Cogumelos silvestres como fonte de moléculas bioactivas

No presente trabalho, apresentam-se estudos de avaliação das propriedades bioactivas e da composição nutricional de dezanove espécies de cogumelos silvestres provenientes de Portugal (Clitocybe alexandri, Cortinarius glaucopus, Fistulina hepatica, Hydnum repandum, Hygrophoropsis aurantiaca, Hypholoma capnoides, Laccaria amethystina, Laccaria laccata, Lactarius aurantiacus, Lactarius salmonicolor, Lepista inversa, Lepista sordida, Mycena rosea, Russula delica, Russula vesca, Suillus collinitus, Suillus mediterraneensis, Tricholoma sulphureum, Tricholoma imbricatum). A actividade antioxidante foi avaliada através de ensaios de determinação da capacidade bloqueadora de radicais livres, do poder redutor e da inibição da peroxidação lipídica em soluções de lipossomas. A composição das amostras em tocoferóis foi determinada por Cromatografia Líquida de Alta Eficiência (HPLC) acoplada a um detector de fluorescência. Os perfis em ácidos gordos e açúcares foram obtidos por cromatografia gasosa acoplada a um detector de ionização de chama (GC/FID) e por HPLC acoplada a um detector de índice de refracção (RID), respectivamente. As espécies analisadas mostraram ser fontes importantes de antioxidantes nomeadamente fenóis (0,51–7,90 mg/g) e tocoferóis (0,02–8,04 μg/g). β-tocoferol foi a forma encontrada em maiores quantidades enquanto que δ-tocoferol não foi detectado na maioria das amostras. Todas as espécies mostraram ter actividade antioxidante, sendo esta mais significativa para a amostra Hygrophoropsis aurantiaca (valores de EC50 inferiores a 1,35 mg/ml) devido à contribuição de fenóis (7,90 mg/g) e tocoferóis (1,94 μg/g). A determinação do perfil em macronutrientes demonstrou que os cogumelos silvestres são fontes ricas em proteínas (24,32-76,63 g/100 g) e glícidos (10,35-55,48 g/100 g), apresentando baixos valores de lípidos (0,36-2,63 g/100 g). A espécie que revelou maior valor energético foi H. aurantiaca. A análise da composição em ácidos gordos conduziu à quantificação de 25 moléculas. Predominaram os ácidos gordos insaturados, particularmente os ácidos oleico e linoleico (17-61% e 20-54%, respectivamente). A metodologia de análise de açúcares foi completamente validada no âmbito deste trabalho. Obteve-se um período de separação de 10 minutos e o método utilizado mostrou ser sensível, reprodutível e preciso. Arabinose (1,53-7,66 g/100 g), manitol (0,38-18,41 g/100 g) e trealose (0,21-18,66 g/100 g) foram os açúcares mais abundantes. Os estudos efectuados descrevem o potencial nutracêutico das espécies analisadas, disponibilizando informação que leve a uma melhor gestão e conservação dos macrofungos e respectivos habitats.The present study describes the bioactive properties and nutritional composition of nineteen wild mushrooms from Portugal (Clitocybe alexandri, Cortinarius glaucopus, Fistulina hepatica, Hydnum repandum, Hygrophoropsis aurantiaca, Hypholoma capnoides, Laccaria amethystina, Laccaria laccata, Lactarius aurantiacus, Lactarius salmonicolor, Lepista inversa, Lepista sordida, Mycena rosea, Russula delica, Russula vesca, Suillus collinitus, Suillus mediterraneensis, Tricholoma sulphureum, Tricholoma imbricatum). The antioxidant activity was evaluated through radical-scavenging capacity, reducing power and inhibition of lipid peroxidation in liposome solutions assays. Furthermore, the tocopherols composition was determined by high performance liquid chromatography (HPLC) coupled to a fluorescence detector. Fatty acid and sugar profiles were obtained by gas chromatography coupled to a flame ionization detector (GC/FID) and HPLC coupled to a refraction index detector (RID), respectively. The analysed mushrooms contain powerful antioxidants such as phenols (0.51– 7.90 mg/g) and tocopherols (0.02–8.04 μg/g). β-Tocopherol was the vitamer detected in higher amounts, while δ-tocopherol was not detected in the majority of the samples. All the species proved to have antioxidant activity being more significant for Hygrophoropsis aurantiaca (EC50 values lower than 1.35 mg/ml) due to the contribution of antioxidants such as phenols (7.90 mg/g) and tocopherols (1.94 μg/g). The macronutrient profile in general revealed that the wild mushrooms were rich sources of protein (24.32–76.63 g/100 g) and carbohydrates (10.35–55.48 g/100 g), and had low amounts of fat (0.36–2.63 g/100 g). The highest energetic contribution was guaranteed by H. aurantiaca. The analysis of fatty acid composition allowed the quantification of 25 fatty acids. Unsaturated fatty acids and, in particular, oleic and linoleic acids, were predominant (17–61% and 20–54%, respectively). Sugars methodology analysis was completely validated being all the compounds separated in a period of time of 10 min; the method proved to be sensitive, reproducible and accurate. Arabinose (1.53–7.66 g/100 g), mannitol (0.38–18.41 g/100 g) and trehalose (0.21– 18.66 g/ 100 g) were the most abundant sugars. The present study states the nutraceutical potential of the analysed species, making the information available for a better management and conservation of mushrooms and related habitats

