Enzymatic hydrolysis of chicken viscera proteins in the presence of an ionic liquid as a strategy to improve the antioxidant properties of the hydrolysates

Aiming to explore the use of ionic liquids (ILs) not yet described in the literature, this work evaluated the hydrolysis of proteins from chicken viscera using the protease Alcalase modified and unmodified by the IL tetramethylammonium bromide. The protein hydrolysates produced in the presence of the IL presented values of antioxidant activities 40% higher than the hydrolysates obtained without IL. In addition, with the presence of the IL, it was possible to obtain protein hydrolysates from chicken viscera with similar antioxidant activities, compared to the protein hydrolysates produced without IL, using 1/3 of the amount of enzyme.

Effect of Quaternary Ammonium Salt Addition to Conventional Biodiesel Production Process

Biodiesel on a commercial scale is largely produced by transesterification using a conventional homogeneous catalyst like KOH and NaOH. The major problem associated with conventional homogeneous transesterification process is that it is prone to water & FFA content. This problem can be mitigated with some process modification using quaternary ammonium salts. In the present study, the reaction between waste palm oil & methanol was carried in a batch reactor at 65oC & various molar ratios of oil to methanol. Further, the effect of various dosages of tetramethylammonium bromide (TMAB) addition to this reaction was studied. Results show that there is a strong influence of TMAB (a phase transfer catalyst) on the methanol requirement during the reaction and also on the washability characteristics of the produced biodiesel. It was observed that there is a considerable decrease in the molar ratio of methanol to oil requirement during the reaction. Moreover, the addition of TMAB has enhanced the washability of the final biodiesel product by forming less foam. This has a direct advantage of decreasing the water requirement during the purification process.

Comparison of Hupresin® to Procainamide-Sepharose for Purification of Butyrylcholinesterase and Acetylcholinesterase

Affinity chromatography on procainamide-Sepharose has been an important step in the purification of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) since its introduction in 1978. The procainamide affinity gel has limitations. In the present report a new affinity gel called Hupresin® was evaluated for its ability to purify truncated, partly-deglycosylated human butyrylcholinesterase (rHuBChE) expressed in a stably transfected CHO cell line. We present a detailed example of the purification of rHuBChE secreted into 3940 mL of serum-free culture medium. The starting material contained 13,163 units of BChE activity (20.9 mg). rHuBChE was purified to homogeneity in a single step by passage over 82 mL of Hupresin® and elution with 0.1 M tetramethylammonium bromide in 20 mM TrisCl pH 7.5. The fraction with the highest specific activity of 630 units/mg contained 11 mg of BChE. Hupresin® is superior to procainamide-Sepharose for purification of BChE, but is not suitable for purifying native AChE because Hupresin® binds AChE so tightly that AChE is desorbed with denaturing solvents such as 50% acetonitrile or 1% trifluoroacetic acid. Procainamide-Sepharose will continue to be useful for purification of AChE.