Case Study of Bacterial Decontamination of an Aromatic and Medicinal Plant: Decontamination of Thymus Satureioides by Gamma Radiation at Low Doses and Impact on Hygienic and Physicochemical Quality

The purpose of our study is to verify the usefulness of gamma irradiation treatment at low doses (0.25, 0.5 and 1 kGy) combined to vacuum packaging on commercial teas of Thymus satureioides deliberately contaminated with Escherichia coli. The efficiency and the influence of the process on contamination level and the shelf life of the product were studied. The phenolic composition and concentration were identified in the unirradiated and irradiated thyme. The total phenolic content (TPC) was assayed by the Folin-Ciocalteu method, the individual phenolic compounds were determined by high liquid chromatography (HPLC) and the essential oil was characterized by gas chromatography coupled to mass spectroscopy (GC-MS). The plant was observed by scanning electrons microscopy and the radioactivity effect was analyzed. The results show a complete decontamination of thyme depending to the dose and the storage time. Privileged hygienic quality was found in the irradiated thyme with the highest concentrations of polyphenols. The process showed the conservation of thyme quality without any alteration of its characteristics or radioactivity effect

Valorisation of cellulosic waste basic cactus to prepare activated carbon

The cellulosic waste is the most abundant material in the earth. It is considered as a renewable polymer of wood cell walls and plant cells. It is used in different fields mainly as sustainable potential precursors and it is useful for the preparing activated carbon.The purpose of this study is the valorisation and production of activated carbon from cellulose waste, old cladodes of Ficus indica cactus optunia, and the residue of prickly pear seeds after oil extraction. Preparation and characterization of activated carbon (AC) from the two wastes by chemical treatment, phosphoric acid H3PO4 at a temperature of 450 °C has shown a very good adsorption of methylene blue and iodine. This treatment illustrated an important surface area of 820 m2/g for waste seeds and more than 470 m2/g for waste cactus cladodes. Analysis by infrared and pH point of zero charge showed a basic character for both carbons active developed. Keywords: Cactus, Activated carbon, Fig tree barbarism, Chemical activatio