Efficacy of e-beam irradiation on shelf-life and accompanied changes in major metabolites of Desmodium gangeticum (L.) DC., an Ayurveda medicinal plant

Abstract

The effects of electron beam irradiation (5, 10 and 15 kGy) on shelf-life and major plant metabolites of an Ayurvedic medicinal plant Desmodium gangeticum was evaluated. Its root possesses incredible medicinal effects; hence powdered root sample (choorna) was subjected to radiation processing and thereby shelf-life extension. The root sample was found to possess an appreciable amount of phenolic and flavonoid compounds. TPC of untreated sample was completely deteriorated during storage. Flavonoids of untreated sample were depleted almost completely after a shelf-life of 12 months. TFC of all the irradiated samples also decreased significantly (p<0.05) under storage. Irradiated and control samples were found to possess adequate amount amounts of minerals. Electron beam irradiation with dose of 5 kGy and 15 kGy significantly decreased nitrogen and magnesium levels. In contrast, Calcium content was increased significantly (p < 0.05) on radiation processing wit 5 kGy and 15 kGy. Microbial status revealed that the untreated sample was acceptable only up to 4 months. A dose-dependent reduction in the microbial count resulted in all the radiation processed samples. Treatment with doses of 10 kGy and 15 kGy reduced the colony count to nil immediately after irradiation. Irradiation with 15 kGy kept the sample completely sterilized up to 2 months of storage and was acceptable even 12th month of storage. GC-MS analyses identified compounds with pharmacological importance such as methyl palmitate, mome-inositol, Neophytadiene, etc. Although, a slight change in mineral composition and phytochemicals were observed it could effectively decontaminate the medicinal herb and increase the shelf-life with minimum loss of major metabolites compared to other conventional methods of processing.