1978 年 27 巻 3 号 p. 165-168
With four kinds of solid edible fats and fats with different degree of hardening, melting curves were measured by the Mettler automatic melting point apparatus, Model FP-5/FP-51, and clear melting points (MCP) were calculated from the curves. Comparative examination with other methods of measurements was made, especially on the clear point (CP) and the open-capillary melting point (OMP), and the following results were obtained.
1) The observed values of MCP tended to be higher with higher heating rate but the values agreed with those of CP when the heating rate was 0.2 and 1°C/min, and the dispersion of observed values was smaller. Difference between MCP and OMP tended to become smaller as the melting curve at the end of melting became sharper.
2) Melting curve at the end of melting of soybean oil and fish oil, with low degree of hardening, showed a tailing, almost in parallel with the base line, and the difference of MCP from CP and OMP became slightly greater, and the dispersion of observed values was greater. Inversely, in the case of hardened coconut oil, this difference of MCP from CP and OMP, and the dispersion of observed values became greater as the degree of hardening became greater.
3) There was a high correlation between MCP and CP and OMP, and MCP seemed to be sufficiently practicable for use as the melting point of solid fats.