to aid the endogenous protective system, increasing interest in the antioxidative role of functional foods or nutraceutical products (2]. The present study describes the antioxidant properties and bioactive compounds of wild edible mushrooms (Boletus porosporus and Boletus regius) collected in Northeast of Portugal (Bragança). The antioxidant properties were assessed through the evaluation of the reducing power, radical scavenging activity and lipid peroxidation inhibition of the samples. The individual profiles of organic acids and phenolic compounds were obtained by high performance liquid chromatography coupled to photodiode array detector (HPLC-POA) and the tocopherols were characterized by HPLC-fluorescence.The Boletus regius sample revealed the best results in all the antioxidant activity assays, with the highest reducing power, highest scavenging activity and highest lipid peroxidation inhibition. Phenolic acids and a related compound (cinnamic acid) were found in both studied species and B. regius revealed the highest content in total phenolic compounds (23.49 mg/1 00 g dw), mainly due to the presence of two possible flavonoids. The highest levels of total tocophero ls were found in B. regius (763.80 j.Jg/1 00 g dw). The highest content in quinic and oxalic acids were found in B. porosporus(1.93 and 0.34 g/1 00 g dw, respectively), while B. regius revealed the highest level of citric acid (3.32 g/1 00 g dw).The results suggest that species of wild mushrooms from Northeast Portugal are a potential source of antioxidants to be explored.FCT and COMPETE/QREN/EU: project PTOC/AGR-ALI/110062/2009, PEst-PTDC/AGRALI/110062/2009 CIMO strategic project and L B. grant (BPD/4609/2008

How to catch a Smurf? - Ageing and beyond... In vivo assessment of intestinal permeability in multiple model organisms

The Smurf Assay (SA) was initially developed in the model organism Drosophila melanogaster where a dramatic increase of intestinal permeability has been shown to occur during ageing. We have since validated the protocol in multiple other model organisms and have utilised the assay to further our understanding of ageing. The SA has now also been used by other labs to assess intestinal barrier permeability. The SA in itself is simple, however numerous small details can have considerable impact on its experimental validity and subsequent interpretation. Here, we provide detailed update on the SA technique and explain how to catch a Smurf while avoiding the most common experimental fallacie

Edible mycorrhizal mushrooms as sources of bioactive phenolic compounds.

Mushrooms are emerging as one of the most appreciated foods on a global basis. Besides their nutritional properties and unique organoleptic characteristics, mushrooms might act as functional foods in view of the medicinal properties of their bioactive compounds [1,2]. Those medicinal properties are often due the antioxidant activity of specific molecules such as phenolic compounds [3]. In the present work, five edible mycorrhizal mushoom species (Amanita caesarea, Cortinarius anomalus, Cortinarius violaceus, Lactarius volemus and Suillus luteus) from Northeast Portugal were studied for their phenolic compounds profile and composition. The analyses were performed by High Performance Liquid Chromatography coupled to Diode Array detection (HPLC-DAD). Phenolic acids (protocatechuic, p-hydroxybenzoic and p-coumaric acids) were the major phenolic compounds. Cortinarius anomalus presented the highest content in phenolic acids (8.70.4 mg/100 g dw), while Lactarius volemus revealed the minimal values (0.50.1 mg/100 g dw). Nevertheless, the profiles in phenolic acids were somehow similar, since p-hydroxybenzoic acid was the main compound in all the assayed species, except Suillus luteus, in which protocatechuic acid predominated. The obtained results suggest mycorrhizal mushrooms as suitable sources of natural healthy products to be included in our diet. This study is integrated in a research project intending to valorise the traditional native mycological flora of Northeast Portugal, of great interest for the economical development of this region

Inactivation of capsaicin-sensitive nerves reduces pulmonary remodeling in guinea pigs with chronic allergic pulmonary inflammation

