Composição química da folha e do caule de Calamintha baetica

A área das plantas aromáticas e medicinais teve uma dinâmica de crescimento notável nos últimos anos incentivada pela procura de novos produtos bioativos mas também como fonte de nutrientes. O género Calamintha pertence à família Lamiaceae e em Portugal o seu uso está intrinsecamente associado às suas propriedades aromáticas, condimentares, ornamentais ou medicinais, tendo como exemplos a Salvia (salva), Ocimum (manjericão), Origanum (orégão), Mentha (hortelã), Romarinus (alecrim), Melissa (erva cidreira) e Calamintha (erva-das-azeitonas). A espécie da planta Calamintha baetica Boiss et Heldr encontra-se largamente distribuída pela região do Mediterrâneo e é considerada uma espécie pioneira colonizadora, principalmente de prados secos; de berma dos caminhos rurais, de terrenos selvagens na orla dos pinhais. As folhas produzem um aroma agradável, entre hortelã e orégãos, sendo muito apreciadas para temperos na cozinha e para fazer infusões. Em alguns lugares é usada para temperar azeitona e talvez por isso seja também conhecida por erva-das-azeitonas, mas também é designada por nêveda ou calaminta. Neste trabalho pretende-se caracterizar a folha e o caule da espécie C. baetica no que respeita à sua composição química. Para o efeito quantificaram-se os seguintes parâmetros: humidade, cinzas, gordura, proteínas, hidratos de carbono e valor energético e também se estudou o perfil em ácidos gordos por cromatografia gasosa acoplada a um detetor de ionização de chama (GC/FID). A amostra de folha de C. baetica revelou uma maior percentagem em proteína, com 11,81% (m.s.) e o caule em hidratos de carbono, com 20,54%. No que respeita a teores em gordura, a amostra de folha evidenciou valores ligeiramente superiores (3,30%, m.s.) aos do caule (1,13%, m.s.). A análise por cromatografia gasosa permitiu identificar três ácidos gordos maioritários (% relativas), entre os quais os polinsaturados α-linolénico, com 69,11% e 44,93% e o linoleico com 10,03% e 23,83% e ainda o saturado palmítico, com 11,55% e 17,09% para a amostra de folha e caule, respetivamente.

Chemical composition of Boletus pinophilus and Clitocybe subconnexa: preservation with gamma irradiation

The short shelf life of mushrooms is a barrier for their distribution and, therefore, there has been extensive research to find technologies that ensure the preservation of mushrooms, maintaining their organoleptic and nutritional properties (1]. Irradiation has proved its technological feasibility to be safely used in the reduction of food losses, being recognized by international organizations as a valid conservation alternative in extending shelflife of many foods. The aim of the present work was to validate the use of 2 kGy dose of gamma radiation to maintain chemical composition of wild mushrooms. Boletus pinophilus Pihit & Dermek and Clitocybe subconnexa Murrill wild samples were obtained in Tnis-os-Montes; subsequently, the samples were divided in two groups: control (non-irradiated, 0 kGy) and irradiated (2 kGy). The irradiation of the samples was performed in a 6°Co experimental chamber. Moisture, protein, fat, carbohydrates and ash were determined following the standard procedures [2]. Free sugars and tocopherols were determined by high performance liquid chromatography coupled to a refraction index detector (HPLC-RI) and a fluorescence detector, respectively; fatty acids were determined by gas-liquid chromatography with flame ionization detection (GC-FID) [3]. The protein and ash content was preserved in both groups, although the sugars and tocopherols decreased in the irradiated samples. Sugars and fatty acids showed significant changes after irradiation treatment, particularly in B. pinophillus, nevertheless, the magnitude of the obtained differences did not seem to be sufficient to affect the chemical profiles of the assayed mushrooms. Overall, the detected chemical changes might be considered as allowable, in view of the high advantages offered by gamma irradiation at decontamination and/or disinfestation level.

