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There is an increasing trend towards finding alternative sources of valued phytochemicals due to their diverse potentialities in food industry and pharmaceutical applications. Phenolic compounds, in particular, have been the focus of several profiling reports, but isoflavones characterization has been studied in fewer cases and in a very limited group of plant species. Despite their acknowledged bioactivity, there's actually a strict number of plants validated for their isoflavones contents. In a previous report, we have identified nine Leguminosae species (from genera Biserrula, Lotus, Ornithopus and Scorpiurus) as potential alternative sources of these phenolic compounds. However, the isoflavone profiles are highly modulated by the ontogenic stage. Therefore, the present study was conducted in the same Leguminosae species, but harvested at three sequential vegetative development stages: vegetative elongation, late bud and late flowering, with the main purpose of assessing the evolution of isoflavones content throughout the plant development. In general, the plant species from Biserrula and Lotus genera showed the highest potential as new natural sources of isoflavones, especially owing their high levels of biochanin A. Independently of the plant species, it was possible to identify the phenologic stages where each of the quantified isoflavones is maximized. These findings are useful to predict isoflavone yields according to harvesting time, validating the potential use of the studied plants in innovative food formulations. ; João C.M. Barreira and T. Visnevschi-Necrasov are grateful to "FCT - Fundação para a Ciência e a Tecnologia" for their grants (SFRH/BPD/72802/2010 and SFRH/BD/31734/2006, respectively) financed by POPH-QREN and subsidized by FSE and MCTES. This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT) through project Pest-C/EQB/LA0006/2013. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124 FEDER-000069. ; info:eu-repo/semantics/publishedVersion

Some studies have proven the antioxidant and antimicrobial potency of chestnut flowers both in the raw matrix and after extraction, and the consumption of their decoctions has been related to beneficial effects towards health. In recent years, due to controversy and ambiguous legislation of chemical conservatives, plant extracts have been successfully used as functionalizing agents in different matrixes, by displaying various beneficial effects towards the foodstuff and/or the consumer. In this manuscript, decoctions of chestnuts flowers as well as the dried flower were added to Portuguese traditional cakes that were then stored for 15 and 30 days, after which they were analysed for their antioxidant potential. The results were analysed by means of a 2 way ANOVA and a Linear Discriminant Analysis, concluding that storage time had a slightly higher influence in alteration of the antioxidant activity. DPPH and TBARS were the most improved parameters, regardless of the concentration added. ; The authors are grateful to M. Ferreira e Filhas Lda. (Pão de Gimonde) for the cakes recipe, and to the Foundation for Science and Technology (FCT, Portugal), for financial support to the CIMO research center (PEst-OE/AGR/UI0690/2011) and for J.C.M. Barreira's Post-Doctoral grant (BPD/72802/2010).

Most of the nearly 1500 species in Opuntia genus contain health-promoting components. These species are able to grow under adverse conditions, not suitable for other fruits/vegetables. Despite the acknowledge interest of their xoconostle fruits, especially due to their exquisite taste, other botanical parts from Opuntia are being scarcely studied. Herein, it was intended characterize Opuntia spp. seeds for their composition in soluble sugars, organic acids, tocopherols and phenolic compounds, besides evidencing their potential as sources of essential fatty acids. In addition, their antioxidant activity was assessed through different in vitro biochemical assays. Seeds of Opuntia spp. presented phytochemical profiles that allow their classification as a high-interest by-product. The levels of linoleic acid, γ-tocopherol and phenolic acids, as also their high antioxidant activity, are amongst the top characteristics that might endorse Opuntia spp. seeds in novel applications in food or pharmaceutical industries. ; The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). J.C.M. Barreira thanks FCT, POPH-QREN and FSE for his grant (SFRH/BPD/72802/2010). L. Barros thanks "Compromisso para a Ciência 2008" for her contract. The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063).

Chemical composition and antioxidant activity of Opuntia microdasys flowers in different maturity stages was evaluated. Fructose, glucose, sucrose and trehalose were found; oxalic, quinic, malic, and citric acids were also detected; five hydroxycinnamoyl, two kaempferol and six isorhamnetin derivatives; 23 fatty acids were quantified in all stages, except C20:2, which was only found in post flowering stage (F3); alpha-, beta-, gamma-, and delta-tocopherols were quantified in all samples. The highest contents in soluble sugars and phenolic compounds were detected in full flowering stage (F2), while organic acids and tocopherols were predominant in vegetative stage (F1). The highest levels of saturated, monounsaturated and polyunsaturated fatty acids were found in F3, F2 and F1, respectively. F1 gave the highest antioxidant activity. Principal components analysis showed clearly individualized groups corresponding to each flowering stage, identifying the most distinctive features, which might be useful to select a flowering stage for incorporation in functional foods. (C) 2014 ; Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011), João C.M. Barreira (SFRH/BPD/72802/2010 grant) and L. Barros ("Compromisso para a Ciência 2008" contract). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063).

