Penentuan Karakteristik Termofisik Bawang Merah (Allium cepa var.ascalonicum)

Abstract

Information about thermo-physical properties of red onion are needed to know to optimize post-harvest treatment of onions both cooling and drying, as well as to optimize the use of energy during the post-harvest process. The study was to determine the thermo-physical properties of red onion (leaves and tubers) which consist of water content, thermal diffusivity, thermal conductivity, density, and specific heat as well as to obtain a mathematical equation model of the water content towards the thermo-physical properties of red onion. Drying leaves and onion tubers for 6 days obtained in specific heat values, thermal conductivity and density which were proportional to the decrease in the material water content, especially on the dehydration process of red onion leaves. Red onion thermal diffusivity was determined using a numerical method of cooling temperature data of onion tubers which produce data thermal diffusivity 1.433 x 10-8 m2/s with a mean accuracy average of 93.37%.