Effects of electron-beam irradiation on chemical and antioxidation 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 non-enzymatic browning reactions, and oxidation of lipids and vitamins. Irradiation might effectively attenuate the undesirable changes caused by drying process, ensuring also higher shelf-life of mushrooms and their decontamination [I]. In the present work, the combined effects of electron-beam irradiation (at 0, 0.5, 1 and 6 kGy doses) and storage time (at 0, 6 and 12 months) were evaluated and compared. Macrolepiota procera (Scop.) Singer wild samples were obtained in Tnis-os-Montes, in the Northeast of Portugal, and dried at 30 •c in an oven. Subsequently, the samples were divided in four groups: control (non-irradiated, 0 kGy); sample 1 (0.5 kGy); sample 2 (1 kGy) and sample 3 (6 kGy). The irradiation was performed at the lNCTInstitute of Nuclear Chemistry and Technology (lNCT), in Warsaw, Poland. Moisture, protein, fat, carbohydrates and ash were determined following standard procedures. Free sugars and tocopherols were determined by high performance liquid chromatography coupled to a refraction index detector (HPLC-RI) and a fluorescence detector, respectively; fatty acids were determined by gas-liquid chromatography with flame ionization detection (GC-FID). Antioxidant activity was evaluated in the methanolic extracts by in vitro assays measuring DPPH (1,1-diphenyl-2- picrylhydrazyl) radical scavenging activity, reducing power, inhibition of ~-carotene bleaching and inhibition oflipid peroxidation using thiobarbituric acid reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. All the parameters showed a decrease tendency with storage time. Trehalose and y-tocopherol were preserved with 1 kGy dose. Electron-beam irradiation did not impart additional changes to most of the chemical and antioxidant parameters of M. procera dried samples. This is a very promising result, since electron-beam irradiation might attenuate most unwanted changes caused by drying, maintaining its long-term effectiveness.

Gamma radiation preserves chemical and bioactive properties of Boletus edulis wild mushrooms

Boletus edulis Bull: Fr. is an edible mushroom quite appreciated for its organoleptic and nutritional properties. However, the seasonality and perishability cause some difficulties in its distribution and marketing in fresh form; losses associated with this type of food during marketing can reach 40% [1]. Irradiation is recognized as a safe and effective method for food preservation, being used worldwide to increase shelf life of fresh and dehydrated products (e.g. fruits, vegetables and spices) [2]. In particular, gamma irradiation has already been applied to cultivated mushrooms (especially Agaricus, Lentinula and Pleurotus Genus) and proved to be an interesting conservation technology [3]. However, the studies with added-value wild species are scarce. In this work, the effects of gamma irradiation on chemical and antioxidant properties of wild B. edulis, were evaluated. Fruiting bodies were obtained in Trás-os-Montes, in the Northeast of Portugal, in November 2012. The irradiation was performed in experimental equipment with 60Co sources at 1 and 2 kGy. All the results were compared with nonirradiated samples (control). Macronutrients and energy value were determined following official procedures of food analysis; fatty acids were analyzed by gas-chromatography coupled to flame ionization detection (GC-FID), while sugars and tocopherols were determined by high performance liquid chromatography (HPLC) coupled to refraction index (RI) and fluorescence detectors, respectively. Antioxidant activity was evaluated in the methanolic extracts by in vitro assays measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of β- carotene bleaching and inhibition of lipid peroxidation using thiobarbituric acid reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. The nutritional profiles were not affected in high extension. Fatty acids and sugars were slightly affected, decreasing with the increasing doses. The performed assays for antioxidant activity, indicate that irradiated samples tended to have lower scavenging activity and reducing power, but higher lipid peroxidation inhibition. Despite the detected differences in individual compounds, the results of nutritional parameters, the most relevant in terms of mushroom acceptability by consumers, were less affected, indicating an interesting potential of gamma-irradiation to be used as an effective conservation technology for the studied mushrooms.

