Saponins-Clay Modified Materials A New Approach Against Callosobruchus Subinnotatus In Stored Products

The adsorbent power of montmorillonite clay treated with saponins extracted from kernels of Balanites aegyptiaca was evaluated using the terpenes compounds content in the essential oil of Ocimun gratissimun. The properties of formulations based on O. gratissimum essential oil and montmorillonite clay were modified after treatment of clay with saponins. Sabinene linalool terpinen-4-ol amp945-gurjunene neo-allo-ocimene amp946-caryophyllene sabinol and amp946-pinene terpenic compounds contained in essential oil were chosen to follow their adsorption. The kinetics adsorption of essential oil from a solution onto the adsorbents treated clay and untreated clay was explored experimentally. Non-linear form of pseudo-second-order model showed a better fit with good correlation coefficient. Intraparticle diffusion model were also used. Non-linear form of Langmuir isotherm model was applied and the data correlated well and the maximum adsorption capacity was found to be 1.07 mol.g-1 with regards to sabinol. Adsorption capacity of montmorillonite clay treated with saponins is greater than that of the untreated clay. The most adsorbed compounds are the oxygenated terpenic compounds. Treatment of clay with saponins increases the persistence of the insecticidal activity of essential oil adsorbed on montmorillonite clay. The mortality of Callosobruchus subinnotatus decreased from 96 to 70 and from 96 to 13.12 for O. gratissimun essential oil adsorbed on saponins-clay and O. gratissimun adsorbed on untreated clay after 42 days respectively. These results can be used in the production of bioinsecticides