Sri Handayani

Enzymatic Synthesis of Glyserol-Coconut Oil Fatty Acid and Glycerol-Decanoic Acis Ester as Emulsifier and Antimicrobial Agents Using Candida rugosa Lipase EC 3.1.1.3

In this research, enzymatic esterification was carried out between glycerol and fatty acid from coconut oil and decanoic acid using n-hexane as solvent. In this reaction Candida rugosa lipase was used as biocatalyst. Optimization esterification reaction was carried out for parameter of the substrate ratio. The mmol ratio between fatty acid and glycerol were used are 1:1, 1:2, 1:3, and 1: 4. The highest conversion percentage obtained at the mole ratio of 1: 4 with the value of 78.5% for the glycerol-decanoic acid ester and 55.4% for the glycerol coconut oil fatty acid ester. Esterification products were characterized by FT-IR. The FT-IR spectrum showed that the ester bond was formed as indicated by the wave number 1750-1739 cm−1. The esterification products were then examined by simple emulsion test and was proved to be an emulsifier. The glycerol-coconut oil fatty acid ester produced higher stability emulsion compare with glycerol decanoic ester. The antimicrobial activity assay using disc diffusion method showed that both glycerol-coconut oil fatty acid ester and glycerol-decanoic ester had the ability inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis. Glycerol-decanoic ester shows higher antimicrobial activity than glycerol-coconut oil fatty acid ester.

Interesterification of palm oil by using immobilized Candida rugosa lipase on Fe3O4-polydopamine nanoparticles

In this research, Candida rugosa lipase was used to produce fatty acid alkyl ester by interesterification reaction of palm oil with ethyl acetate or propyl acetate. The covalent immobilization of lipase on Fe3O4-polydopamine nanoparticles was prepared by coprecipitation methods. Magnetite (Fe3O4) was used in lipase immobilization because of its binding efficiency and selective separation under a magnetic field. The immobilized lipase and Fe3O4-polydopamine nanoparticles were characterized using FTIR, XRD, and FESEM-EDS. Immobilized lipase has 84.8% of loading percentage and 3.67 U/mg of specific activity, while free lipase has 13.09 U/mg of specific activity. All sample showed the high composition percentage of oleic acid alkyl ester. Conversion percentage of fatty acid ethyl ester from free and immobilized were 17.48% and 9.93%. Conversion percentage of fatty acid propyl ester from free lipase and immobilized lipase were 11.57% and 9.88%. Immobilized lipase on Fe3O4-polydopamine nanoparticles could be us...

The effect of different organic solvents on ethyl oleate from palm oil transesterification using immobilized Candida rugosa lipase on Fe3O4-polydopamine nanoparticles

Ethyl oleate ester can be produced by palm oil transesterification. Enzymatic transesterification reaction can be performed by using immobilized Candida rugosa lipase on Fe3O4-polydopamine. The obtained loading percentage of immobilized lipase was 78%. Fe3O4-polydopamine nanoparticles was succesfully characterized using FE-SEM, VSM, and XRD. Variation of solvents used for reaction were t-butanol, methyl isobutyl ketone, and n-hexane. Analysis of ethyl oleate ester was performed by GC-FID. The highest composition on transesterification using free lipase and immobilized lipase, with methyl isobutyl ketone as solvent, were 80% and 54%, respectively. Immobilized enzyme in this reaction can be used repeatedly for three reation cycles reaction with a relative activity decrease of 61%.