January / February 2005 - CSIR

16ENZYMES PUT TO WORK IN THE PRODUCTION OFPECTIN FROM CITRUS WASTELIFElab ECoBio awards funding to improve competitiveness ofSouth African citrus producers through waste beneficiation.Biochemists at the CSIR are joining forces with the University of Durban-Westville, the Chemin incubator and Kat River Citrus Co-op Ltd to set upa pectin production plant that uses enzymes in the production of pectinsfrom citrus waste.LIFElab ECoBio is one of three Biotechnology Regional InnovationCentres (BRICS) set up in 2002 by the Department ofScience and Technology under the auspices of itsNational Biotechnology Strategy. LIFElab’smandate is to stimulate and promote thecreation of a vibrant biotechnologyeconomy in the East Coast region,stretching from Nelspruit in theNorth, to Durban in the centreand onwards to PortElizabeth in the South.The South African citrusindustry is one of thebiggest exporters inthe world and produceslarge volumesof waste in the formof citrus peel. Pectinis a polysaccharidefound abundantly inthe primary wallsand the intercellularlayers of plant cellsand is obtained froma variety of sourcesincluding many fruitpulps, for example inorange and apple pulp.In citrus fruit, pectin is aconstituent of the whitespongy inner part of thepeel. Traditionally, pectin isproduced by chemical hydrolysis,with significant yield lossesand the production of substantialwaste streams.Fanie Marais, Manager of Fine and SpecialityChemicals at the CSIR, says the extraction ofcrude high-methoxyl (HM) pectin from citrus peel is asimple downstream process that does not need specialisedchemicals or equipment. However, the first focus of this three-yearproject is to adapt the current HM pectin extraction process to enableSMMEs to operate the extraction facilities. The second focus, whichrepresents a significant opportunity for long-term sustainability, is toconvert HM pectin to value-added low-methoxyl(LM) pectin, using an enzyme-based process.“Recent years have seen strong growth in the LMpectin market. LM pectins are used as thickeningor gelling agents in a broad range of formulatedfoods such as yoghurt, milk desserts and jellies.Increasingly, pectin production facilities are beingmoved closer to citrus-producing areas to eliminatethe transport of dried citrus waste over longdistances and the resulting loss in yield andquality,” he says.These developments and a commitment to utilisebiotechnologies in South Africa’s bid to increaseits competitiveness, led to a decision by LIFElabECoBio to invest in research using the enzyme,called pectin esterase, to modify HM pectin intoLM pectin.Marais says the prototype development on theextraction of HM Pectin is well-advanced as aresult of earlier research. During the first phasesof the project, the focus will be on establishingsmall HM extraction plants that would be simpleto operate and be located in rural communitiesclose to orange juice producers. The aim is toproduce a range of stable, commercial quality HMpectins. At the same time, researchers at the CSIRwill focus on the development of an enzyme-basedprocess for the conversion of the HM pectin intohigher value LM pectin.The University of Durban-Westville will developdrying technology to ensure pectin production inthe off-season; Chemin will provide the businessincubation for a proposed spin-off company; whileKat River Co-op will provide the materials andfacilities for the first extraction facility. CSIR Food,Biological and Chemical Technologies will utiliseits skills in process chemistry, biotechnology,chemical engineering and food science to developthe technology required for the extraction, hydrolysis,purification and formulation.Enquiries: Michael BarkhuysenCSIR Food, Biological andChemical TechnologiesTel: +27 11 605 2330E-Mail: mbarkhuysen@csir.co.za