Abdullah, Dzulkefly Kuang

Olobo, Obaje J.

Universiti Putra Malaysia Institutional Repository

FOR Category Fl0300: Chemical SciencesSYTNTHESIS AND CHARACTERISATION OFGLUCOSE ESTERS OF PALM OIL AND PALM OILPRODUCTSDzulkefly Kuang Abdullah and Obaje J. OloboFaculty of Science and Enviromnenwl StudiesUnivcrsiti l'utTll Mala,sia. 43400 UI'M. SerJanK. Selans:or.Mala:ysiaKeywords: palm oil. glucose esters. interesterification,nonionic surfactant.IntroductionCarbohydrate fatty esters have been shown to have goodprospect as surfactants (Bobalek, 1977; De Luca et al. 1997;Ducret et al. 1995) but to produce food quality carbohydratefatty esters in commercial quantities has remained a bigchallenge. This is because the condensation reaction be-tween the carbohydrates and fatty acids is beset with prob-lems: (i) the two substrates are not mutually soluble; (ii)known mutual soluble solvents are toxic; and (iii) the sub-strates are rarely stable at the temperatures required for thereaction to occur. In order to circumvent these problems wehave adopted a solvent-free interesterification process (Akohand Swanson. 1990) to produce acetylated glucose fatly es-ters at relatively low temperatures and in good yield.Structural analysis. e.g. TLC. FT-IR. IJI- and 13C-NMRhave shown the products to be mainly mono-substituents.The objective of this project therefore was to find a reactionprocess that can produce food quality. glucose fatty esters ingood yield.Materials and MethodsGlucose pentaacetate, GPA (99% pure) was purchased fromFluka Biochernica FAME of PO and PKO. stearic and oleicacids were gifts fromHenkel Oleochemical. Malaysia. BuchsSilica gel 60 (particle sire O.063-0.200mm. 70-230 meshASTM) and pre-coated silica gel 60 F2S4 TLC plates wereobtained from E. Merk (Darmstadt. Germany). All solventsused were of analytical grade and obtained from E. Merck(Darmstadt Germany).Appropriate fatty acid methyl ester (FAME) was put in athree-necked. round-bottom flask equipped with a magneticstirrer. stopcocks. vacuum take-off line leading to liquid ni-trogen cold-trap and a vacuum pump. TIle reaction flask wasflushed with dry N2 ga.~ for 30 minutes before admixing thereactants. GPA (S.Ommol) and sodium metal (0.12g) wereadded and heating commenced with continuous stirring. Anoil bath was used to maintain the temperature between KOand 105°C. The reaction was continued for 4 to 5 hours.The product was neutrali~ with l-~ml glacial acetic a.cid.allowed to cool. dissolved In acetOnitrile and decolourlsedwith 2g of activated charcoal. The glucose fatty-acid esterswere purified by separation on a 40x2 cm slurry packed col-umn (packed with silica gel 60. particle size 0.06J-().200mm;70-230 mesh ASTM). The products were eluted with 10%ethyl acetate in hexane. The ethyl acetate and hexane wereevaporated by rotary evaporation to give the products. Glu-cose esters of palm oil palm kernel oil. stearic and oleic acidswere prepared in the same manner.Results and DiscussionMolecular Structure of product was confirmed from ll-andIlC-NMR. corroborated with f'T-IR spectra. The relative po-sition of the acyl group on the pyranosyl ring was determinedfrom the relative Spprn shifts of the C ..O carbon (16K.91-170.9K in I)C-NMR). resulting from the shielding effect ofthe long-chain alkyl group compared to the methyl group inthe acetate. For the product. I-O-acyl-2.3.4.6-tetraacetyl-a-Dvghrcopyranose, the C=O linked to Cl gives a O(ppm) of0.10 relative to the O(ppm) of the equivalent in GPA and it isthe largest displacement in the class. The intercsteriflcationreaction was found to be most effective at temperatures be-tween RO"C and 9(tC. 1-20 mUg pressure and mole ration ofGPA: FAME I :3. The yields obtained were between 60-63%. The reduction of surface tension from 72 dynes/cm inde-ionised water to about 3K dynes/cm for these compoundsdemonstrates their potential as surfactant molecules.ConclusionsInterseterification provides a convenient route to the produc-tion of glucose Iatty acid esters without the use of solvents.The reaction products. mono fally-esters of glucose acetate.are potential surfactant ingredients in food. cosmetics, phar-maceutical and other industries. The acetate group attachedto glucose is a good leaving and protective group and. at thesame time, enhances the solubility for tne glucose moiety infatty acid methyl ester (FAME). The yield can he further in-creased through optimisation of this process.ReferencesAkoh, C.C. lind Swanson, R.G. 19<)(J.Oplillli/cd xynthcvis of SUCf"'Cpolyesters: Comparison of physical properties of sucrose polycs-ters, raffinose polyesters and salad oils. 1. F"od Sd. SS( I): 2.16·243.Bobalek, E.G. 19n. I'ro~pcl:t' and potcnnal for commercial produc-lion and utilization or SUI:rtl.'C fillly acid esters. In "Sucrochrm-istry" R.t'. Gould (Ed.), American Chemical Sudety. Washing·ton. DC. p. 162.De Luca, D .. De Nino. A., Liguori. A .• I'ro.:opio. A. lind Sindona, G.19')7. Nonionic surtactants: Regioselcctive synthesis of fally ac-id. esters of u-and II·gluwpyranose. Lipids. ~2: SW·~63.Ducret, A .• Giroux, A., Trani. M. and Lortie, R. IlJI)~. Enzymaticpreparation of lIinsurfactanls rrom sugar alcohol. and (ally acid .•in organic media under reduced pressure. Blottch. lliofnJ(. 4HO):214-221.SUl'poNt'd by /HPJ. Grunt 0/·02-04·0070239

Sytnthesis and characterisation of glucose esters of palm oil and palm oil products

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Sytnthesis and characterisation of glucose esters of palm oil and palm oil products

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