魚油の油焼に関する研究-XIII

抄録

In concluding the present series of works under the same title, the author intends to verify the presence of half aldehyde in autoxidized oil, for he has already arrived at the conviction that, if half aldehyde is permitted to be born when oil is autoxidized, the coloring of so-called oxidized acid is naturall traced back at least partially to the coloring of such aldehyde.
Now, the presence of half aldehyde in autoxidized oil has proved definite from the experimental data shown in Table 1. These results lead to the conclusion that at least part of the characteristic color of oxidized acid, accordingly also the main coloring matter of discolored oil, springs from half aldehyde formed in the oil.
Diketostearic acid and neutral aldehydes, whose existence are now also conclusive from the table, brown likewise when treated by base, but the color thus developed readily fades away on subsequent acidfication. Therefore, these carbonyl compounds are not to be responsible for the permanent color of oxidized acid, even if they may participate in the basic discoloration such as often observed on fish oil.