Plants as a source of natural preservatives for food application

One of the main challenges of the food industry has been the substitution of artificial additives for natural ones. In a world increasingly demanding for healthy foods, functional products, clean labels etc., it is urgent to develop safer,healthier altematives to preserve foods. Nature has been a fascinating source of distinct classes of compounds (e.g. phenolics, organic acids), recognizedfor their bioactive properties, namely antioxidants and antimicrobials, two essential attributes to be considered a natural preservative, in addition of having low/no toxicityeffectFoundation for Science and Technology (FCT, Portugal) for financiai support through national funds FCTIMCTES (PIDDAC) to CIMO (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LAIP/0007/2021). S. Heleno and M. Carocho thank FCT for their individual employment program- contract (CEECIND/00831/2018, CEECIND/03040/2017), and L. Barros thanks to the national funding by FCT through the institutional scientific employment program-contract for her contract. European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of the projects GreenHealth (Norte-Ol-0145-FEDER-000042) and co-promotion R&D project Bi04Drinks (NORTE-01-0247-FEDER-113508)info:eu-repo/semantics/publishedVersio

Plant extracts as biocontrol agents against Aspergillus carbonarius growth and ochratoxin A production in grapes

Aspergillus carbonarius (Bainier) Thom. is an important pathogen and ochratoxin A (OTA) producer in grapes that can be controlled by adopting sustainable approaches. Here we evaluate the application of natural plant extracts as an alternative to synthetic fungicides to reduce OTA contamination and to prevent infection of grapes by two isolates of A. carbonarius. In a preliminary screening, natural extracts of chestnut flower, cistus, eucalyptus, fennel, and orange peel were evaluated for their antifungal and anti-mycotoxigenic efficiency in a grape-based medium at concentrations of 10 and 20 mg/mL. Cistus and orange peel extracts demonstrated the best anti- fungal activity at both concentrations. Although the eucalyptus extract demonstrated no significant effect on Aspergillus vegetative growth, it significantly reduced OTA by up to 85.75 % at 10 mg/mL compared to the control. Chestnut flower, cistus, eucalyptus, and orange peel extracts were then tested at the lowest concen- tration (10 mg/mL) for their antifungal activity in artificially inoculated grape berries. The cistus and orange peel extracts demonstrated the greatest antifungal activity and significantly reduced mold symptoms in grapes. Moreover, all tested natural extracts were able to reduce OTA content in grape berries (17.7 ± 8.3 % - 82.3 ± 3.85 % inhibition), although not always significantly. Eucalyptus extract was particularly efficient, inhibiting OTA production by both strains of A. carbonarius by up to >80 % with no effects on fungal growth. The use of natural eucalyptus extract represents a feasible strategy to reduce OTA formation without disrupting fungal growth, apparently maintaining the natural microbial balance, while cistus and orange peel extracts appear promising as inhibitors of A. carbonarius mycelial growth. Our findings suggest that plant extracts may be useful sources of bioactive chemicals for preventing A. carbonarius contamination and OTA production. Nonetheless, it will be necessary to evaluate their effect on the organoleptic properties of the grapes.This work was supported by the Foundation for Science and Tech- nology (FCT, Portugal) #1 under Grant from national funds FCT/MCTES (PIDDAC) to CIMO [number UIDB/00690/2020 and UIDP/00690/ 2020] and SusTEC [number LA/P/0007/2020]; the European Regional Development Fund (ERDF) through the Competitiveness and Interna- tionalization Operational Program (CIOP) #2 under Grant dedicated to the project “PreVineGrape - Development of a biofungicide to combat grapevine diseases [number POCI-01-0247-FEDER-049695].info:eu-repo/semantics/publishedVersio

