A method, based upon the color reaction between NH3, thymol, and bromine, uses ammonia as an index of decomposition in fresh or frozen crabmeat. The color is extracted into re-butyl alcohol and net absorbance is determined by subtracting absorbance at 475 mμ. from that at 682 mμ. Sensitivity is about 1 ppm NH3. The method is very rapid and requires no special apparatus. Samples of crabmeat decomposed under controlled conditions were examined and graded organoleptically. Ammonia content was determined and found to increase uniformly and rapidly with spoilage. Good reproducibility and low results were obtained on fresh crabmeat. Ammonia can be detected by the method before spoilage can be detected organoleptically.

A key based on characteristic scale patterns has been developed to distinguish the five species of canned salmon. The scales are simply removed from the fish skin, examined under magnification, and keyed as to species. Nine of ten cans of unknown salmon were correctly identified by laboratory personnel unfamiliar with salmon species. The one error was due to inadequate explanation of terms used in the key. It is recommended that the amended key be subjected to collaborative study.