Sains Malaysiana 41(6)(2012): 731–738

D-Optimal Design Optimization of Jatropha curcas L. Seed OilHydrolysis via

Alkali-Catalyzed Reactions

(Pengoptimuman Reka Bentuk D-Optimum Hidrolisis Minyak Biji Jatropha curcas L.

Melalui Tindak Balas Mangkin Alkali)

Jumat Salimon*, B Asharmudhaffar Abdullah & Nadia Salih

School of Chemical Sciences and Food Technology, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

Diserahkan: 11 Oktober 2010 / Diterima: 20 Januari 2012

ABSTRACT

Potassium hydroxide (KOH)-catalyzed reactions were utilized to hydrolyze Jatropha curcas seed oil. In this study, the effect of ethanolic KOH concentration, reaction temperature and reaction time to the free fatty acid (FFA) produced were investigated. D-Optimal Design was employed to study the significance of these factors and optimum conditions for the technique was predicted. The results showed that ethanolic KOH concentration was a significant variable for hydrolysis of J. curcas seed oil. In 18 experimental designs, FFA percentage of hydrolyzed J. curcas seed oil increased from 1.89% to 102.2%. The optimal conditions of response were found at 1.75M of ethanolic KOH, 65 °C and at 2 h reaction time. Fourier Transforms Infrared Spectroscopy (FTIR) spectrum analysis confirmed the concentration of ethanolic KOH i.e. at 1.00, 1.50 dan 1.75 M affect the percentage yields of J. curcas seed oil hydrolysis process.

Keywords: Alkaline hydrolysis; D-optimal design; Jatropha curcas seed oil

ABSTRAK

Tindak balas bermangkin kalium hidroksida (KOH) telah digunakan untuk hidrolisis minyak biji Jatropha curcas. Kesan nisbah kepekatan KOH beretanol, suhu dan masa tindak balas terhadap penghasilan asid lemak bebas (ALB) telah dikaji. Reka bentuk D-Optimum telah digunakan untuk menentukan keberkesanan parameter tindak balas dan nilai optimumnya diramalankan serta ditentukan. Keputusan kajian menunjukkan bahwa kepekatan KOH beretanol merupakan parameter yang bererti bagi hidrolisis minyak J. curcas. Reka bentuk 18 uji kaji menunjukkan peratus ALB hasil hidrolisis minyak J. curcas telah ditingkatkan daripada 1.89% kepada 102.2%. Keadaan gerak balas optimum telah dicerap pada 1.75 M KOH beretanol, suhu 65°C dan 2 jam masa tindak balas. Analisis Spektroskopi Inframerah Fourier Transform (FTIR) telah membuktikan bahwa pertambahan kepekatan KOH beretanol pada 1.00, 1.50 dan 1.75 M meningkatkan peratusan hasil proses hidrolisis minyak biji J. curcas.

Kata kunci: Hidrolisis beralkali; minyak biji; reka bentuk D-optimal; Jatropha curcas

RUJUKAN

Ackelsberg, O.J. 1958. Fat splitting. Journal of the American Oil Chemists’ Society 35: 635-640.

Bashar, M.A. & Jumat, S. 2009. Physicochemical characteristics of Malaysian rubber (Hevea Brasiliensis) seed oil. European Journal of Scientific Research 31: 437-445.

Carvalho, P.D.O., Campos, P.R.B., Noffs, M.D., Fregolente, P.B.L. & Fregolente, L.V. 2009. Enzymatic hydrolysis of salmon oil by native lipases: optimization of process parameters. Journal of the Brazilian Chemical Society20: 117-124.

Fadiloğlu, S. & Söylemez, Z. 1998. Olive oil hydrolysis by celite-immobilized Candida rugosa lipase. Journal of Agricultural and Food Chemistry 46: 3411-3414.

Hermansyah, H.K., Shibasaki-Kitakawa, N. M. & Yonemoto, T. 2006. Mathematical model for stepwise hydrolysis of triolein using Candida rugosa lipase in biphasic oil-water system. Biochemical Engineering Journal 31: 125-132.

Jumat, S., Mamot, S., Suria, R. and Mohamad Azwani, M.L. 2006. Oils and Fats Analysis. Bangi: Penerbit UKM.

Jumat, S. & Rozaini, A. 2008. Physicochemical properties of Malaysian Jatropha curcas seed oil. Sains Malaysiana37: 379-382.

Mason, R.L. Gunst, R.F., Hess, J.L. 1989. Statistical Design and Analysis of Experiments with Applications to Engineering and Science. New York: Wiley.

Noor, I.M., Hasan, M. & Ramachandran, K.B. 2003. Effect of operating variable on the hydrolysis rate of palm oil by lipase. Process Biochemistry 39: 13-20.

Pinto, J.S. & Lanças, F.M. 2006. Hydrolysis of corn oil using subcritical water. Journal of the Brazilian Chemical Society 17: 85-89.

Rooney, D. & Weatherly, L.R. 2001. The effect of reaction conditions upon lipase catalysed hydrolysis of high oleate sunflower oil in a stirred liquid-liquid reactor. Process Biochemistry 36: 947-953.

Senanayake, J.N. & Shahidi, F. 1999. Enzymatic incorporation of docosahexaenoic acid into borage oil. Journal of the American Oil Chemists’ Society 76: 1009-1015.

Serri, N.A., Kamarudin, A.H. & Abdul Rahaman, S.N. 2008. Preliminary studies for production of fatty acids from hydrolysis of cooking palm oil using C. rugosa lipase. Journal of Physical Science 19: 79-88.

Socrates, G. 2001. Infrared and Raman Characteristic Group Frequencies: Tables and Charts. (3rd ed). Chichester, England: John Wily & Sons Ltd.

Syed Rahmatullah, M.S.K., Shukla, V.K. & Mukherjee, K.D. 1994. γ-Linolenic acid concentrates from borage and evening primrose oil fatty acids via Lipase-Catalyzed Esterification. Journal of the American Oil Chemists’ Society 71: 563-567.

Wu, M. D., Wang, H.S. & Xu, S.H. 2008. Optimization conditions for the purification of linoleic acid from sunflower oil by urea complex fractionation. Journal of the American Oil Chemists’ Society 85: 677-684.

Yang, K. & El-Haik, B.S. 2009. Design for Six Sigma, Roadmap for Product Development. (2nd Ed). New York: McGraw-Hill Professional.

*Pengarang surat-menyurat; e-mail: jumat@ukm.my