The yellow discoloration in canned oysters, which appeared after several months of storage, has been proven to be due to carotenoid pigments which were contained in the liver of the oyster. It was found after making carbon disulfide extractions of the liver and of the discolored tissue from canned oysters obtained from four different areas that the yellow pigments in the discolored tissue and in the livers of these oysters were identical. This conclusion was drawn following ten separate chromatographic analyses of these extracts. Analysis with the spectrograph further showed that the pigments responsible for the major portion of the discoloration was carotene. The absorption bands of this pigment in a carbon disulfide solution were found to lie at 521 and 485 millimicrons. These lines corresponded to those for beta carotene. It was also observed that these carotenoid pigments from the liver diffused slowly through the surrounding tissue and that the time required for the color to reach the surface of the oyster depended upon the thickness of the tissue. In a preliminary test it was also found that higher temperatures in storage tended to hasten the discoloration while samples held at zero degree Fahrenheit inhibited the diffusion of the color to the surface. / Graduation date: 1940