抄録
Oxygen content in fats and oils was investigated by a modification of the Schutze-Unterzaucher method.
Oxygen in soybean oil and colza oil heated at 180°C in air was determined periodically. The oxygen contents of soybean oil and colza oil were 9.9% and 9.2% initially and 8.2% and 9.1% after 30 hours, respectively, therefore the change in the oxygen contents was very little in this case.
Oxygen was passed through linseed oil heated at 100°C and 200°C, and the oxygen content in linseed oil determined perisdically. The oxygen content in linseed oil was initially 11.0%, that in gelatinized linseed oil heated at 100°C for 10 hours was 17.8%, and that in gelatinized one heated at 200°C for 5 hours was 15.0%. Then, oxygen content in perilla oil was similarly determined.
The oxygen content in linseed oil was determined in the process of drying test by using cobalt naphthenate as a drier. The oxygen content in linseed oil was 8.5% initially and 21.6% after 6 hours. To linseed oii, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) or isopentyl gallate was added, each mixture heated at 100°C or 200°C under the passage of oxygen, and the oxygen content was determined.
This determination of oxygen content in fats and oils affected by their aging seems to be effective for clarifying the process of their oxidation and degradation, in addition to other usual instrumental analyses.
