Sporopollenin exines: A novel natural taste masking material

Sporopollenin exines extracted from the spores of the plant Lycopodium clavatum were used to encapsulate water, sunflower oil (0.5 g/g) and differing amounts of cod liver oil (cod liver oil per gram of sporopollenin exines: 0.5 g/g, 1.0 g/g, 2.0 g/g, 4.0 g/g). A double-blind taste trial, involving 20 volunteers, was conducted to compare the products. The encapsulated oils were in the form of a fine powder up to an oil loading of 1/1 (w/w). Blind tasting could not distinguish the cod liver oil preparation up to 1/1 (w/w) loading compared to the sporopollenin exines filled with either water or sunflower oil. At a loading of 2/1 and 4/1, the cod liver oil was uniformly identified. Therefore, sporopollenin exines can be loaded highly, at up to 1 g oil to 1 g of the exines, and still remain as a dry powder and retain flavor masking, thus disguising the contents.     

Adsorption characteristics of heavy metal ions onto a low cost biopolymeric sorbent from aqueous solutions

In this study, the adsorption conditions of Cu(II), Pb(II) and Cd(II) metal ions onto sporopollenin have been studied. The different variables effecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration and temperature have been investigated. Adsorption isotherms correlated well with the Freundlich type adsorption isotherm and adsorption capacities were found to be 0.0195, 0.0411 and 0.0146 mmol g(-1) for Cu(II), Pb(II) and Cd(II) metal ions, respectively. Experimental data were also evaluated to find out kinetic characteristics of the adsorption process. Adsorption processes for three target heavy metal ions were found to follow pseudo-second order type adsorption kinetics. Intraparticle diffusion was found to take part in adsorption processes but it could not be accepted as the primary rate-determining step. The mean free energies of adsorption (E) were found to be between 8 and 16 kJ mol(-1) for the metal ions studied and therefore adsorption mechanism for the adsorbent was explained as an ion-exchange process. But it was observed that chelating effect is also playing an important role in the adsorption of metal ions onto sporopollenin. Thermodynamic parameters, DeltaH degrees , DeltaS degrees and DeltaG degrees were also calculated from graphical interpretation of the experimental data. Standard heats of adsorption (DeltaH degrees ) were found to be endothermic and DeltaS degrees values were calculated to be positive for the adsorption of Cu(II), Pb(II) and Cd(II) ions onto the adsorbent. Negative DeltaG degrees values indicated that adsorption process for these three metal ions onto sporopollenin is spontaneous.     

Isotherms and thermodynamics for the sorption of heavy metal ions onto functionalized sporopollenin

In this study, sporopollenin of Lycopodium clavatum spores was used for the sorption experiment. Glutaraldehyde (GA) immobilized sporopollenin (Sp), is employed as a sorbent in sorption of selected heavy metal ions. The sorbent prepared by sequential treatment of sporopollenin by silanazing compound and glutaraldehyde is suggested for sorption of Cu(II), Zn(II) and Co(II) from aqueous solutions. Experimental conditions for effective sorption of heavy metal ions were optimized with respect to different experimental parameters using batch method in detail. Optimum pH range of Cu(II) has occurred at pH ≥ 5.5 and Zn(II), Co(II) at pH ≥ 5.0, for the batch method. All of the metal ions can be desorbed with 10 cm³ of 0.5 mol dm⁻³ of ethylenediaminetetraacetic acid (EDTA) solution. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm equations were applied to the experimental data. Thermodynamic parameters such as free energy (ΔG^o), entropy (ΔS^o) and enthalpy (ΔH^o) were also calculated from the sorption results used to explain the mechanism of the sorption. The results indicated that this sorbent is successfully employed in the separation of trace Cu(II), Zn(II) and Co(II) from the aqueous solutions.