Pulmonary remodeling is an important feature of asthma physiopathology that can contribute to irreversible changes in lung function. Although neurokinins influence lung inflammation, their exact role in the extracellular matrix (ECM) remodeling remains to be determined. Our objective was to investigate whether inactivation of capsaicin-sensitive nerves modulates pulmonary ECM remodeling in animals with chronic lung inflammation. After 14 days of capsaicin (50 mg/kg, sc) or vehicle administration, male Hartley guinea pigs weighing 250-300 g were submitted to seven inhalations of increasing doses of ovalbumin (1, 2.5, and 5 mg/mL) or saline for 4 weeks. Seventy-two hours after the seventh inhalation, animals were anesthetized and mechanically ventilated and the lung mechanics and collagen and elastic fiber content in the airways, vessels and lung parenchyma were evaluated. Ovalbumin-exposed animals presented increasing collagen and elastic fiber content, respectively, in the airways (9.2 ± 0.9; 13.8 ± 1.2), vessels (19.8 ± 0.8; 13.4 ± 0.5) and lung parenchyma (9.2 ± 0.9; 13.8 ± 1.2) compared to control (P < 0.05). Capsaicin treatment reduced collagen and elastic fibers, respectively, in airways (1.7 ± 1.1; 7.9 ± 1.5), vessels (2.8 ± 1.1; 4.4 ± 1.1) and lung tissue (2.8 ± 1.1; 4.4 ± 1.1) of ovalbumin-exposed animals (P < 0.05). These findings were positively correlated with lung mechanical responses to antigenic challenge (P < 0.05). In conclusion, inactivation of capsaicin-sensitive nerve fibers reduces pulmonary remodeling, particularly collagen and elastic fibers, which contributes to the attenuation of pulmonary functional parameters

Combined effects of electron-beam irradiation and storage time on the chemical and antioxidant parameters of wild Macrolepiota procera dried samples

Mushrooms are very perishable foods due to their high susceptibility to moisture loss, changes in color and texture, or microbiological spoilage. Drying is considered as the most appropriate method to prevent these alterations, but it has some limitations, such as shrinkage, enzymatic and nonenzymatic browning reactions, and oxidation of lipids and vitamins. According to previous studies, irradiation might effectively attenuate the undesirable changes caused by drying process, ensuring also higher shelf-life of mushrooms and their decontamination. Electron-beam irradiation presents some technological advantages, since it allows higher dose rates and the possibility to be used in most foods/or thin products in a short period. Herein, the combined effects of electron-beam irradiation (0, 0.5, 1 and 6 kGy) and storage time (0, 6 and 12 months) were evaluated by measuring changes in nutritional parameters, namely, free sugars, tocopherols, fatty acids and antioxidant activity. As indicated by linear discriminant analysis, storage time had a higher effect on all the evaluated parameters, except fatty acids, which suffer significant changes with both factors. Overall, the obtained results indicate that electronbeam irradiation might be considered as a suitable technique, allowing long-lasting conservation periods while reducing changes induced by drying treatment.Foundation for Science and Technology (FCT, Portugal) for financial support of research centres CIMO (PEst-OE/AGR/UI0690/2011) and REQUIMTE (PEst-C/EQB/LA0006/2011). Â. Fernandes, A.L. Antonio and J.C.M. Barreira thank FCT, POPH-QREN and FSE for their grants (SFRH/BD/76019/2011, SFRH/PROTEC/67398/2010 and SFRH/BPD/72802/2010, respectively). Prof. A. Chmielewski, General Director of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, for allowing e-beam irradiations

Efeito da radiação gama nas propriedades químicas de Boletus edulis Bull: Fr. silvestre

Boletus edulis Bull: Fr. (comumente designado níscaro) é um cogumelo comestível bastante apreciado pelas suas propriedades organoléticas e nutricionais. No entanto, a sua sazonalidade e perecibilidade causam algumas dificuldades na distribuição e comercialização desta espécie em fresco; as perdas associadas a este tipo de alimentos durante a comercialização podem chegar aos 40% (Lacroix & Ouattara, 2000). Tem havido muita investigação no sentido de encontrar tecnologias que garantam a preservação dos cogumelos, mantendo as suas propriedades organoléticas e nutricionais por mais tempo. A irradiação é reconhecida como um método seguro e eficaz para a preservação de alimentos, sendo utilizada mundialmente para aumentar o tempo de prateleira de produtos em fresco (p. ex. frutos, legumes, especiarias, leguminosas, carne ou frutos do mar) (Fernandes et al. 2012). Em particular, a irradiação gama foi já aplicada a algumas espécies de cogumelos cultivados (principalmente do género Agaricus, Lentinula e Pleurotus), tendo-se mostrado uma tecnologia de conservação interessante (Fernandes et al. 2012). No entanto, não existem praticamente estudos em espécies silvestres, que são, em regra, muito valorizadas comercialmente. Neste trabalho, apresentam-se os resultados de estudos de avaliação dos efeitos da radiação gama nas propriedades nutricionais de B. edulis silvestre, aplicando as doses de 1 e 2 kGy. A irradiação foi realizada num equipamento experimental com fontes de 60Co. Todos os resultados foram comparados com amostras não irradiadas (controlo). Foram determinados macronutrientes e o valor energético, bem como os perfis individuais em açúcares livres, ácidos gordos e tocoferóis utilizando técnicas cromatográficas (Fernandes et al. 2013). Nenhum dos parâmetros avaliados foi significativamente afetado relativamente ao controlo, o que indica que a irradiação gama, nas doses aplicadas neste trabalho, pode representar uma tecnologia de conservação adequada para os cogumelos

