Low dose gamma-irradiation as a suitable solution for chestnut (Castanea sativa Miller) conservation: effects on sugars, fatty acids and tocopherols

• Autor(a) principal: Fernandes, Ângela
• Data de Publicação: 2011
• Outros Autores: Antonio, Amilcar L., Barros, Lillian, Barreira, João C.M., Bento, Albino, Botelho, M. Luísa, Ferreira, Isabel C.F.R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/6228
• topic: Irradiated chestnuts; Gamma irradiation; Sugars; Fatty acids; Tocopherols

Along with dehydration, the development of insects and microorganisms is the major drawback in chestnut conservation. Irradiation has been regaining interest as an alternative technology to increase food products shelf-life. In the present work, the effects of low dose gamma irradiation on sugars, fatty acids and tocopherols composition of chestnuts stored at 4 ºC for different storage periods (0, 30 and 60 days) was evaluated. The irradiations were performed in a 60Co experimental equipment, for 1 h (0.27 +/- 0.04 kGy) and 2 h (0.54 +/- 0.04 kGy). Changes in sugars and tocopherols were determined by high performance liquid chromatography (HPLC) coupled to refraction index (RI) and fluorescence detections, respectively, while changes in fatty acids were analysed by gas-chromatography coupled to flame ionization detection (GC-FID). Regarding sugars composition, storage time proved to have higher effect than irradiation treatment. Fructose and glucose increased after storage, with the corresponding decrease of sucrose. Otherwise, tocopherols content was lower in non-irradiated samples, without a significant influence of storage. Saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids levels were not affected neither by storage nor irradiation. Nevertheless, some individual fatty acids concentrations were influenced by one of both factors, such as the increase of palmitic acid in irradiated samples or the decrease of oleic acid after 60 days of storage. Overall, the assayed irradiation doses seem to be a promising alternative treatment to increase chestnuts shelf-life, without affect the profile and composition in important nutrients.