Bioactive properties of Mentha spicata L. infusions: a comparison between standard and reserve lots

Mentha spicata L., commonly known as spearmint and belonging to the Lamiaceae family, is widely used as infusion due to its exquisite and outstanding flavour [1]. This medicinal and aromatic plant is also known for its antioxidant properties due to naturally occurring active compounds, such as phenolic compounds including flavonoids. [2] Recently, with the increased consumption of herbal infusions, several novel products are emerging and different lots with distinct compositions of the same plant are available for herbal infusions preparation [3]. As an outstanding example, the standard lots have evolved to "reserve lots", which are prepared from the apical leaves of the plant, presenting different compositions and sensorial characteristics. In the present study, the aim was to evaluate and compare the antioxidant activity as well as the bioactive compounds (phenolics and flavonoids) content of M. spicatae infusions prepared from standard and reserve lots, in order to understand the potential differences between both batches. The antioxidant activity was assessed by different assays (free radicals scavenging activity, reducing power, and lipid peroxidation inhibition), whereas total phenolics and flavonoids were estimated by colorimetric assays. The best results of antioxidant activity were achieved with the reserve lot that presented the lowest EC50o values in all the assays performed (152 to 336 μg/mL) in comparison to the standard lot (173 to 546 μg/mL). Both the infusions revealed higher potential in lipid peroxidation inhibition, in concentrations of 173 (standard tot) and 152 μg/mL (reserve lot), followed by reducing power (301 and 198 μg/mL, respectively) and free radicals scavenging activity (546 and 336 μg/mL). As expected from the antioxidant assays results, the amounts of total phenolics and flavonoids were higher in the reserve lot (2. 86 and 0. 378 mg GAE/mL, respectively) when compared to the standard lot (1. 83 and 0.268 mg GAE/mL), which is in accordance with the well-known bioactivity of these compounds. Thus, in our perspective, this study represents a major contribution of scientific information, allowing the consumer to understand the increased benefits of these new emerging tea products

Systematic evaluation of the antioxidant potential of different parts of Foeniculum vulgare Mill. from Portugal

Fennel (Foeniculum vulgare Mill.) is a widespread perennial umbeliferous (Apiaceae) herb, traditionally used for medicinal purposes and human consumption. It is highly recommended for diabetes, bronchitis and chronic coughs, and for the treatment of kidney stones; some of those chronic diseases are related to the production of radical species involved in the oxidative stress. Therefore, the antioxidant potential of this herb might explain some of their empirical uses in folk medicine. This is the first time that a systematic study on different parts of fennel is performed, in order to understand differences in the antioxidant potential of shoots, leaves, steams, and inflorescences, particularly related to their composition in antioxidant compounds such as vitamins (ascorbic acid and tocopherols) and phenolics. The shoots seems to have the highest radical-scavenging activity and lipid peroxidation inhibition capacity (EC50 values < 1.4 mg/ml), which is in agreement with the highest content in phenolics (65.85 ± 0.74 mg/g) and ascorbic acid (570.89 ± 0.01 lg/g) found in this part. The shoots also revealed high concentration of tocopherols (34.54 ± 1.28 lg/g) and were the only part with flavonoids

Efeitos da radiação por feixe de eletrões no valor nutricional de Bauhinia Variegata var cândida: flores comestíveis provenientes do Brasil

