1, 3-二飽和アシル-2-オレオイルグリセリン混合系の多形現象
POP, POS, SOS
1989 年 38 巻 4 号 p. 306-311
詳細
1989 年 38 巻 4 号 p. 306-311
The polymorphism of mixtures of POP, POS and SOS was analyzed by using samples composed of pure compounds (>99%). Three mixture systems were prepared, A : POP (18.2%), SOS (34.0%), POS (47.8%), B : POP (44.5%), SOS (39.2%), POS (16.3%) and C : POP (58.1%), SOS (41.9%). The presence of polymorphism and its thermal transformation were examined by X-ray diffraction (XRD) and DSC, both applicable to the same sample at the same time, The three mixture systems exhibited almost identical polymorphic behavior : namely, α, pseudo-β', β2 and β1 occurred either via melt crystallizaion or polymorphic transformation. Melting points increased in the order, α to β1. In mixture C, the γ form was also detectable, with its melting point lying between those of α and pseudo β.
The transformation rates from β2 to β1 were highest in mixture C, and slowest in mixture A.
Both XRD short spacing patterns and DSC melting behavior of β2 and β1 of the three mix-tures were completely identical to those of pure POP and SOS, and to Forms V and VI of cocoa butter. Since mixture A has the same triacylglycerol composition as cocoa butter, the conversion from Form V to Form VI may be concluded to be the same as a solid-state-transformation.