Chromatographic determination of fatty acids profiles in regionally-produced Portuguese goat cheese along curing

The biochemistry of cheese ripening involves mechanisms such as glycolysis, proteolysis and lipolysis. Fatty acids are released by the action of lipases from different sources, milk, rennet, bacteria, moulds included as secondary starters, and other exogenous lipases, during lipolysis [1]. The composition of the lipid fraction contributes positively to the flavour of cheese, for being precursors of more complex aroma compounds responsible for the characteristic “goaty flavour” of goat cheeses [2]. Goat milk is recognized by its easier digestibility, alkalinity, buffering capacity and certain therapeutic values in medicine and human nutrition [3]. A high total content of fatty acids is strongly linked to a rancid and tart off flavour in goat milk and may be considered undesirable in most cheese varieties [4]. In this sense, the purpose of the present study was to examine the composition and changes in fatty acids and saponification value of goat cheese during curing period (2, 7 and 12 months). Goat cheese was made in industrial unit of Cachão - Mirandela (Trás-os- Montes) with raw milk Serrana goats’ race, salt and rennet from animal origin. During the first two months, the samples were stored in a ripening chamber (9.5-11 °C and RH 75-85%). From the second month to one year, the samples were stored in a preservation chamber (10.5-12 °C and RH 75-85%). The fatty acids profile of the inner part of the cheese was analyzed by gas-chromatography coupled to flame ionization detection (GC-FID). The degree of saponification was determined both in the crust and inside the cheese by HCl titration of ethanol KOH solution of the samples. Twenty-six fatty acids (FA) were identified and quantified in the inner part of the cheese (total fat was 45-46 g/100 g during the curing period). Saturated fatty acids (SFA) did not change up to 7 months of curing, increasing only after 12 months, being palmitic (C16:0), stearic (C18:0), myristic (C14:0) and capric (C10:0) acids the most abundant FA in this class. Monounsaturated fatty acids (MUFA) decreased only after 12 months, and oleic acid (C18:1) was the predominant FA. In polyunsaturated fatty acids (PUFA) class, the most abundant were linoleic (C18:2) and linolenic (C18:3) acids, and followed the same tendency of MUFA. This is corroborated by an increase in the degree of saponification, either in the crust as in the inner part of the cheese, after 12 months of curing, probably related with the saturation of the fatty acids [3]. Extra-long curing can be done in cheeses produced with goat milk up to seven months of storage without changing the total fat and individual FA content.

Perfil cromatográfico de ácidos gordos e açúcares em requeijões funcionalizados com extratos de plantas livres e microencapsulados

Atualmente existe um grande interesse da indústria alimentar pela utilização de extratos e produtos naturais em substituição de aditivos sintéticos, por conterem ou serem substâncias biologicamente ativas, nomeadamente do ponto de vista antioxidante [1]. Alguns estudos anteriores da nossa equipa de investigação revelaram que a incorporação de extratos de Foeniculum vulgare Mill. (funcho) e Matricaria recutita L. (camomila) em amostras de requeijão, conferia-lhes propriedades antioxidantes, para além de manterem o seu valor nutricional [2;3]. No entanto, verificou-se que este efeito era limitado a 7 dias. Assim, para prolongar a referida bioatividade, os extratos aquosos das plantas mencionadas foram microencapsulados em matriz de alginato e, posteriormente, incorporados em requeijões. Os produtos finais foram analisados cromatograficamente em termos de ácidos gordos (GC-FID) e açúcares livres (HPLC-RI). As amostras de requeijão contendo os extratos microencapsulados e livres foram comparadas com os requeijões controlo (sem qualquer extrato). Os resultados obtidos revelaram que a incorporação dos extratos não provocou alterações nas características nutricionais dos requeijões. Em todas as amostras, os ácidos gordos predominantes foram os ácidos palmítico (C16:0) e oleico (C18:1). A ordem de abundância em ácidos gordos foi a seguinte: ácidos gordos saturados > ácidos gordos monoinsaturados >ácidos gordos polinsaturados. A lactose foi o único açúcar livre identificado e quantificado em todas as amostras. Adicionalmente, as amostras funcionalizados com extratos microencapsulados apresentaram maior preservação da atividade antioxidante após o sétimo dia.

