Gamma irradiation as an alternative to preserve the chemical and bioactive characteristics of plants widely consumed as infusions

Introduction Some of the plants included in our diet require effective conservation technologies to ensure their use in the best conditions. Irradiation may allow the decontamination of plants, maintaining their chemical, organoleptic, nutritional and bioactive properties [1,2]. Objectives In this study, the effects of gamma irradiation (1 and 10 kGy) in chemical, nutritional and antioxidant properties of Aloysia citrodora, Melissa officinalis, Melittis melissophyllum and Mentha piperita, were evaluated. Material and Methods The nutritional value was determined by official methodologies for food analyses; free sugars were analysed by HPLC-RI, fatty acids by GC-FID, organic acids by UFLC-PDA and tocopherols by HPLC-fluorescence. Antioxidant properties of methanolic extracts and infusions were evaluated by the free radical scavenging activity, reducing power and inhibition of lipid peroxidation. Results Despite some variations observed in the nutritional value, it was not possible to identify evident tendencies with the exception of proteins, which increased in all the samples irradiated with 10 kGy. However, in general, when analysed in an integrated approach non-irradiated sample (control) and irradiated ones were grouped indiscriminately indicating that the irradiation treatment caused no sufficient changes for defining a specific chemical profile. Conclusions Thus, it can be concluded that gamma irradiation (up to 10 kGy) is a viable technology for studied Lamiaceae and Verbanaceae species. This is advantageous since the dose of 10 kGy guarantees disinfection and decontamination of specimens