As flores comestíveis têm sido muito utilizadas nas artes culinárias, sendo uma tradição em todo o munto desde há muitos anos. São utilizadas várias formas, cores e sabores de flores comestfveis, com o objetivo de melhorar a qualidade sensória! e nutricional dos alimentos [1,2]. As flores de Bauhinia variegata L. são grandes e apresentam coloração rosa a lilás na variedade mais comum, ocorrendo ainda uma variedade de flores brancas, denominada B. variegata var Cândida. Estas flores são vulgarmente conhecidas como "pata de vaca branca", sendo comestíveis e muito utilizadas em saladas. No presente estudo, as flores foram submetidas a radiação por feixe de eletrões em diferentes doses (0.5 e 0.8 KGy) como forma de descontaminação, e analisadas em termos de parâmetros nutricionais nomeadamente, composição centesimal (humidade, proteínas, gordura, hidratos de carbono e cinzas) e perfil em açúcares livres (determinados por HPLC-RI) e em ácidos gordos (analisados por GC-FID). As amostras controlo (não irradiadas) e irradiadas apresentaram um perfil muito semelhante; os hidratos de carbono foram os nutrientes mais abundantes nas amostras, seguidos das proteínas, gorduras e cinzas. Os perfis em açúcares foram também similares, estando presentes a frutose em maior quantidade, seguida da gtucose e da sacarose. Os ácidos capróico (C6:0), caprílico (C8:0), cáprico (C10:0), láurico (C12:0), mirístico (C14:0), palmítico (C16:0), esteárico (C18:0) e oleico (C18:1n9) foram os ácidos gordos mais abundantes nas amostras em estudo. Os ácidos gordos saturados (SFA) foram majoritários, seguidos dos mono (MUFA) e potinsaturados (PUFA). No entanto, com maior dose de radiação a percentagem de SFA e MUFA diminui ligeiramente (principalmente ácidos esteárico e oleico, respetivamente), aumentando a percentagem de PUFA (principalmente pelo aumento dos ácidos linoleico e a-linolénico). Em suma, as doses de irradiação aplicadas não alteraram significativamente o valor nutricional das amostras em estudo, podendo ser considerada como técnica de descontaminação e preservação de flores comestíveis

Lamiaceae often used in Portuguese folk medicine as a source of powerful antioxidants: vitamins and phenolics

Three Lamiaceae often used in Portuguese folk medicine: Ground ivy (Glechoma hederaceae L.), oregano (Origanum vulgare subsp. virens (Hoffmanns. & Link) Ietswaart) and mastic thyme (Thymus mastichina L.), revealed to be good sources of powerful antioxidants such as vitamins (ascorbic acid and tocopherols) and phenolics. The HPLC methodology developed for tocopherols analysis proved to be, after validation assays, sensitive and accurate. Ground ivy showed the highest levels of vitamins: ascorbic acid (168 2 mg/g dry weight) and tocopherols (3692 57 mg/g dry weight). The phenolics extraction was optimized using mastic tyme, and different conditions (water and ethanol:water 50% v/v, 30 min at 25 C and boiling temperature; ethanol and methanol, 24 h at 25 C). The best methodology (25 C, 50 ml of methanol, 24 h) was further applied to the other Lamiaceae. Oregano proved to have the highest radical scavenging and lipid peroxidation inhibition capacity. Particularly, the very low EC50 value (0.01 mg/ml) obtained for TBARS inhibition in brain homogenates is very promising, considering that brain is highly sensitive to oxidative damage. Significantly negative linear correlations were observed between phenolics, including flavonoids, and antioxidant activity EC50 values of the three Lamiaceae

Saprotrophic and mycorrhizal will edible mushrooms from Portuguese mycoflora as a source of nutrients and nutraceuticals.

In many countries of central and Eastern Europe consumption of wild growing mushrooms has been preferred to eating of cultivated fungi. Nevertheless, the knowledge of the nutritional value of wild growing mushrooms is limited

The influence of electron beam radiation on the nutritional composition of edible flowers of Bauhinia variegata L. from Brazil

