Determination of the Specific Heat Capacity of Local Cooking Oils Using a Calorimetric Method

Specific heat capacity is a thermodynamic property that determines the amount of energy required to raise the temperature of a substance, with direct implications for cooking energy efficiency and food processing design. This study determines the specific heat capacity of five local cooking oils commonly consumed in Nigeria, including palm oil, groundnut oil, soybean oil, coconut oil, and shea butter oil, using an electrical calorimeter method. All samples were sourced from local markets in Minna, Niger State, North Central Nigeria. The electrical calorimeter consisted of a polished copper calorimeter fitted with an electrical heating coil, thermometer, and stirrer, calibrated using water as a reference standard. Measurements were conducted at initial temperatures of 25 degrees Celsius and 40 degrees Celsius to assess temperature dependence of specific heat capacity. Results indicate specific heat capacity values ranging from 1.68 J/g-K for palm oil to 2.12 J/g-K for coconut oil at 25 degrees Celsius, consistent with published literature ranges for vegetable oils. Shea butter oil recorded the highest temperature sensitivity, showing a 6.4 percent increase in specific heat capacity between 25 and 40 degrees Celsius. The study relates observed variations to differences in fatty acid chain length and degree of unsaturation among the oil types. Findings have practical implications for improving energy efficiency in commercial deep-frying operations and for the design of solar thermal cooking systems. Keywords: specific heat capacity, cooking oils, calorimetry, Minna, thermal properties