THE OCCURRENCE OF A RED PIGMENT PRODUCING ORGANISM IN CORN MASH OF THE ACETONE BUTYL ALCOHOL FERMENTATION

The formation of a pink or red color on the surface of corn mash from plant cookers is not uncommon. This pigment is found not only in samples of corn mash cooked under plant conditions (2400 to 2801F.) but also to a limited degree in mash prepared in the laboratory. A pale pink color is first noted on the surface of mash which has been allowed to stand for two to three days or longer and this pigment later changes to a dark red or reddish brown. Since the pigment is not commonly found in the mash heated at low temperatures, but in samples heated above 100°C., it was thought at first that air contamination, possibly mold spores, might be the cause. No evidence, however, could be found to support this supposition. As a result of many tests it was found that samples of mash exposed to air contamination rarely developed a pink or red pigment. More conclusive evidence concerning the cause of the pigment was obtained from microscopic examinations of pink corn mash. Samples which were taken directly from the cookers at the end of the cooking cycle and from various parts of the filing line were stored at 370C. Great care was taken to draw these samples under conditions which prevented outside contamination. At first it was thought that this contamination was due to molds; after