水噴霧加熱法によるフライ油の変質について(第3報)
フライ油の変質の型と安定性の低下について
1967 年 16 巻 8 号 p. 449-453
詳細
1967 年 16 巻 8 号 p. 449-453
The object of this study is to elusidate the relation between fat stability and the type of fat deterioration occured during deep fat frying.
Soybean oil was deteriorated in the continuous water-spraying and heating system' by controlling the supply of air and water, and deteriorated oils of four types were prepared. Type-1 was obtained by heating without air and water (Experiment-1), Type-2 was with air but without water (Experiment -2), Type-3 was with water but without air (Experiment-3), and Type-4 was with air and water (Experiment-4). Experimental condition and properties of deteriorated oils were shown in Table-15.
The fat stability of four types of deteriorated oils above mentioned were compared by the length of induction period, and the effect of antioxidants or synergists to these oils were evaluated (Fig.-12). Induction period and effectiveness of antioxidants were measured by weighing method mentioned by Dr. H.S. Olcott et al.
It was observed that, in Type-1, no any deterioration occured, therefore, good stability was maintained, and the addition of antioxidants or synergist was very effective.
In Type-2 and 4, thermal oxidation occured, and the fat stability lowered very rapidly and its stability could not be recovered almostly by the addition of synergist, and also, the addition of antioxidants was, no longer, uneffective for the oil when the oil went over a certain deterioration limit. In Type-3, thermal oxidation did not occur, but the hydrolysis occured and the fat stability also lowered, but its stability could be effectively recovered by the addition of antioxidants or synergist. This result shows that the lowering of fat stability in Type-3 was not from the deterioration of oil itsself, but from the loss of antioxidants by steaming and from the increase in iron content came from the fabricating material.
The lowering of fat stability of soybean oils thereinto added the antioxidants or synergist before heating, and the influence of fabricating material of testing beaker to the fat stability were also examined.
