Continuously increasing of unsaturation level of crude palm oil using fermentation broth of Absidia corymbifera Peningkatan ketidakjenuhan minyak sawit kasar secara kontinyu menggunakan cairan fermentasi Absidia corymbifera - . TRI-PANJI (INDONESIAN OIL PALM RESEARCH INSTITUTE, 2000)
Ringkasan Absidia corymbifera merupakan fungi penghasil asam lemak takjenuh majemuk yaitu asam linoleat dan asam y-linolenat. Produksi asam lemak jenis ini berkaitan dengan aktivitas enzim desaturase yang terdapat balk di dalam sel maupun di dalam cairan fermentasi (di luar sel). Enzim ini berpotensi untuk dimanfaatkan dalam biokonversi enzimatik guna meningkatkan ketidakjenuhan minyak sawit kasar (CPO). Penelitian ini bertujuan meningkatkan ketidakjenuhan minyak sawit kasar melalui biokonversi enzimatis secara kontinyu menggunakan cairan fermentasi Absidia corymbifera Pertama, fungi ini dikulturkan dalam media cair mengandung CPO dengan suplemen garam tertentu menggunakan bioreaktor film permukaan. Setelah inkubasi, biomassa fungi disaring dan sisa CPO dipisahkan. Cairan fermentasi diisikan ke dalam kolom gelas dan CPO dipompakan dari bagian bawah kolom menggunakan pompa peristaltik Analisis komposisi asam lemak dilakukan terhadap CPO sebelum dan setelah biokonversi serta terhadap lipid biomassa. Karakterisasi lipid dilakukan terhadap CPO sebelum dan setelah biokonversi, meliputi angka asam, angka iod, dan angka penyabunan. Hasil penelitian menunjukkan bahwa cairan fermentasi A. corymbifera mampu meningkatkan ketidakjenuhan CPO dan kandungan asam lemak talfenuh majemuk Peningkatan ketidakjenuhan berkurang selama proses biokonversi kontinyu yang diduga disebabkan menurunnya aktivitas enzim desaturase. Angka asam dan angka penyabunan tidak meningkat secara nyata yang menunjukkan bahwa pada proses tersebut tidak terjadi pemecahan gliserida dari CPO.Summary Absidia corymbifera is a fungus producing polyunsaturated fatty acids (PUFA), namely linoleic and y-linolenic acids. Production of these kind of fatty acids is related to the acitivity of desaturase enzyme existing both inside and outside cell (in fermentation broth). This enzyme is potential to be used in enzymatic bioconversion for increasing unsaturation level of crude palm oil (CPO). The objective of this research was to increase unsaturation level of CPO through continuous enzymatic bioconversion using fermentation broth of A. corymbifera. This fungus was firstly cultured on a media containing CPO supplemented with certain salts using surface film bioreactor. After incubation, fungal biomass was filtered and residual CPO was then separated. Fermentation broth was filled to a glass column and CPO was pumped from the bottom side of the column using a peristaltic pump. Analysis of fatty acid composition was carried out on CPO before and after bioconversion as well as to lipid biomass. Lipid characterization was carried out for CPO before and after bioconversion, including acid, iodine and saponification numbers. The results showed that fermentation broth of A. corymbifera was capable of increasing unsaturation level CPO and the content of polyunsaturated fatty acids. Desaturation process decreased during bioconversion which was possibly caused by the decrease of activity of desaturase enzyme. Acid and saponification numbers did not increase significantly, indicated that hydrolysis glyceride of CPO did not occur.