Optimization of response surface methodology by D-optimal design for alkaline hydrolysis of crude palm kernel oil

• Main Authors: Murad Bahadi,, Mohamad Firdaus Yusoff,, Jumat Salimon,, Darfizzi Derawi,
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia 2020
• Online Access: http://journalarticle.ukm.my/14728/1/ARTIKEL%204.pdf; http://journalarticle.ukm.my/14728/; http://www.ukm.my/jsm/malay_journals/jilid49bil1_2020/KandunganJilid49Bil1_2020.html

Crude palm kernel oil (CPKO) was converted into its free fatty acids (FFAs) via alkaline hydrolysis. The reaction optimization was performed using Response Surface Methodology (RSM) through D-optimal design to optimize the conducted hydrolysis parameters. The optimization parameters were varied from 1.5 to 2.5 h of reaction time, 50-70°C of reaction temperature, and ethanolic KOH concentration 1-2 M. The highest percentage of free fatty acids was 98 ± 0.7 % with a percentage fatty acid yield of 84.7 ± 0.6 % under optimal conditions, which were 2.16 h of reaction time, 1.77 M ethanolic KOH concentration, and 70°C reaction temperature. High-temperature Capillary Column Gas Chromatography (GC-FID) and Nuclear Magnetic Resonance-Fourier Transform Infrared Spectroscopy (NMR-FTIR) were employed to characterize the product. The physicochemical properties of fatty acids were also tested. The acid value, iodine value, and hydroxyl value of the fatty acids obtained were 275.4 ± 0.7 mg NaOH/g, 21.8 ± 0.2 g I2 / 100 g, and 168.2 ± 0.1 mg KOH/g, respectively.