Chestnuts are widely consumed around the world, especially in China, which is the major producer. Portugal is the fifth biggest producer, reaching and income of 17 M€, with particular relevance for Trás-os-Montes region, which is responsible for 81% of Portuguese production. During postharvest storage, a number of pests tend to attack chestnuts, contributing to high economic losses. Since 2010, the most effective postharvest treatment, i.e. fumigation with methyl bromide, was banned in the European Union, urging producers to seek effective and reasonable alternatives. One alternative could be irradiation with gamma rays or electron beam, which is used in food commodities, legally regulated and allows outstanding results. Our research group has tested both irradiation types in chestnuts and studied the nutritional, antioxidant and other chemical parameters, obtaining promising results. Herein, we extended these studies to selected cultivars from Portugal and Italy in order to validate this technique as a viable alternative to fumigation. The selected irradiation dose (1 kGy) was chosen following previous results where it proved to be effective without causing remarkable changes in chemical or antioxidant profiles. To obtain a global knowledge about how each cultivar reacts to irradiation, principal component analysis was performed using all the measured parameters. Despite the detected differences among cultivars, which differentiated particularly Palummina and Cota, it was verified that irradiation did not cause changes in chemical and antioxidant parameters that could enable defining distinctive features among irradiated and non-irradiated chestnuts. Hence, the results herein reported might be seen as a new step toward the completion of irradiation as feasible conservation technology, independently of chestnuts origin. ; The authors are thankful to ON.2/QREN/EU Project No.13198/2010, for financial support. A.L. Antonio and J.C.M. Barreira thank FCT, POPH-QREN, and FSE for their grants (SFRH/PROTEC/67398/2010 and SFRH/BPD/72802/2010, respectively). The authors also thank Prof. A. Chmielewski, General Director of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, for allowing electron beam irradiations.

Chestnuts are a widely consumed fruit around the world, being Portugal the fourth biggest producer in Europe. Storage of these nuts is an important step during processing, and the most widely used fumigant was banned in the European Union under the Montreal protocol due to its toxicity. Recently, radiation has been introduced as a cheap and clean conservation method. Previous studies of our research group proved that gamma radiation had no negative effect on the nutritional value of chestnuts; in fact, storage time had a much bigger influence on the chestnut quality. In the present study, we report the effect of a less ionizing radiation, electron beam, with doses of 0, 0.5, 1, 3 and 6 kGy in the nutritional value of chestnuts (ash, energy, fatty acids, sugars and tocopherols), previously stored at 4 ºC during 0, 30 and 60 days. The storage time seemed to reduce fat and energetic values but reported a tendency for higher values of dry matter. Regarding fatty acids, there was a higher detected quantity of C20:2 in non-irradiated samples, and four fatty acids were only detected in trace quantities (C6:0; C8:0; C10:0 and C12:0). γ-tocopherol decreased during storage time but did not alter its quantity for all the radiation doses (as like α-,β- and δ-tocopherol); in fact these compounds were present in higher concentration in the irradiated samples. Sucrose and total sugars were lower in non-irradiated samples and raffinose was only detected in irradiated samples. Electron beam irradiation seems to be a suitable methodology, since the effects on chemical and nutritional composition are very low, while storage time seems to be quite important in chestnut deterioration.

Edible flowers are used in food preparations, being also recognized for their beneficial effects on human health. Nevertheless, these species are highly perishable, and irradiation treatment might be applied to ensure food quality and increase their shelf life. Viola tricolor L. is a typical edible flower, with multiple applications and biological properties, mainly provided by the flavonoid content. In the present work, the phenolic compounds were analyzed by HPLC-DAD-ESI/MS, and the antioxidant activity was evaluated using biochemical assays. Linear discriminant analyses (LDA) were performed in order to compare the results obtained with flowers submitted to different irradiation doses and technologies (cobalt-60 and electron-beam). In general, irradiated samples (mostly with 1 kGy) showed the highest phenolic content and antioxidant activity. Furthermore, the significant differences observed in the LDA allow determination of which dose and/or technology is suitable to obtain flowers with higher antioxidant potential. ; The authors are grateful to the Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011), João C.M. Barreira (SFRH/BPD/72802/2010 grant) and L. Barros ("Compromisso para a Ciência 2008" contract). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). To CNEN, CAPES, CNPq and IPEN-CNEN/SP for financial support to Amanda Koike. This research is included in a Bilateral action FCT-CNPq, Portugal/Brazil 2014.

