Studies on Citric Acid for Stabilization of Milk Research with Sephadex G-25 Chromatography

In order to examine the changes of citric acid and protein in coagulated milk treated by heat (125°-90min.), acid (pH 4.6) and rennin, and those in frozen milk, studies were per-formed with Sephadex G-25 chromatography. The results obtained were as follows: 1) It was deduced that elution pattern of citric acid in every treatment was almost the same as in raw skimmilk and was also eluted in nearly fixed fraction number. But chroma-togram of protein in each milk indicated the respective characteristic pattern. 2) In heated whey at 125°-90min, it was found that citric acid had 2 peaks on the chromatogram, and protein was denatured distinctly. 3) In rennin whey, elution pattern of citric acid was the same as in raw milk. 4) When the freezing period at-27-30°Cwas longer, it was deduced that citric acid in frozen milk was changed and protein was also denatured to unstable condition.