Separation of gamma-globulins from porcine plasma by reversed micellar extraction

Factors affecting the separation of gamma-globulins from porcine plasma using reversed micelles were screened based on a fractional factorial design. The optimal processing conditions for obtaining the maximum yield of gamma-globulins under various constraints of product purity were determined using response surface methodology (RSM) and nonlinear programming. Results showed that the pH and sodium chloride concentration of the aqueous phase, and the concentration of surfactant (bis-(2-ethylhexyl) sulfosuccinate sodium salt, AOT) of the organic phase were the most important factors affecting the extraction performance. An eighty-five percent product purity and ninety-seven percent yield were obtained under the extraction conditions of 400 mM NaCl, 350 mM AOT, and pH 7.0. The extract exhibited immunological reactivity against anti-pig IgG.

Formulations of controlled atmosphere agents for packaged foods

Four food grade additives-sodium ascorbate, sodium bicarbonate, sodium carbonate-10-hydrate, and ferrous sulfate-7-hydrate-were selected as the basic ingredients to formulate the controlled atmosphere agents which could effectively remove oxygen and release carbon dioxide. The mathematical models giving the relationships between the formulations and the responses (oxygen and carbon dioxide contents) were developed using response surface methodology (RSM). Within 8-24 h, the oxygen and carbon dioxide contents of all tested formulations could reach constant levels, in the ranges of 2-9% and 0-41%, respectively. These formulations were considered to be effective, safe, and easy to prepare and could be applied to wide varieties of food products.

A modified procedure for caseinophosphopeptide analysis

A modified procedure is established for analyzing caseinophosphopeptides. The sodium caseinate hydrolysate is first treated by immobilized metal ion affinity chromatography to enrich the phosphopeptides. Because of the formation of Fe(3+)-peptide complexes, ethylenediaminetetraacetic acid is added to the bound fraction eluted with the immobilized metal ion affinity chromatography to disintegrate the complexes. Thus, the subsequent high-performance liquid chromatographic analysis is facilitated. A stepwise gradient elution is also suggested to enhance the resolution of caseinophosphopeptides during high-performance liquid chromatographic analysis.