鰭長および黄肌鮪青肉に関する研究

Abstract

As a part of studies for predicting the green meat appearance in canned albacore and yellow-fin tuna, various kinds of methods chiefly comprising known ones were examined of their reliability. After a number of examinations it was discovered that a certain compound, which is occasionally contained in flesh of albacore and yellow-fin tuna and gives a yellow ninhydrin paperchromatographic spot from alcoholic extracts, is closely connected with the occurrence of green meat. This compound, though it is still opened to be identified, has been presumed as a sort of peptide from some results of examination. The judgement from color of kidney, on the other hand, proved to be little reliable except when the flesh examined was that of yellow-fin tuna, especially of large body-lengths. The chromatographic judgement, in turn, despite of its far greater reliability as compared with the criticism referred to the kidney color seems also not perfectly satisfying as it requires time in its practice. Since the greening tendency latent all over the muscular system of fish body was confirmed to be predicted from the behavior of small pieces of flesh on cooking, judgement by cooking test of small flesh pieces may be said for the time being to be a most practicable method of predicting the tendency. It must be noticed, however, the appearance of greenish color in the sample pieces depends upon the time of cooking. Too short a time of cooking proved always to fail in causing the color to develop irrespective as to whether the pieces were boiled in aqueous common salt or in plain water or canned and subjected to the routine heating in retort.