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- Conservation of wild mushrooms through electron beam irradiationPublication . Fernandes, Ângela; Antonio, Amilcar L.; Rafalski, Andrzej; Barreira, João C.M.; Oliveira, Beatriz; Martins, Anabela; Ferreira, Isabel C.F.R.The high perishability is a characteristic of the mushrooms consumed in fresh. Therefore, it is mandatory the application of effective conservation technologies to preserve and protect their chemical composition and nutritional value. Drying processes are widely used, but do not avoid the development of bacteria and fungi which have the ability to survive for long periods of time in dry foods, causing the loss of some nutrients and leading to food browning and oxidation of lipids and vitamins [1]. Irradiation appears as an alternative to food preservation assuring and maintaining its quality [2]. In this work, the effects of electron beam irradiation and storage time on nutritional and chemical parameters of wild samples of Macrolepiota procera (Scop.) Singer, previously submitted to a drying process (oven at 30 ºC), were assessed. The wild mushroom samples were collected in Trás-os-Montes; electron beam irradiation (doses 0.5, 1 and 6 kGy) was carried out in the INCT- Institute of Nuclear Chemistry and Technology in Warsaw, Poland and the analyses were performed over the storage period (0, 6 and 12 months). The results were compared with a control (non-irradiated samples). The nutritional value was determined according to the official procedures of food analysis, while the profiles of fatty acids, tocopherols, mono and oligosaccharides were obtained by chromatographic techniques [1]. The irradiation showed a better capacity to maintain the nutritional and chemical profile, in comparison with the storage time. Effectively, the storage time had a significant effect in all parameters, but fatty acids undergone significant changes both with irradiation doses and storage time. Electron beam irradiation can be considered a suitable technique for conservation of mushrooms for long periods of time, attenuating the changes caused by the drying treatment.
- Effect of γ-radiation in the survival of Aspergillus parasiticus in chestnutsPublication . Calado, Thalita; Antonio, Amilcar L.; Rodrigues, Paula; Venâncio, ArmandoIn this study, the use of rays as an inactivation agent agains one of the most ubiquous and mycotoxigenic fungus - Aspergillus parasiticus - was studied. Chestnuts were previous incoulated with a spore suspension of one strain of A. parasiticus. After irradiation the growth of colonies were observed during 4 days. In general, the higher level of radiation the lower survival rate.
- Methods combined with irradiation for food preservationPublication . Pinela, José; Antonio, Amilcar L.; Ferreira, Isabel C.F.R.In recent years, consumers have been looking for safer, higher quality foods, but also more convenient and ready-to-eat. Quality assurance through the elimination of pathogenic microorganisms has been a major concern for the food industry. However, an alarming number of diseases are still caused by different foodborne pathogens, which cause hundreds of deaths.1 Escherichia coli and Listeria monocytogenes are food poisoning microorganisms frequently involved in microbial outbreaks. To ensure the safety and stability of food during storage, different physical, chemical, and biological preservation methods have been developed and are used in the food industry.2–4 Among non-thermal physical technologies of food preservation, irradiation has become a standard disinfestation and decontamination method worldwide. 5 This process consists in subjecting packaged or in-bulk foods to a controlled dose of ionizing energy, utilizing g-rays emitted by 60Co (or less frequently by 137Cs) radioisotopes, or high-energy electrons (e-beam) and X-rays produced by machine sources.5,6 It is effective for improving food safety and provides a safe quarantine solution.7 Irradiation is also used to prevent sprouting and post-packaging contamination, delay postharvest ripening and senescence processes, and is thereby used for shelf-life extension.8 However, the dose required to ensure safety through the elimination of pathogenic and spoilage microorganisms can sometimes adversely affect the food quality. To avoid losses and increase the effectiveness of the treatment, irradiation has been applied in combination with other preservation methods. These combinations allow reducing the dose required to eliminate or reduce microbial populations due to the occurrence of synergistic or additive effects among the applied preservation factors.9–12 Thus, the microbial radiosensitization can be enhanced and food quality attributes preserved more effectively.13–15 Several preservation treatments involving the use of g-ray, X-ray, or e-beam irradiation in combination with microbicidal, microbiostatic, preventive/ protective, or multifunctional hurdles will be detailed in this chapter. Aspects to consider in the design of these treatments, as well as the strengths and weaknesses of these combinations will be emphasized, namely the impact on pathogenic microorganisms and quality parameters.