No presente estudo, flores de Bauhinia variegata L. foram submetidas a radiação por feixe de eletrões em diferentes doses (0,5 e 0,8 kGy) para efeitos de descontaminação e, seguidamente, analisadas em termos de parâmetros nutricionais: composição centesimal (humidade, proteínas, gordura, hidratos de carbono e cinza), perfil em açúcares livres (determinados por HPLC -RI) e em ácidos gordos (analisados por GC -FID) a fim de analisar a influência da radiação por feixe de eletrões nas propriedades nutricionais das amostras. O teor em cinza aumentou ligeiramente com o aumento da dose de irradiação assim como o teor em hidratos de carbono. O teor em proteínas diminuiu nas amostras irradiadas e o teor em gordura diminuiu nas amostras irradiadas a 0,5 KGy. O conteúdo em frutose, glucose e sacarose manteve -se sem alterações significativas, pelo que o teor em açúcares totais também não sofreu alterações. A percentagem de SFA e MUFA diminuiu com a dose de 0,8 kGy, contrariamente ao teor em PUFA que aumentou nas amostras irradiadas com 0,8 kGy. O processo de irradiação não afetou grandemente as características nutricionais, podendo ser útil na descontaminação de flores comestíveis.In the present study, flowers of Bauhinia variegata L. were submitted to electron beam radiation at different doses (0.5 and 0.8 kGy) for decontamination purposes and then analysed in terms of nutritional parameters: centesimal composition (moisture, proteins, fat, carbohydrates and ash), profile in free sugars (Determined by HPLC -RI) and fatty acids (analysed by GC -FID) in order to study the influence of electron -beam radiation on the nutritional properties of the flower samples. The ash content increased with the increasing in the irradiation dose as also the content in carbohydrates. The proteins content decreased in the irradiated samples and the fat content decreased in samples irradiated at 0.5 kGy. The fructose, glucose and sucrose contents were maintained without significant differences, thus causing no alteration in total sugars content. The percentage of SFA and MUFA decreased at 0.8 kGy, contrarly to the content in PUFA that increased with the dose of 0.8 kGy. The irradiation process did not greatly affect nutritional characteristics and could be useful in decontamination of edible flowers.À Fundação para a Ciência e a Tecnologia (FCT) pelo apoio financeiro ao CIMO (PEst -OE/AGR/ UI0690/2014) e Sandrina A. Heleno (SFRH/BPD/101413/2014). Este estudo está incluído no projeto bilateral CNPq -FCT, Portugal/Brasil 2014.info:eu-repo/semantics/publishedVersio

Antioxidant activity of Agaricus bisporus L. hexane and ethanol extracts obtained by Soxhlet and ultrasound-assisted extraction: the importance of the presence of ergosterol

Mushrooms are well known for their richness in bioactive molecules such as antioxidants. Phenolic compounds, in particular phenolic acids, have been the most widely studied molecules regarding these effects [1]. Nevertheless, other molecules present in mushrooms, such as ergosterol, can also display bioactive properties [2]. Although being this high-value molecule more associated with hypocholesterolemic, antimicrobial and anti-inflammatory effects [2], it is also relevant to screen other bioactivities, such as antioxidant activity, either of the pure molecule or of mycosterols' rich extracts containing it. Agaricus bisporus L. is the most consumed mushroom worldwide, being ergosterol the most abundant mycosterol in its sterol fraction (represents almost 90%) [3]. Herein, A. bisporus ethanol and hexane extracts were prepared by Soxhlet and ultrasound-assisted extraction (amplitude: 75%;sonication time: 15 min), and further evaluated for their antioxidant activity. The in vitro assays used were: i) 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH) assay, to evaluate the scavenging activity; and ii) ferricyanide Prussian blue assay, to evaluate the reducing power. The obtained extracts were characterized in terms of ergosterol content by HPLC-UV. The antioxidant activity of pure ergosterol was also assessed. The extracts obtained by Soxhlet showed higher antioxidant activity than the ones obtained by ultrassonication, which is in agreement with the higher leveis of ergosterol found in the flrst extracts (677 and 186 mg/100 g dw for ethanol and hexane extracts, respectively). Ethanol extracts revealed higher antioxidant activity than the hexane exfracts, which is also in agreement with the higher ergosterol content found in both samples (677 and 672 mg/100 g dw for Soxhlet and ultrassonication extracts, respectively). The pure ergosterol also showed antioxidant activity (e. g., DPPH ECso value = 0.46 mg/mL). Overall, the ethanol extract obtained by Soxhlet gave the highest DPPH scavenging activity (EC5o = 2.2 mg/mL) and reducing power (ECsa = 0.8 mg/mL), while the hexane extract obtained by ultrassonication revealed the lowest DPPH scavenging activity (ECso = 16.7 mg/mL) and reducing power (EC5o= 2.2 mg/mL)