Abstract
Using a conduction calorimeter, the authors measured enthalpy changes of foods and gelatin models in the temperature range from -40° to 20°C.
The effect of water and solute contents on enthalpy of foods was conspicuous from the measurements of enthalpy.
The following relations between enthalpy (H, kJ·kg-1) and water contents (w, weight fraction) were obtained from the data of model foods to propose a method of estimating enthalpy of foods.
H(293)=442w+45
H(mp)=428w-21
H(253)=39
H(243)=18
When these equations were used to estimate enthalpy of 30 foods whose experimental data were already reported, it was confirmed that the method was simple and accurate regardless of kinds of foods. The method can be applied to the foods whose water contents are more than 40% and fat contents are less than 10%.
The effect of melting of fats was conspicuous in various heats which were related to the estimated enthalpy.
