Thermal properties of fats and oils

Abstract

Summary 1. Melting points and x‐ray diffraction patterns have been determined for cottonseed oil hydrogenated to an iodine value of less than 1, and for a very pure sample of tristearin. 2. Contrary to the observations of previous investigators, the x‐ray patterns indicate a well‐defined crystal structure with a sharp long spacing and a single sharp short spacing in the lowest‐melting form of tristearin. A new pattern, with two short spacings and a long spacing, was observed in tristearin of intermediate melting point. 3. Four polymorphic forms of the hydrogenated cottonseed oil were detected. The x‐ray pattern of the lowest‐melting form of the hydrogenated oil was similar to that of the correspopnding form of tristearin. The pattern of the highest‐melting form of the hydrogenated oil differed from that of either tristearin or β‐palmitodistearin, the major components of the oil. Distinctive patterns for the intermediate forms of the hydrogenated oil could not be obtained, presumably because of the instability of the lower melting forms at room temperature.

The Solubility of Tristearin in Organic Solvents.

“…"9•10 The other values indicate that the purity of the tristearin used in these experiments was equal to that reported elsewhere.9•10 The solubility curves in Figs. [4][5][6][7] show that tristearin is more soluble in the non-polar solvents than in those of higher polarity. It is somewhat more soluble in the chlorinated hydrocarbons than in hexane or benzene.…”

The Polymorphism of Glycerides.

“…As a result of X-ray investigations Malkin and colleagues (30,78) demonstrated conclusively that the basis of the multiple melting behavior was actually polymorphism, i.e., the occurrence for a given compound of different crystalline forms distinguishable by X-ray diffraction pattern (40). Later workers (7,46,68) came to conclusion that there was an error in this association of melting points with X-ray diffraction patterns. Lutton (72), in particular, was particularly prominent in this assertion.…”

Mathematical expressions for calculation of oil‐polymer blends

“…Taking the values of e of safflower, palm and peanut oils from the literature [8,9] and the reported values of M and r from Tab. 3, we have calculated the molar polarizations of the oils.…”

“…The dielectric constants of safflower, palm and peanut oils taken from the literature [8,9] are 2.476, 2 469 and 3.100, respectively.…”