​Kernel Condition with Variations in Roasting Temperature on Yield and Quality of Candlenut Oil

Abstract

Background: Candlenut is one of the vegetable oil-producing plants as a source of biodiesel raw materials. One of the innovations is to increase the production and quality of candlenut oil by treating the kernels before roasting. Kernel condition (whole or fine powder) and roasting temperature affects and the oil production. This study aims to determine the condition of the kernel at various roasting temperatures on the production, yield and quality of the oil. Methods: Using a one-factor completely randomized design, kernel conditions with variations in roasting temperature consists of 7 (seven) levels, such as T0= Finely ground kernel, without roasting; T1= Whole kernel, roasted at 80°C for one hour, then mashed; T2= Whole kernel, roasted at 90°C for one hour, then mashed; T3= Whole kernel, roasted at 100°C for one hour, then mashed; T4= finely ground kernel, baked at 80°C for one hour; T5= Finely ground kernel, baked at 90°C for one hour; T6= Finely ground kernel, baked at 100°C for one hour. Each treatment was repeated 5 times and further tested with Duncan’s multiple range test at 0.01 level. Result: The results showed that the roasted fine powder kernels resulted in higher oil production, oil weight and oil yield compared to unroasted kernels and whole roasted kernels. The best results were found in finely ground kernels roasted at 90°C. The roasting temperature lowers the free fatty acid content of the oil, whole kernels produce lower free fatty acids than finely ground kernels. The lowest free fatty acids were found in whole kernels baked at 90°C.