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). The authors are also grateful to Clarinda Paixão, from Américo Duarte Paixão Lda, for samples providing.
The extracts from the leaves of Ginkgo biloba are widely used in medicines and food supplements in order to overcome different health problems. To provide decontamination, irradiation is a safe and effective technique, particularly suitable to be integrated in quality control of the postharvest samples. In this study, different analytical methods were applied to assess the effects of gamma irradiation (1 and 10 kGy) in G. biloba color, chemical composition and antioxidant properties. Irradiation preserved macronutrients, fatty acids, γ- and δ-tocopherols, fructose, trehalose, quinic and shikimic acids. In particular, 1 kGy protected α-tocopherol, oxalic and malic acids contents, while 10 kGy decreased α-tocopherol, glucose, sucrose, oxalic and malic acids level. Nevertheless, this dose was the most effective for antioxidant activity. Overall, 1 kGy would be the recommended dose to maintain nutritional profile of G. biloba, protect specific molecules and also increase antioxidant activity of infusion and methanolic extracts prepared from its leaves.