Chromatographic methods to obtain the biomolecules profile of some aromatic plants irradiated with electron beam

Irradiation is being progressively considered as a versatile and effective conservation technique [1]. Based on this premise, our research group has been investigating the effects of different irradiation conditions in several food matrices. Aromatic plants are among the food products that require suitable conservation technologies to expand their use [2]. The effects of irradiation on the four species (Aloysia citrodora, Melissa officinalis, Melittis melissophyllum and Mentha piperita) studied herein were previously evaluated. In the present study, the same species were treated with different doses of electron-beam irradiation (0, 1 and 10 kGy) and several parameters were evaluated. The individual sugars profile was determined by HPLCRI, fatty acids by GC-FID, organic acids by HPLC-PDA and tocopherols by HPLCfluorescence. In general, the evaluated parameters remained practically unchanged, regardless of plant species or the irradiation dose. Regarding the profile of sugars, the major change was a decrease in the content of disaccharides. The most notable variations in organic acids were observed in plant species with the highest content in these molecules, especially the decrease observed in the samples of M. officinalis and M. melissophyllum. Among the tocopherols, the α and β isoforms were more susceptible to radiation, while the application of 1 kGy tended to increase the levels of tocopherols in Aloysia citrodora, while 10 kGy had the same effect on M. melissophyllum. M. piperita sample showed the highest levels of tocopherols, regardless of the dose applied. Finally, with regard to the fatty acids content, the irradiated samples showed higher percentages of monounsaturated fatty acids than the control samples. In general, analyzing the results taking into account the effects described, it can be concluded that the application of irradiation with electron beam at doses 1 and 10 kGy is an effective way to retain biomolecules profile of the studied species.

Aplicação de radiação gama a Ginkgo biloba L. e avaliação da sua composição química através de técnicas cromatográficas

A irradiação é uma técnica de conservação acreditada para ingredientes secos e representa quase 50% do mercado mundial relativamente à desinfestação póscolheita (~186 000 ton). Para além da sua aplicabilidade para conservação apresentase também, como uma solução adequada para o tratamento pós-colheita de plantas medicinais, a fim de garantir a sua descontaminação [1,2]. Neste estudo, foram avaliados os efeitos da radiação gama (1 e 10 kGy) na composição química de amostras de Ginkgo biloba L. desidratadas. Foram analisadas moléculas lipofílicas e hidrofílicas utilizando técnicas cromatográficas acopladas a diferentes detetores. Os açúcares livres foram analisados por HPLC-RI, os ácidos gordos por GC-FID, os ácidos orgânicos por HPLC-PDA e os tocoferois por HPLC-fluorescência. De acordo com os resultados obtidos foi evidente a preservação dos ácidos gordos, dos vitâmeros γ- e δ-tocoferol, da frutose, trealose e dos ácidos quínico e shikímico. Em particular, a dose de 1 kGy manteve o teor em α-tocoferol e em ácidos oxálico e málico, enquanto que a dose de 10 kGy diminuiu a concentração de α-tocoferol, glucose, sacarose e ácidos oxálico e málico. Deste modo e numa avaliação geral, 1 kGy seria a dose recomendada para manter o perfil químico relativo a estas moléculas no Gingko biloba L.

Chromatographic techniques to obtain the biomolecules profile of wild Suillus granulates