- Chemical composition of Boletus pinophilus and Clitocybe subconnexa: preservation with gamma irradiationPublication . Fernandes, Ângela; Antonio, Amilcar L.; Barreira, João C.M.; Martins, Anabela; Oliveira, Beatriz; Ferreira, Isabel C.F.R.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.
- Espectroscopia Raman na caracterização de alimentos: a castanha como exemploPublication . Antonio, Amilcar L.; Cerqueira, M. FátimaA castanha é um fruto sazonal mediterrânico, com uma importância económica significativa em algumas regiões, estando Portugal entre os 5 maiores produtores deste fruto na Europa, com um total superior a 20 000 ton. e um valor directo para os produtores de mais de 20 milhões de Euros. A comercialização e valorização deste fruto assentam sobretudo no seu calibre. Na indústria, a produção de subprodutos a partir da castanha, com maior valor acrescentado, como o “marron glacé” (castanha caramelizada), tem em conta não só o seu calibre como as diferentes variedades de castanhas. Diferentes variedades apresentam diferentes características físicas e químicas que facilitam o seu processamento industrial ou o inviabilizam, se esta não for a adequada. A possibilidade de utilizar ferramentas que permitam a sua fácil e rápida discriminação pode ser uma mais-valia para todo o sector, do produtor à indústria. Neste trabalho preliminar procurou-se ver até que ponto a Espectroscopia Raman permite (ou não) a discriminação de duas variedades de castanha da região de Trás-os-Montes, Portugal. Os resultados preliminares evidenciam modos vibracionais dos constituintes da castanha, nomeadamente amido. Relativamente à possibilidade de diferenciação de variedades de castanhas estes resultados preliminares parecem indicar a necessidade de análises complementares, que serão objecto de trabalho futuro.
- Effects of gamma irradiation on sugars, fatty acids and tocopherols of chestnuts (Castanea sativa Miller)Publication . Barros, Lillian; Antonio, Amilcar L.; Barreira, João C.M.; Fernandes, Ângela; Bento, Albino; Botelho, M. Luísa; Ferreira, Isabel C.F.R.As seasonal products chestnuts have to be postharvest treated to increase their shelf-life. The most common preservation method for chestnuts is the use of chemical fumigation with methyl bromide, a toxic agent that is under strictly use under Montreal Protocol due to its adverse effects on human health and environment. Food irradiation is a possible feasible alternative to substitute the traditional quarantine chemical fumigation treatment. The main studies in chestnuts irradiation were done in an Asian variety, which is bigger and sweeter than the European types. However, on Portuguese varieties nothing has been reported. Herein, the influence of irradiation and storage time in sugars, fatty acids and tocopherols profiles/quantities in chestnuts obtained in Trás-os-Montes, Northeast Portugal, was evaluated for the fist time.
- IntroductionPublication . Antonio, Amilcar L.; Cabo Verde, Sandra; Ferreira, Isabel C.F.R.Food irradiation is not new but is a prevalent current topic and challenging research field with new outcomes. Nowadays, food irradiation can be regarded as quality food processing technology with the capacity to answer the growing problem of food poisoning, with the added benefit of reducing spoilage and extending the food shelf life. Innovative improvements in food irradiation technologies can be expected following recent research achievements. This introductory chapter overviews several food irradiation perspectives (past, present, and future) that will be further discussed in detail in the other chapters of the book.
