Partitioning studies of α-lactalbumin in environmental friendly poly (ethylene glycol)--citrate salt aqueous two phase systems.

Aqueous two-phase systems (ATPS) formed by polymer and salt have been utilized to enrich the desired biomolecule into one of the phase with higher yield and purity. The eco-friendly, biodegradable poly ethylene glycol (PEG) and different citrate salts were chosen as ATPS phase components to investigate the partitioning behavior of α-lactalbumin (α-La). System factors and process parameters such as type and concentration of salt, molecular weight and concentration of PEG, pH, temperature and the effect of additives were studied and the results are discussed in detail. PEG 1000-tri-potassium citrate system yields high partition coefficient of 20 with a better yield of 98 % in the top phase. The addition of NaCl as an additive and acidic pH lowers the yield of α-La in the top phase. Influence of phase volume ratio (V(r)) on partitioning was studied and found that the partition coefficient remains almost constant along the tie line. High yield was achieved at a V(r) of 3.5 at the tie line length of 50.63 (%, w/w).

Lipase mediated synthesis of rutin fatty ester: Study of its process parameters and solvent polarity.

Lipophilization of antioxidants is recognized as an effective strategy to enhance solubility and thus effectiveness in lipid based food. In this study, an effort was made to optimize rutin fatty ester synthesis in two different solvent systems to understand the influence of reaction system hydrophobicity on the optimum conditions using immobilised Candida antartica lipase. Under unoptimized conditions, 52.14% and 13.02% conversion was achieved in acetone and tert-butanol solvent systems, respectively. Among all the process parameters, water activity of the system was found to show highest influence on the conversion in each reaction system. In the presence of molecular sieves, the ester production increased to 62.9% in tert-butanol system, unlike acetone system. Under optimal conditions, conversion increased to 60.74% and 65.73% in acetone and tert-butanol system, respectively. This study shows, maintaining optimal water activity is crucial in reaction systems having polar solvents compared to more non-polar solvents.

Modelling, analysis and optimization of adsorption parameters for H3PO4 activated rubber wood sawdust using response surface methodology (RSM).

Adsorption capacity of Cu(2+) from aqueous solution onto H(3)PO(4) activated carbon using rubber wood sawdust (RSAC) was investigated in a batch system. Kinetic and isotherm studies were carried out, the thermodynamic parameters like standard Gibb's free energy (Delta G degrees), enthalpy (Delta H degrees) and entropy (DeltaS degrees) were evaluated. The pseudo-second-order model was found to explain the kinetics of Cu(2+) adsorption most effectively. The process optimization was performed through Central Composite Rotary Design using response surface methodology (RSM) by Design Expert Version 5.0.7 (STAT-EASE Inc., Minneapolis, USA). An initial concentration of 35 mg L(-1), temperature of 26 degrees C, carbon loading of 0.45 g(100mL)(-1), adsorption time 208 min and pH of 6.5 was found to be the optimum conditions for the maximum uptake of copper ions of 5.6 mg g(-1) in batch mode.