Optimasi Suhu Dan Lama Inkubasi Pada Hidrolisis In Situ Minyak Jarak Pagar Untuk Produksi Surfaktan Mono- Dan Digliserida

Abstract

The increasing of people population in the world and also the increasing of technology development can support the invention of human need products. Surfactant is a component that can be used as mixing solution for many products. Its amphiphilic character can be used widely in many applications and have increasing usage for each year. Surfactant production based on vegetable oil such as mono- and diglyceride can be obtained from Jatropha oil because it has high productivity and high vegetable oil component. Effective and efficient method to produce mono- and diglyceride can be done with in situ hydrolysis method that is affected by temperature and incubation time. The research purposes are to obtain the effect of temperature and incubation time of Jatropha seed on in situ hydrolysis on surface tension, interfacial tension, emulsion stability, acid value, saponification value, and refractive index parameter, and also to determine optimum condition of physical characteristic of the surfactant (surface tension). The eksperimental design of this research is two level factorial design with two factors, wich were temperature and incubation time. The lowest temperature of incubation is at 33○C and incubation time of 3 days, the highest temperature of incubation is at 37○C and incubation time of 7 days. Meanwhile, the method used to find optimum condition is Response Surface Method. Surfactant M-DG that was produced can decrease water surface tension of 34−40 dyne/cm. It has interfacial tension value about 8−12 dyne/cm, emulsion stability of 48.1−59.49%, acid value of 25.81−67.11 mg KOH/g of oil, saponification value of 135.38−199.57 mg KOH/g of oil, and refractive index about 1.3777−1.4762. The microbiological analysis showed the increasing number of Mucor sp., the producer of lipase 1,3-regiospecific in Jatropha seed after incubation process. Based on the statistical analysis of factors involved, it can be concluded that incubation temperature has negative correlation to surface tension (93.87%), interfacial tension (93.79%), acid value (82.61%), and refractive index (63.93%). It has positive correlation to emulsion stability (92.72%) and saponification value (99.23%). The incubation time has negative correlation to surface tension (92.64%), interfacial tension (89.67%), and refractive index (65.76%), and has positive correlation to emulsion stability (69.98%), saponification value (97.67%), and acid value (96.77%). From Response Surface Method analysis, it can be obtained at the best condition to decrease surface tension to a minimum value of 33.42 dyne/cm with incubation temperature at 36.11○C and incubation time of 7.32 days.