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

Efeitos sinergistas da atividade antioxidante de cogumelos comestíveis: mistura de extratos fenólicos e polissacarídicos de Boletus edulis e Marasmius oreades.

Neste trabalho, avaliou-se a atividade antioxidante de diferentes misturas de Marasmius oreades e Boletus edulis (12,5/87,5, 25/75, 50/50, 75/25, 87,5/12,5) e comparou-se com os controlos (amostras individuais), com o objetivo de verificar qual das misturas contribui para efeitos sinergistas. As propriedades antioxidantes foram avaliadas por quatro métodos químicos e bioquímicos, sendo ainda determinados os fenóis totais (extratos fenólicos) e o teor em polissacáridos (extratos polissacarídicos). Foram observadas três tipos de interações utilizando as diferentes misturas de cogumelos: efeitos aditivos, sinergistas e antagonistas. Os resultados obtidos mostraram diferentes comportamentos nos ensaios de atividade antioxidante de acordo com as proporções utilizadas, indicando que as misturas de cogumelos permitem a ocorrência de diferentes interações químicas entre os compostos obtidos em cada espécie. Todas as diferentes proporções utilizadas de cada cogumelo demonstraram ter atividade antioxidante e, independentemente das proporções utilizadas, os extratos polissacarídicos apresentaram maior atividade antioxidante que os extratos fenólicos. Verificou-se também que a mesma mistura pode induzir um efeito sinergista num método de atividade antioxidante e um efeito antagonista noutro método de atividade antioxidante

Antioxidants in Pinus Pinaster roots and mycorrhizal fungi during the early steps of symbiosis

Ectomycorrhizal symbiosis between fungi mycelia and the roots of some plants could have important effects in the levels of antioxidants of both partners. In the present work, the effects of co-culture period in the antioxidant properties and antioxidants (phenolics, tocopherols and sugars) production during early steps of in vitro mycorrhization (Pinus pinaster-Pisolithus arhizus and Pinus pinaster-Paxillus involutus) were evaluated. The studied parameters were determined in each culture element (root, mycelium and medium) in order to understand the response of each partner to the symbiotic association. P. arhizus proved to be more compatible with P. pinaster than P. involutus, since the antioxidant activity in the latter species increased from 48 to 72 h, while P. arhizus antioxidant properties decreased at the same period (indicative of less oxidative stress). Despite P. involutus proved to be less suitable to be included in forestation programs using mycorrhization processes, it revealed a higher potential for bioactive compounds production in the early steps of symbiosis. A maximal value of phenolics content was obtained after the first 6 h

Insights in the antioxidant synergistic effects of combined edible mushrooms: phenolic and polysaccharidic extracts of Boletus edulis and Marasmius oreades

In a previous work, we reported the presence of Marasmius oreades in mixtures with antioxidant synergistic effects, and the mixture Boletus edulis and Marasmius oreades (50% of each) as having the highest antioxidant activity, but without synergism among the phenolic extracts. Herein, phenolic and polysaccharidic extracts from both species were combined in different proportions (12.5, 25, 50, 75 and 87.5%) and compared to controls (individual samples), in order to give insight in the contribution of each species to antioxidant synergistic effects. The antioxidant activity of the individual or combined extracts obtained from both edible mushrooms was evaluated through their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, -carotene bleaching inhibition and lipid peroxidation inhibition in brain homogenates using thiobarbituric acid reactive substances (TBARS) assay. Synergism was the main observed effect among the combined extracts, either phenolic or polysaccharidic. However, the effect of each B. edulis and M. oreades proportion was not the same for all antioxidant activity assays. In fact, the same mixture exhibited sometimes opposite behaviours according with the performed antioxidant activity assay

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

Evaluation of the chemical interactions in co-culture elements of Castanea sativa Miller mycorrhization

In the early steps of mycorrhizal associations an oxidative burst might occur through the rapid production of high amounts of reactive oxygen species in response to external stimuli, increasing the production of antioxidants in plant and/or mycelia. Herein, the effect of mycorrhizal association among Pisolithus arhizus or Paxillus involutus and Castanea sativa Miller (stems and roots) was studied for different co-culture periods, defined for a better comprehension of the chemical interactions in the early stages of mycorrhization (6, 24 and 72 h). Knowledge on the specificities of plant-host interaction provided information about the most suitable fungus to be included in the development of new management strategies, and the fungal species that induced the strongest response with increasing antioxidant activity (free radical scavenging activity, reducing power and lipid peroxidation inhibition) and production of antioxidant compounds (phenolics and tocopherols) and sugars. P. involutus seemed to be the most adequate fungus to mycorrhize with C. sativa. Considering bioactive compounds production, P. arhizus was more efficient since allowed an increase in the contents of sugars and tocopherols in all co-culture elements

Phenolic profile and antioxidant activity of Coleostephus myconis (L.) Rchb.f.: an underexploited and highly disseminated species

