Abstract
To investigate the physical characteristics of recent household margarines, 19 brands of margarine and 6 brands of fat spread were measured for their hardness index by cone-penetration, hardness (R) by a Reometer, oil-off value, solid fat content (SFC), open-tubed melting point (EMP) and softening point by JIS (ESP) and clear point (MCP), dropping point (MDP) and softening point (MSP) by Elex and Mettler automatic melting point apparatus.
1) The hardness of margarine decreased in the order of high linoleic soft>common soft>carton hard>parchment hard. Fat spread tended to be softer than the soft margarine, but to soften more slowly with increase in temperature. No difference was observed in their softeess at 20°C or higher. Softer margarines tended to oil-off more easily and showed less SFC. However, although fat spread was softer, it showed greater SFC and less oil-off value than the soft margarine.
2) In MDP and MSP, few differences were observed in measurements on the product and oil phase. The former for fat spread clearly exceeded that of the latter.
3) Oil-off values were correlated with hardness indexes, but tended to scatter in a softer region of the hardness index greater than 200. The relationship of hardness (R) to oil-off value could be expressed as a hyperbola, indicating the latter to be lower than 1% at a hardness (R) exceeding 1000 and to rapidly increase at a hardness less than 200.
4) The hardness index and SFC at 10°C were correlated with total % of saturated fatty acid plus trans-18 : 1, and with total % of unsaturated fatty acid except trans-18 : 1. However, both values were closely correlated with total % of polyunsaturated fatty acid (18 : 2+18 : 3).