- Irradiação gama como uma alternativa segura para preservar as características químicas e bioativas de plantas utilizadas para fins medicinaisPublication . Pereira, Eliana; Antonio, Amilcar L.; Barreira, João C.M.; Barros, Lillian; Bento, Albino; Ferreira, Isabel C.F.R.As plantas usadas pela indústria requerem tecnologias de conservação e descontaminação eficazes a fim de garantir a sua utilização nas melhores condições. A irradiação é uma tecnologia capaz de descontaminar as plantas, mantendo as propriedades químicas, organoléticas, nutricionais e bioativas. Neste estudo avaliaram -se os efeitos da irradiação gama relativamente nas propriedades químicas, nutricionais e antioxidantes de várias plantas aromáticas e medicinais. Em geral, uma comparação entre as amostras não -irradiadas (controlo) e irradiadas mostrou que o tratamento por irradiação não causou alterações suficientes para definir um perfil químico específico. Assim, a irradiação gama (até 10 kGy) é uma tecnologia viável para as espécies estudadas.
- Nutritional value, bioactive compounds and antioxidant properties of three edible mushrooms from PolandPublication . Heleno, Sandrina A.; Ferreira, Raíssa Carolina; Antonio, Amilcar L.; Queiroz, Maria João R.P.; Barros, Lillian; Ferreira, Isabel C.F.R.Mushrooms contain a multitude of biomolecules with nutritional and/or biological activity. Among the bioactive molecules, phenolic compounds and tocopherols are the most responsible for their antioxidant activity. In the present work, Boletus edulis, Lentinus edodes and Xerocomus badius, three edible mushroom species originated from Poland, were analyzed for their chemical composition and antioxidant activity. Carbohydrates were the most abundant macronutrients, followed by proteins and ash. Fructose, mannitol and trehalose were the prevalent sugars, but glucose was only found in B. edulis. Polyunsaturated fatty acids predominated over mono and saturated fatty acids. Palmitic, oleic and linoleic acids were abundant in the three samples. α- and β- Tocopherols were quantified in all the samples, but γ-tocopherol was only identified in X. badius. Oxalic and fumaric acids were quantified in the three samples; quinic acid was only present in L. edodes, and malic and citric acids were only found in X. badius. p-Hydroxybenzoic, protocatechuic and cinnamic acids were quantified in all the species, while p-coumaric acid was only found in B. edulis. This species and X. badius revealed the highest antioxidant properties, being B. edulis more effective in radicals scavenging activity and reducing power, and X. badius in lipid peroxidation inhibition, which is related with the highest amounts in phenolic compounds and tocopherols, respectively.
- Desinfestação da castanha por irradiaçãoPublication . Antonio, Amilcar L.A irradiação de alimentos é um processo industrial utilizado para diversos fins: esterilização, desinfestação ou para aumentar o tempo de prateleira de produtos alimentares. No entanto cada alimento deve passar por um processo de validação, de forma a garantir que as suas características organoléticas e nutricionais não são alteradas. Este projeto de inovação teve como objetivo validar a técnica de irradiação (gama e feixe de electrões) para conservação de castanha, dando resposta a uma necessidade da agro-indústria que processa e comercializa este fruto. Os valores de fruto exportado representam aproximadamente 13 milhões de euros, um valor significativo se considerarmos que cerca de 85% da produção tem origem na região de Trás-os-Montes. Esta iniciativa de I&DT desenvolveu-se no âmbito de um consórcio entre entidades científicas, Instituto Politécnico de Bragança e Universidade do Minho, e uma unidade agro-industrial, Agroaguiar Lda, com a participação tecnológica do Instituto Tecnológico e Nuclear, com o apoio do programa QREN/ON.2/UE, e do Instituto Tecnológico de Química Nuclear, na Polónia, no âmbito de uma parceria internacional EUREKA (com o lema “doing business with technology”).