Coleostephus myconis (L.) Rchb.f. (Asteraceae) is a species with ruderal growth and persistence in abandoned soils, being characterized for its plentiful yellow flowering between March and August. Despite its botanical relevance, C. myconis had never been studied neither for its antioxidant activity, nor individual phenolic compounds. Herein, the antioxidant activity of different botanical parts: stems and leaves (green parts), floral buds, flowers in anthesis and senescent flowers, was studied in selected extracts (ethanol, ethanol:water 1:1 and water) through different chemical and biochemical assays. In addition, the phenolic profiles of the hydroethanolic extracts of each botanical part were also characterized by liquid chromatography with dioade array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI/MSn). The antioxidant activity was significantly modulated by the extract type, with the hydroethanolic extracts showing the highest antioxidant activity, especially those obtained from the senescent flowers and floral buds. The phenolic profiles were the same for all flowering stages (with quantitative differences), but that characterized in the green parts was quite different. Floral buds gave the highest contents in phenolic compounds, mainly due to the contribution of 3,5-O-dicaffeoylquinic acid and myricetin-O-methyl-hexoside. Overall, C. myconis showed an interesting potential to be included in different industrial applications.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), REQUIMTE (PEst-C/EQB/LA0006/2014), J.C.M. Barreira (SFRH/BPD/72802/2010) and L. Barros SFRH/BPD/107855/2015)

Gomphrena globosa L. as a novel source of food-grade betacyanins: Incorporation in ice-cream and comparison with beet-root extracts and commercial betalains

Currently, there are some examples of natural colourants with commercial use. However, these colourants are usually under-exploited, besides being obtained from a reduced number of plant or algal species. Accordingly, we propose using betalains obtained from an alternative plant species, Gomphrena globosa, which have a powerful colouring activity besides being strong antioxidants, as a novel ice-cream colourant. For comparison purposes, other ice-cream formulations were prepared, namely without colourants, added with commercial betalain or with Beta vulgaris extract. Besides evaluating the colour parameters L*, a* and b*, the nutritional parameters, individual sugars and fatty acids profiles were also studied. These parameters were evaluated throughout time, up to a maximum of 60 days of freeze (−22 °C) storage. Betacyanin quantification of each formulation was also performed to determine its maintenance along storage. In general, ice-creams prepared with G. globosa were similar (considering nutritional, colour, individual sugars and fatty acids profiles) to those including B. vulgaris extract, thereby validating the suitability of this alternative plant as a source of food colourants, particularly as ice-cream colourants. Furthermore, the positive effects induced by the addition of this natural colourant were maintained throughout storage time, as indicated by the markers distribution in the linear discriminant analysis.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013); L. Barros and J.C.M. Barreira contracts and C.L. Roriz grant (SFRH/BD/117995/ 2016). This work was also funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER- 023289: DeCodE and Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

Acorn flour and sourdough: an innovative combination to improve gluten free bread characteristics

Nowadays, challenges in gluten free breads (GFB) are focused on improving the nutritional and health benefits. Acorn flour is an underexploited sustainable ingredient, naturally gluten free, with many nutritional and technological advantages. The aim of this study was to explore the interaction of acorn flour supplementation (up to 35%) to rice flour and sourdough process to obtain rice based GFB. Different levels of rice flour replacement with acorn flour (0%, 23% and 35%), and sourdough (20%) were tested in a basic GFB recipe, and technological, nutritional, and functional GFB characteristics evaluated. The combination of acorn flour and sourdough was responsible for acidifying dough and bread. Breads containing 35:65 acorn flour: rice flour led to harder breads with lower crumb luminosity and with reddish and brownish tones, besides improved structural features when adding sourdough. That combination of sourdough and acorn flour reduced the rate and the extent of starch hydrolysis, as well as increase the minerals content, total phenolic compounds and antioxidant activity. Therefore, the combination of acorn flour and sourdough process allows obtaining rice based GFB with better nutritional patterninfo:eu-repo/semantics/publishedVersio

Improving the antioxidant activity of medicinal and aromatic plants by applying electron beam irradiation

Irradiation techniques have been applied for decontamination of aromatic and medicinal herbs. Their popularity in the pharmaceutical and food industry requires specific criteria in terms of microbiological safety [1, 2]. In this study the objective was to evaluate the effects of different doses of electron beam (EB) irradiation (0 kGy – control, 1 kGy and 10 kGy) on the antioxidant activity of Aloysia citrodora P., Melissa officinalis L., Melittis melissophyllum L. and Mentha piperita L.. The antioxidant properties of their infusions and methanolic extracts were evaluated through free radicals scavenging activity, reducing power and inhibition of lipid peroxidation in brain homogenates (TBARS assay). By comparing the results obtained from control and irradiated samples, it was evident that EB induced an increase in the ability to scavenge DPPH radicals and in the reducing power, independently of plant species and extract type. Nevertheless, a similar conclusion could not be performed for TBARS assay. In this case, the infusions from EB irradiated samples have also showed a higher effectiveness as lipid peroxidation inhibitors; however, some of the methanolic extracts (particularly those obtained from A. citrodora and M. piperita) did not allow an activity as high as the one observed in control samples. Even so, an increase in TBARS formation inhibition was also achieved in the methanolic extracts of M. melissophyllum and M. officinalis (this latter, only when a 10 kGy dose was applied). According to the described effects, it might be concluded that the application of EB irradiation is an effective way of increasing the antioxidant activity of the methanolic and aqueous extracts prepared from the assayed aromatic and medicinal plants.The authors are grateful to project PRODER nº 53514, AROMAP, for financial support of the work and E. Pereira grant, and to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2014), J.C.M. Barreira grant (BPD/72802/2010) and L. Barros “Compromisso para a Ciência 2008” contract. The authors are also grateful to “MaisErvas - Aromáticas e Medicinais” for samples providing and to Dr. A. Rafalski, for e-beam irradiations and Prof. A. Chmielewski, General Director of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, for allowing e-beam irradiations