Plants are being increasingly used in dermatological formulations, since their collateral effects are lower than those caused by synthetic products. Hydrogels represent efficient formulations to incorporate plant extracts, providing good percutaneous absorption, non-greasy texture and easy application. Bryonia dioica Jacq. (white-bryony), Tamus communis L. (black-bryony) and Lonicera periclymenum L. (honeysuckle) fruits have important applications as topical homemade remedies. The phenolic extracts of B. dioica, T. communis and L. periclymenum were characterized by HPLC-DAD-ESI/MS, and further incorporated into hydrosoluble gels in order to evaluate their antioxidant potential. The hydrogels were prepared with each fruit extract at the EC50 value (obtained herein for each ethanolic extract). The antioxidant activity of extracts and hydrogels was evaluated following different chemical and biochemical assays. Eighteen compounds were identified in honeysuckle (7 flavonols, 7 hydroxycinnamoyl derivatives and 4 anthocyanins), fourteen in white-bryony (9 flavonols and 5 flavones) and twelve in black-bryony (7 flavonols and 5 flavones). Honeysuckle showed the highest concentrations of phenolic compounds, but the antioxidant activity was similar among the three assayed species. The obtained formulations revealed antioxidant activity close to 50% for reducing power, scavenging activity and β-carotene/linoleate assays. The studied fruits might be considered as good source of phenolic compounds that can be used in formulations for topical application, benefiting their antioxidant effects. ; Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). J.C.M. Barreira thanks to FCT, POPH-QREN and FSE for his grant (SFRH/BPD/72802/2010). M. Dueñas thanks to the Programa Ramón y Cajal for a contract. The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063).

In the region of Trás-os-Montes, chestnut production represents a significant income, estimated to be about 15 M€ in 2010. It is therefore, mandatory to develop a safe, reliable and cheap disinfestation alternative to post-harvest fumigation with methyl bromide, since its eradication in 2010 by the European Union, due to environmental concerns and danger for the operators. Hot water dip is being used as a replacement, but still display considerable technical disadvantages, giving way to other alternatives like irradiation. Today, many food commodities (e.g. frog legs, spices, mushrooms) are irradiated in Europe with strict regulation and no health issues reported [1]. Tocopherols represent the isoforms of vitamin E, which are known for their excellent antioxidant activity, either alone or in synergy with vitamin C. The natural antioxidants present in fruits help the body fight against dangerous free radicals, which lead to oxidative stress, and their intake should be favoured over food supplements [2]. The effects of gamma irradiation on the nutritional [3] and antioxidant [4] profiles of chestnuts has been studied by our research group as well as other chemical and physical parameters. Radiation has very low impact in both physic and chemical parameters when compared to other treatments and to the storage time that chestnuts are subject to. In this study, the validation of gamma radiation at 1 kGy was extended to 4 different varieties of chestnuts, 3 from Portugal (Longal, Judia, and Cota) and 1 from Italy (Palommina). The tocopherols profile of each variety of chestnuts was determined through High Performance Liquid Chromatography coupled to a Fluorescence Detector, demonstrating a very high concentration of γ- tocopherol when compared to α and δ, and no trace β-tocopherol. At this dosage, gamma radiation preserved these bioactive compounds in all the varieties, confirming its benefits as a treatment for chestnuts. ; ON.2/QREN/EU Project no.13198/2010 for financial support, FCT and COMPETE/QREN/EU for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). J.C.M. Barreira and A.L. Antonio also thank to FCT, POPH-QREN and FSE for their grants (SFRH/BPD/72802/2010 and SFRH/PROTEC/67398/2010, respectively).

