Qualitative Evaluation of Oils and Fats by the Thermogravimetry.V.

Thermal Weight Reduction Behaviors of Household Margarines

Abstract

The thermal weight reduction characteristics of household margarines were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC).
1) The weight reduction behavior of margarines with aqueous vaporization was observed to vary with the type of sample. In particular, aqueous vaporization in the type of margarine containing gas, or high content of water and protein was noted to start at lower temperature than that of the other types.
2) The pyrolysis behavior of margarines after dehydration varied with the type of sample. In the case of the high linoleic soft type, weight gain with absorption of oxygen was observed and weight reduction in temperature range from 300°C to 400°C was slower than that of other types. TG curve of butter fat containing fat spread was more simple than those of the above samples. However, weight reduction appeared essentially the same in common soft and carton hard margarines since their fatty acid compositions were similar.
3) The rate of weight reduction by the end of the isothermal step at 110°C was correlated to moisture content. From 250°C to 350°C, it was also correlated to the iodine value.