South african fish products. XXXI.—The composition of pilchard oil and of maasbanker oil

Abstract

A quantitative study of the saponifiable and unsaponifiable fractions of three samples of South African Pilchard oil and of one sample of maasbanker oil has been made.Differences in the iodine value of the three pilchard oils studied resxulted chiefly from differences in the mean unsaturation of the various homologous groups of fatty acids, the relative proportions of the different groups differing c comparatively little in oils of high and low iodine value. In the oil from the very lean fish the percentage of c₂₂ Acids was increased at the expense of the plamitc and c₁₈ unsturated acids, an observation which supports Lovern's view that in fasting fish the acids of lower molecular weight are preferentially utilized leading to an accumulation of acids of high molecular weight.Maasbanker iol differed from pilchard oil in that the percentage of C₂₀ unsaturated acids was lower and the percentage of C₂₂ unsturated acids was highere than in pilchard oil. A more striking difference was the lower degree of unsturation of both the C₂₀ and C₂₂ acids in the maasbanker oil; this was reflected in its very much lower iodine value.Cholesterol was the chief constituent of the unsaponifiable fraction of both pilchard and maasbanker oil. Other components of the unsaponifiable fractions of both oils were α‐glyceryl ethers, saturated and unsaturated hydrocarbons, fatty alcohols and vitamin A. Evidence was obtained that a C₂₂ unsturated fatty alcohol was present in the unsaponifiable faction of maasbanker oil.