Combined effects of γ-irradiation and storage times on sugars composition of Lactarius deliciosus: comparison through linear discrimant analysis

The effects of gamma irradiation on Lactarius deliciosus (L. ex Fr.) S. F. Gray sugars were evaluated in samples submitted to different storage periods (0, 4 and 8 days) at 4 ºC. The irradiations were performed in a 60Co experimental equipment. Changes in sugars were determined by analyzing the results obtained by high performance liquid chromatography coupled to refraction index detection (HPLC-RI) through a 2-way analysis of variance and a linear discriminant analysis. Mannitol was by far the most abundant sugar in the analyzed samples. Regarding sugars profile, storage time proved to have higher influence than irradiation dose, mainly reflected in the decrease of fructose and mannitol in stored samples

Ferramenta quimiométrica para identificação de cogumelos irradiados

Introdução: A irradiação de alimentos tem sido utilizada para preservar diferentes matrizes, tomandose bastante apelativa para aplicação em cogumelos que sendo altamente perecíveis apresentam um reduzido tempo de prateleira. No entanto, toma-se imperativo desenvolver indicadores quimiométricos com a capacidade de distinguir alimentos irradiados de não irradiados. O perfil em triacilgliceróis (TAG) é específico de cada matriz natural e tem sido utilizado, por exemplo, para detetar adulterações de gorduras e óleos e como marcador químico taxonómico de cogumelos. Objetivo: O objetivo do presente trabalho foi avaliar o potencial da utilização do perfil em TAG como marcador para a deteção de alimentos irradiados, em particular, de cogumelos. Material e Métodos: Utitizaram-se corpos frutíferos silvestres de Boletus edulis Buli. provenientes de Trás-os-Montes, que foram divididos em dois grupos: o primeiro foi submetido a secagem (a 30°C em estufa) e o segundo foi mantido fresco (armazenado a 4°C no frígorffico). O grupo de amostras secas foi subdividido em quatro subgrupos, um controlo (não-irradiado) e os outros três submetidos a irradiação por feixe de eletrões (2, 6 e 10 kGy, respetivamente), realizada num irradiador de 10 MeV de energia. As amostras frescas foram subdivididas em três subgrupos, um controlo e dois submetidos a radiação gama (1 e 2 kGy, respetivamente), realizada numa câmara experimental com quatro fontes de Co-60. A análise dos TAG foi efetuada por cromatografja líquida de alta eficiência (HPLC) acoplada a um detetor evaporativo de espalhamento de luz (ELSD). Resultados e Discussão: As amostras frescas de B. edulis submetidas a irradiação gama apresentaram maiores percentagens de OLL e POL e menores de GOL, 000 e PPO, especialmente para a dose de 1 RGy. Quanto aos efeitos provocados pela irradiação por feixe de eletrões nas amostras secas, as doses de 6 e 10 kGy produziram alterações semelhantes: percentagens superiores de LLL e OLL e inferiores de OOL, 000 e PPO. As diferenças significativas encontradas entre os valores médios para cada TAG foram um bom indicador preliminar da sua capacidade para atuar como um indicador de irradiação. Conclusão: O perfil de triacilgliceróis pode ser uma ferramenta quimjométrica útil para detetar cogumelos irradiados, independentemente da espécie, forma de processamento ou fonte de irradiação, em especial quando se aplicam doses superiores a 1 kGy