In recent years the interest in naturally occurring compounds has been increasing worldwide. Indeed, many of the bioactive compounds currently used as medicines have been synthesized based on the structure of natural compounds [1]. In order to obtain bioactive fractions and subsequently isolated compounds derived from natural matrices, several procedures have been carried out. One of these is to separate and assess the concentration of the active compound(s) present in the samples, a step in which the chromatographic techniques stand out [2]. In the present work the mushroom Sui/Ius granulatus (L.) Roussel was chemically characterized by chromatographic techniques coupled to different detectors, in order to evaluate the presence of nutritional and/or bioactive molecules. Some hydrophilic compounds, namely free sugars, were identified by high performance liquid chromatography coupled to a refraction index detector (HPLC-RI), and organic and phenolic acids were assessed by HPLC coupled to a photodiode array detector (HPLC-PDA). Regarding lipophilic compounds, fatty acids weredetermined by gas chromatography with a flame ionization detector (GC-FID) and tocopherols by HPLC-fluorescence detection. Mannitol and trehalose were the main free sugars detected. Different organic acids were also identified (i.e. oxalic, quinic and fumaric acids), as well as phenolic acids (i.e. gallic and p-hydroxybenzoic acids) and the related compound cinnamic acid. Mono- and polyunsaturated fatty acids were the prevailing fatty acids and a-, ~- and ~-tocopherol were the isoforms of vitamin E detected in the samples. Since this species proved to be a source of biologically active compounds, the antioxidant and antimicrobial properties were evaluated. The antioxidant activity was measured through the reducing power, free radical's scavenging activity and lipid peroxidation inhibition of its methanolic extract, and the antimicrobial activity was also tested in Gram positive and Gram negative bacteria and iri different fungi. S. granulatus presented antioxidant properties in all the performed assays, and proved to inhibit the growth of different bacterial and fungal strains. This study is a first step for classifying S. granulatus as a functional food, highlighting the potential of mushrooms as a source of nutraceutical and biologically active compounds.

Bioactivity and chromatographic analysis of nutrients and non-nutrients of two Leccinum species

Nowadays the rising cost of health care and pharmaceutical products, the increase in life expectancy as well as the demand for an improved quality of life, has led to an increased concern about food intake and an emergence of new concepts of nutrition [1]. Mushrooms have been pointed out as an excellent option to include in a healthy diet, due to their nutritional value [2] associated with their bioactive properties [3]. The current study presents the chemical profile of two edible species, Leccinum molle (Ban) Ban and Leccinum vulpinum Watling, harvested in the outskirts of Bragan9a (Northeastern Portugal), regarding their content in nutrients and nonnutrients. Individual profiles of sugars and fatty acids were obtained by HPLC-RI and GC-FID, respectively. Tocopherols were analysed by HPLC-fluorescence, and the non-nutrients (i.e., phenolic and other organic acids) by HPLC-PDA. The antioxidant activity of the methanolic extracts obtained from both species was assessed with different assays (e.g. reducing power, radical scavenging activity and lipid peroxidation inhibition) and their hepatotoxicity was evaluated in primary cell cultures obtained from porcine liver, PLP2. Generally, both Leccinum species revealed similar nutrient profiles, with low fat levels, fructose, mannitol and trehalose as the foremost free sugars, and higher percentages of mono- and polyunsaturated fatty acids in comparison with saturated fatty acids. The presence of bioactive compounds was also detected, namely phenolic (e.g., gallic, protocatechuic and p-hydroxybenzoic acids) and organic acids (e.g., citric and fumaric acids). Both species presented antioxidant properties, being L. vulpinum the species which showed the most promising results (higher contents of total phenolic acids and lower ECso values in all the performed assays). Neither of the extracts presented toxicity against the liver primary cells PLP2, up to maximal concentration tested (Giso > 400 μg/ml).

Influência da radiação por feixe de eletrões no perfil cromatográfico de Bauhinia variegata var candida: flor comestível proveniente do brasil

