Page:Principles preservation fish by salt.djvu/20

14 open, scraped, and washed before the salt is applied. By what criteria can we judge the merits of these various methods? The best way to answer this question is: Other conditions being held constant, which method or methods of cleaning result in least decomposition during the salting process?

A series of trials was made by cleaning the fish by the various methods and salting them by the same process and determining the amounts of amino acid nitrogen developed. Two sets complete were tried, one consisting of one sample each cleaned by the various methods and held at a temperature of 79° F. during the salting process; another set similar to the preceding but held at 88° F. during the salting process. Both temperatures are high for salting fish, and the test is correspondingly severe. The results are shown in the following table, which is abbreviated from the paper by Tressler:

Since amino acid nitrogen indicates decomposition, the conclusions from this table are entirely obvious. Only those fish were successfully salted at temperatures of 79 and 88° F. which had been thoroughly cleaned and from which all blood had been removed. While these high temperatures were chosen for the test because severe tests bring out differences in a more striking way, the differences will still exist even at lower temperatures and manifest themselves in the poorer or better quality of product. Now, it may be either the blood or flesh, or both, in which the decomposition takes place. Since the perfectly clean fish decompose only slightly, it may be that only the blood decomposed in such cases as those given in the table, and that the decomposed blood pervading the otherwise sound tissue gave the appearance and odor of decomposition to the whole fish. On the other hand, it is possible that the enzymes in the blood when present operate to decompose not only the blood proteins but the tissue proteins also. However, this may be, the indisputable fact remains that if fish are to be salted in very warm weather it is absolutely