The vast structural diversity of natural compounds found in plants provides unique opportunities for discovering new drugs. Anthocyanins are an example of bioactive compounds with possible beneficial effects on human health (/). Crataegus monogyna Jacq. (hawthorn) has been extensively studied due to its various alleged health benefits (2) . Herein, samples from fruits on three different maturity stages (unripe, ripened and over ripened fruits) were extracted with acidified (trifluoracetic acid) methanol. Extracts were purified on a C1s SepPak® Vac 3 cc cartridge (Phenomenex) and filtered through a 0.22-pm disposable LC filter disk. The HPLC system consisted of a 1-lewlett-Packard 1100 chromatograph (Agilent Technologies) with a quaternary pump and a diode array detector (DAD) coupled to an HP Chem Station (rev. A.05.04) data-processing. Double detection was carried out by DAD, using 520 nm as the preferred wavelength, and MS detection, performed in an API 3200 Qtrap (Applied Biosystems) equipped with an ESI source and a triple quadrupole-ion trap mass analyzer that was controlled by the Analyst 5.1 software. Further details were given by Rodrigues et al. (3). The anthocyanin profiles obtained for ripened and over ripened fruits were quite similar, consisting of five different compounds, whereas the profile in unripe fruits was simpler (only two anthocyanins). Cyanidin 3-0-glucoside, pelargonidin 3-0-glucoside and peonidin 3-0-glucos ide were positively identified by comparison with standards. The p1·esence of cyanidin 3-0-rutinoside and cyanidin pentoside was also confirmed by comparison of its chromatographic and UV and mass spectral characteristics with data in our library. Cyanidin-3-0-glucoside was the major anthocyanin in all the samples, and over ripened th1its were, by far, the phenological stage with the highest anthocyanin concentrations, which was coherent with its higher pigmentation. Accordingly, C. manogyna might be considered as a potential natural source of anthocyanins, whose bioactive properties might have several applications. ; FCT (Portugal) for financial support to 1he research centre CIMO (PEst-0E/AGR/UI0690/2011), J.C.M. Barreira grant (SFRH/BPD/72802/2010). Spanish Government for financial support to GIP-USAL through the Consolider-lngenio 2010 Programme (FUN-C-FOOD, CSD2007-00063); Programa Ramón y Cajal for M. Dueñas contract.

The substitution of artificial dyes by natural colouring agents is among the top concerns of food industry to fulfil current consuming trends, justifying the prospection of novel natural sources of these compounds. Herein, the hydrophilic extracts from rose, cornflower and dahlia were tested as potential substitutes to E163 (anthocyanin extract). Besides comparing the colouring capacity, the potential occurrence of changes in the chemical composition of yogurts (nutritional parameters, free sugars and fatty acids) was also assessed throughout storage (up to 7 days) and compared with a "blank" (free of any additive) yogurt formulation. In general, yogurts prepared with flower extracts, presented similar nutritional value and free sugars profile to those prepared with E163 and to the "blank" yogurt. Nevertheless, rose extract turned out to be the most suitable alternative to E163 as these two groups of yogurts had similar nutritional composition, free sugars and fatty acids composition, besides presenting close scores in colour parameters. ; The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (strategic project UID/AGR/00690/2013), to REQUIMTE (national funds and cofinanced by FEDER, under the Partnership Agreement PT2020), Tânia Pires (SFRH/BD/129551/2017) and João C.M. Barreira and L. Barros contracts. The GIP-USAL is financially supported by the Spanish Government through the project AGL2015-64522-C2-2-R. The authors are also grateful to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E; 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 Norte-01- 0247-FEDER-024479: ValorNatural®. ; info:eu-repo/semantics/publishedVersion

In spite of the immense popularity of mushrooms in the Northeast of Portugal, one of the European regions with higher wild edible mushrooms diversity, alternative technologies to increase mushrooms shelf-life are scarce. Treatment by irradiation emerges as a possible preservation technique, destroying microorganisms or insects that could be present in food and, sometimes, improving functional properties, with the least effects on sensory and nutritive quality (1). It has been successfully tested in several foods such as fruits, vegetables, meat, fish, aromatic and medicinal plants, being regulated by the European Union (EU) through the Directive (EC) No 1999/2/EC (2). In different countries (Croatia, Hungary, Poland, United Kingdom, Mexico) the recommended dose for extending the shelf life of fresh mushrooms is 1-3 kGy (3). Therefore, the aim of the present work was to validate the use of gamma irradiation at 2 kGy to maintain chemical parameters of wild mushrooms. The fruiting bodies of Boletus pinophilus Pilát & Dermek and Clitocybe subconnexa Murrill were collected in Trás-os-Montes (Northeast of Portugal) in November 2012 and 2013, respectively. The irradiation of these samples was carried out in experimental equipment with four 60Co sources. The estimated doses, dose rates and dose uniformity ratios (Dmax/Dmin) were: 2.09±0.16 kGy, 1.56 kGy/h, 1.18 for B. pinicola; and 1.95±0.22 kGy, 1.95 kGy/h, 1.33 and for C. subconnexa. The proximate composition was evaluated by official procedures, 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. Some of the analyzed chemical parameters (especially sugars and fatty acids) showed significant changes after irradiation treatment, particularly in B. pinophillus, probably due to its higher water content. Nevertheless, the obtained differences did not seem to be sufficient to change the organoleptic characteristics of these mushrooms. The detected chemical changes might be considered as acceptable, when considering the high advantages of gamma irradiation at decontamination and/or disinfestation level.

