DETERMINATION OF PROLINE BY PAPER CHROMATOGRAPHY

In proteinous materials like meat and skin, their physicochemical properties such as tenderness, elasticity or water holding capacity seem to be related with proline and hydroxy-proline which are contained in protein structure, because these amino acids may play some role on the steric configuration of the peptide chains. Information on this point may be helpfull in evaluating materials for various types of fish products. Paper chromatographic determination of proline was reported by HRABETOVA and TUPY, who succeeded in eluting the proline-isatin coloured products with water saturated phenol. The authors modified their chromatographic method in order to reduce the developing time and to simplify the elution procedure of the proline-isatin spots. The method modified by the authors was as follows. For paper chromatographic separa-tion of proline, sample solutions and standard proline solutions of known concentration were developed with the suitable solvent system of o-cresol, acetic acid and water (100:5:10) for 15 hours at 30°C (ascending, one dimensional). Proline was detected with isatin (Rƒ value=0.72, blue spot), then the spots were eluted with water saturated phenol. Optical densities of the eluates were measured at the wave length of 610 mμ where absorption of isatin was small enough to eliminate such a process of removing the excess of isatin from the paper as needed in HRABETOVÁ'S method. The standard curve of proline-density made it possible to estimate proline content in the sample solution (range: 5-30γ of proline).