Authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to research centres CIMO (PEst-OE/AGR/UI0690/2011), REQUIMTE (PEst-C/EQB/LA0006/2011) and ALIMNOVA research group from UCM. Â. Fernandes and J.C.M. Barreira thank FCT, POPH-QREN and FSE for their grants (SFRH/BD/76019/2011 and SFRH/BPD/72802/2010, respectively). Dr. A. Rafalski, for e-beam irradiations and Prof. A. Chmielewski, General Director of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, for allowing e-beam irradiations.
In the present study, electron-beam irradiation was applied to dried samples of Boletus edulis and Macrolepiota procera to evaluate the effects on their fiber composition. Both species presented an important percentage of dietary fiber, soluble and insoluble in different ratios. These high fiber levels are an interesting feature, allowing considering mushrooms as an alternative source of dietary fibers in the highly competitive market of fiber-enriched food products. In B. edulis samples, insoluble fiber and total fiber amounts were significantly lower in samples irradiated with 10 kGy, but soluble fiber had no significant changes for any of the assayed doses, while total available carbohydrates were significantly lower in unirradiated samples. M. procera samples irradiated with 6 kGy presented less total fiber, insoluble fiber and carbohydrates, but the same dose allowed the highest contents in soluble dietary fiber. In general, the irradiated samples, especially for higher doses, gave some significant changes in the total available carbohydrates and dietary fibers content. Nevertheless, the resulting differences still allow considering these species as good natural fiber sources, maintaining their potential health effects, while promoting a clean way to disinfest and decontaminate these highly perishable products.