As flores de Bauhinia variegata var candida apresentam coloração branca e são vulgarmente conhecidas como “patas de vaca branca”, sendo muito utilizadas na cozinha gourmet como forma de aumentar a qualidade sensorial e nutricional dos alimentos [1,2]. 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 seguidamente analisadas em termos de parâmetros nutricionais (humidade, proteínas, gordura, hidratos de carbono e cinzas) e perfis em açúcares livres (HPLCRI), ácidos gordos (GC-FID), tocoferóis (HPLC-Fluorescência) e ácidos orgânicos (HPLC-DAD). As amostras não irradiadas e irradiadas mostraram um perfil nutricional semelhante, sendo os hidratos de carbono os nutrientes mais abundantes, seguidos das proteínas, gorduras e cinzas. Os perfis em açúcares foram também similares, estando presente a frutose em maior quantidade, seguida da glucose e da sacarose. Os ácidos mirístico (C14:0), palmítico (C16:0), esteárico (C18:0) e oleico (C18:1n9), foram os ácidos gordos mais abundantes. Os ácidos gordos saturados (SFA) foram os mais abundantes, seguidos dos mono (MUFA) e polinsaturados (PUFA). Neste caso, com maior dose de radiação verificou-se que a percentagem de SFA e MUFA diminui ligeiramente (principalmente pelo aumento dos ácidos esteárico e oleico, respetivamente), aumentando a percentagem de PUFA (principalmente pelo aumento dos ácidos linoleico e α-linolénico). No que respeita aos tocoferóis, só a isoforma α foi encontrada, apresentando aproximadamente o mesmo conteúdo nas amostras irradiadas e não irradiadas (1,75±0,06 mg/mL). O ácido cítrico foi o ácido orgânico mais abundante nas amostras, seguido dos ácidos: málico, ascórbico, oxálico e fumárico. Também neste caso os valores mantiveram-se, com exceção do ácido cítrico que aumentou ligeiramente com as doses de irradiação (55,94, 61,70 e 67,64 mg/mL, respetivamente). Em síntese, verificou-se que as doses de irradiação aplicadas não alteraram significativamente a composição química das amostras em estudo, e pode ser considerada uma técnica de descontaminação e preservação de flores comestíveis.

Frutos biológicos de Vaccinum myrtillus L. na base de novos produtos enriquecidos: caracterização química e nutricional

Vaccinum myrtillus L. pertence à família Ericaceae, sendo comumente conhecida pelos seus pequenos frutos e doces: os mirtilos. Largamente consumidos em fresco, estes frutos também são usados em compotas e marmeladas, devido à suas propriedades digestivas e hipoglicémicas bem como, devido à presença de vários compostos bioativos [1]. Portanto, tornou-se uma matriz muito apelativa para o desenvolvimento de novos produtos funcionais que, para além das suas propriedades nutricionais, adicionam um efeito benéfico fisiológico e para a saúde de longo prazo [2]. No presente trabalho, três novos produtos desenvolvidos pela RBR Foods Company (Portugal) tendo como base o mirtilo, foram caracterizados pelas suas propriedades nutricionais e químicas: hidratos de carbono, cinzas, proteínas, gordura e valor energético (seguindo métodos oficiais de análise de alimentos AOAC), perfil de ácidos gordos (por GC-FID), açúcares solúveis (por HPLC-RI), ácidos orgânicos (por HPLC-DAD) e tocoferóis (por HPLC de fluorescência). Os produtos resultam de uma mistura dos frutos com pétalas de rosa (P1), pétalas de calêndula (P2) e bagas goji e maçã (P3). Os frutos de mirtilo foram utilizados como amostra de controlo. O perfil nutricional dos novos produtos mostrou-se muito semelhante ao da amostra controlo: os hidratos de carbono foram os macronutrientes mais abundantes, seguido de proteínas e de gordura total. Em relação aos açúcares, frutose, glucose e sacarose foram identificados em todas as amostras. P1 e P2 não apresentaram diferenças significativas em relação ao controlo, no entanto, P3 revelou uma menor concentração de açúcares. Em termos de composição de ácidos gordos, todas as amostras estudadas apresentaram maiores teores em ácidos gordos polinsaturados, especialmente devido à contribuição dos ácidos linoléico e alfa-linolénico. Os resultados de tocoferóis revelaram que a amostra controlo apresentou apenas duas isoformas de tocoferóis, α- e γ-tocoferol, sendo a mesmo observado em P3. No entanto, P1 revelou a presença de todas as isoformas de tocoferóis, enquanto P2 não apresentaou δ-tocoferol; Estes resultados estão relacionados com a contribuição das pétalas de rosa e calêndula, respetivamente. A isoforma α-tocoferol foi a mais abundante em todas as amostras estudadas. Em geral, este trabalho contribuiu para a caracterização de novos produtos nutricionais com base de mirtilo sendo parte de um projecto mais abrangente que tem por objetivo o estudo detalhado destes produtos, para serem utilizados como alimentos funcionais.