This study was designed to characterize the phenolic profile and evaluate the antibacterial, antimutagenic and antitumor activities of Veronica urticifolia Jacq. methanolic extract. HPLC-DAD/ESI-MS analysis revealed the presence of phenolic acids, flavonoids and phenylethanoids, with acteoside as the main component (14.9 mg/g of extract). Antibacterial effect was determined using the microbroth dilution assay and Staphylococcus aureus was the most sensitive strain (MIC and MBC = 7.5 mg/mL). Antimutagenic activity was evaluated by Ames mutagenicity assay. At 1 mg/plate, the tested extract afforded high protection against the mutagenicity of nitroquinoline-N-oxide (4NQO) to Salmonella typhimurium strain TA100 (inhibition rate 48.3%). Antitumor activity was screened in Ehrlich ascites carcinoma (EAC) model. Pretreatment with 2 mg/kg body weight showed statistically significant decrease in tumor cell viability, while ascites volume and tumor cell count became slightly decreased, but not to a statistically significant extent. Above results indicate that V. urticifolia deserves further research into chemoprevention. ; Ministry of Education, Science and Technological Development of Serbia for financial support, project number 173015. The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). J.C.M. Barreira thanks FCT, POPH-QREN and FSE for his grant (SFRH/BPD/72802/2010). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063) and project ref. BFU2012-35228

Organic acids are primary metabolites that play important roles in plant metabolism and confer distinct flavors in fruits. Their consumption is beneficial for humans, namely against certain illnesses. The food industry uses them as preservatives and flavor enhancers. In fruits conservation and transport, organic acids should be preserved at all costs in order to maintain physical quality and pleasant flavors until they reach the consumer. In 2010, due to European legislation, methyl bromide was banned as a conservation method for chestnuts due to its toxicity to operators and negative effects to the environment. Since then, various innovative techniques have been pursued, and irradiation has proved to be a viable, cheap and environment friendly one. Our research group has studied that both gamma and electron beam irradiation as a conservation method in Portuguese chestnuts and proven that they do not alter in a significant way the nutritional value and antioxidant potential of these fruits. Herein, the influence of increasing doses of electron beam irradiation (0- control, 0.5, 1, 3 and 6 kGy) and different storage times (0, 30 and 60 days), in the organic acids profile of Portuguese chestnuts, was studied. Ultra-fast liquid chromatography coupled to a photodiode array detector (UFLC-PDA) was used to quantify oxalic, quinic, malic, ascorbic, citric, fumaric, succinic and shikimic acids. Our results indicate that the irradiation doses did not significantly influence the quantity of organic acids in the samples, proving to be a safe and valuable conservation technique. ; ON.2/QREN/EU Project no.13198/2010, FCT, Portugal, and COMPETE/QREN/EU for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). A.L. Antonio, L. Barros and J.C.M. Barreira also thank FCT, POPH-QREN and FSE for their grants (SFRH/PROTEC/67398/2010, SFRH/BPD/4609/2008 and SFRH/BPD/72802/2010, respectively). Finally they also thank Prof. A. Chmielewski, Director of the Institute of Nuclear Chemistry and Technology, for allowing e-beam irradiations.

Since 2010, methyl bromide, a widely used fumigant was banned from the European Union under the Montreal Protocol guidelines, due to its deleterious effects on health and risk to the environment. Since then, many alternatives for chestnut conservation have been studied (hot water dip treatment being the most common), among them, electron beam irradiation has been proposed as being a safe, clean and cheap alternative. Herein, the effects of this radiation at different doses up to 6 kGy and over storage up to 60 days in the amounts and profile of nutritionally important organic acids were evaluated. Chestnuts contained important organic acids with quinic and citric acids as main compounds. Storage time, which is traditionally well accepted by consumers, caused a slight decrease on quinic (13 to 9 mg/g), ascorbic (1.2 to 0.8 mg/g), malic (5 to 4 mg/g), fumaric (0.4 to 0.3 mg/g) and total organic (33 to 26 mg/g) acids content. Otherwise, irradiation dose did not cause appreciable changes, either individually or in total (28 to 27 mg/g) organic acid contents. Electron beam irradiation might constitute a valuable alternative for chestnut conservation. ; ON.2/QREN/EU Project no.13198/2010 for financial support of this work, to Fundação para a Ciência e a Tecnologia (FCT, Portugal) and COMPETE/QREN/EU for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). A.L. Antonio, L. Barros and J.C.M. Barreira also thank to FCT, POPH-QREN and FSE for their grants (SFRH/PROTEC/67398/2010, SFRH/BPD/4609/2008 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.