Optimization of Rubber Seed (Hevea brasiliensis) Drying in Rubber Seed Oil Extraction for Chamois Leather Tanning

Abstract

Drying is one of the important steps in oil extraction using mechanical pressing. /t can decrease oil hydrolysis and increase yield of oil due to the decrease of oil affinity on the material surface and protein coagulation. Therefore. the oil will be released easily from seed in the oil extraction using the hydraulic pressing. Objectives ofthis research were to determine a combination oftemperature and duration ofdrying of rubber seed prior to oil extraction in order to produce oil with the best yield and phYSico-chemical properties for chamois leather lanning. and to observe the potency ofthe rubber seed oil as a leather tanning agent. This research consisted ofsort at ion ofrubber seed, rubber seed drying using an oven, oil extraction using a hydraulic pressing. and analysis ofphysicochemical properties ofthe oil and residue ofrubber seed after extracting its oi/. Results of the research shows that the higher temperature and duration of rubber seed drying, the higher oil content in residue and colour ofthe oil, whereas yield, iodine number. acid number, fi'ee-fatty acid content ofthe oil, as well as water content ofthe rubber seed decreased. Based on-the highest ofyield and iodine number, the best treatment for the rubber seed drying was drying at 7ife for one hour. This condition resulted in oil with physico-chemical characteristics ofoil: yield of20.52%, colour of 4077 PtCo unit; density of0.924, viscosity of 160 centipoises, iodine number of 146, acid number of2.08, FFA of 1.04 %, saponification number of /84.58, and peroxide number of 30.46. The treatment gave oil content in the residue of 9.84 %. The rubber seed oil was potential for substitutingfish oil as tanning agent. as it had iodine number ofhigher than 120.