Abdul Rahman, Russly

Selamat, Jinap

Sheikh Abdul Hamid, Nazimah

Singh, Harcharan

Universiti Putra Malaysia Institutional Repository

Agricultural SciencesSupercritical Carbon Dioxide Extraction Of Cocoa Butter: Optimization OfOperating Conditions And Sample Matrix EffectJlnap Selamat. Harcharsn Sineh. RU51y Al7dul Rahman. and Nazlmah Sheikh Al7d. HamidFaculty of Food Science and BiotechnologyUniversiti Putra Malaysia43400 UPM, Serdang, SelangorMalaysiaTelephone Number of Corresponding Author: 03-89486314E-mailolCorrespondingAulhorjinap@pulra.upm.edu.myKey words: cocoa butter, extraction, supercritical carbon dioxide, RSM, sample matrixIntroductionCocoa butter, which is a yellowish white fat, is derived from the cocoa bean. After removing the shell from the bean, theremaining nib contains about 55% of cocoa butter. Unique to cocoa butter is its brittleness at room temperature and its quickand complete melting at body temperature. The special functional properties of cocoa butter make it indispensable in the food,cosmetic and pharmaceutical industries. In the food industry, cocoa butter is responsible for the smooth texture, mouth feel,flavour release and gloss of chocolate products. The customary methods of producing cocoa butter from cocoa liquor (finelyground cocoa nib) or cocoa bean at the present time are classified as hydraulic pressing. expeller pressing and solventextraction with organic solvents. However, there is an increasing awareness of the health and safety hazards associated withthe use of organic solvents; while pressing often introduces contaminants into the cocoa butter that must be removed later.These have placed new demand to develop clean and efficient technologies for obtaining cocoa butter. Supercritical fluidextraction (SFE). mainly by supercritieal carbon dioxide (SC-C02). has been studied as a potential alternative to the currentextraction method in vegetable oils extraction. The application of SC-C02 extraction otTers the advantages of rapid, nontoxicand contamination-free extraction, less destruction of thermally labile constituents, and prevents any possible oxidation in theoxygen free extraction condition. Attempts have also been made to produce cocoa butter by SFE technology. A patent on theefficient extraction of cocoa butter from cocoa liquor and cocoa nibs with CO2 in the pressure range from 25 to 35 MPa at atemperature between 45 and 60°C has been found. Nonetheless, other research has found that less than 5% of the cocoa buttercould be extracted from nibs, even if the extraction was carried out at 48.3 MPa for a period of8 hours at 40 to 60°C.JMaterials and MethodsMaterialsCocoa beans and cocoa liquor with minimum 52% fat content were obtained from KL-Kepong Cocoa Products Sdn. Bhd.,Malaysia. The cocoa liquor (particle size = 74 urn) was used without pre-treatment to study the optimization of operatingconditions. The cocoa beans were crushed and ground to obtain particle size ranging from 4 to 6 mm and 850 urn to J mm.Cocoa liquor, ground cocoa nibs and crushed cocoa nibs were then used to investigate the effect of sample matrix. The CO2was supplied by Malaysian Oxygen (MOX) Bhd., Malaysia. The chemicals and reagents used in the study were obtained fromFisher Scientific and Sigma Chemical Co, USA, which were analytical grade and high performance liquid chromatography(HPLC) grade. SFE Apparatus and Procedure: Extraction of cocoa butter was performed by SC-C02 extraction. The SFEapparatus consist of Intelligent HPLC Pump Model PU-J580 (Jasco Corporation. Japan) fitted with a cooling jacket to deliverCO2, In order to cool the pump head, ethylene glycol-deionized water mixture (50:50, v/v) was circulated through the coolingjacket using a Low Temperature Bath Circulator Model 63 ID (Tech-Lab Manufacturing Sdn. Bhd., Malaysia) which candeliver coolant down to -20°C. A 10 g sample was loaded into a SOrnL Extraction Vessel Model EV-3 (Jasco Corporation,Japan) that was placed in Column Oven Model CO-1560 (Jasco Corporation, Japan). The column oven was used to maintainthe extraction temperature. A Back Pressure Regulator (BPR) Model BP-1580-81 (Jasco Corporation, Japan) was used tocontrol the extraction pressure. A 10 ml test tube was used as collection vessel. The sample was extracted at pressure of I~5MPa, temperature of 35-75°C, extraction time ofO.5-4 h, and flow rate of2 mUmin.Experimental DesignThe optimization was carried out using response surface methodology (RSM). Pressure (P), temperature (T) and extractiontime (t) that were the important operating parameters involved in cocoa butter extraction using SC-C02, were the independentvariables. Three levels of each of the three variables were chosen and coded as -1 (lowest), 0 (middle) and 1 (highest). Foreach of the experiments done, the total fat content (%) was determined by gravimetry and triglyceride profile of cocoa butterwas determined by HPLC.Results and DiscussionOptimization of Operating ConditionsThe percentage of total fat content extracted by SC-C02 was greatly influenced by pressure, temperature and extraction time.Increment in pressure, temperature and extraction time up to 45 MPa. 750C and 4 hours gave the highest value of total fatcontent (31.89%). The lowest value of total fat content was observed at \0 MPa. 350C and 0.5 hour, with only 1.20%. TheetTects of pressure (P), temperature (T), extraction time (t) and interactions of P and t, T and t contribute significantly to theextraction efficiency of cocoa butter, with R2 of 0.985 and significance P values of O. The R2 more than 0.75 is statistically289UPM Research Report 1997-2000. Vol II. Section 2-Extended Abstractsconsidered accurate for developing a model or equation. In order to describe how the test variables affect the response, contourplots for response were generated by the RSM model using ECHIP software. The predicted total fat content (%) extracted bvSC-C02 as a function of pressure and temperature at constant extraction time of 0.5, 2.25 and 4 hours, respectively. Th~contour plots demonstrate that total fat content (%) increased with increasing pressure, temperature and extraction time. Thismay be due to the solubility of a given solute tends to increase with the operating pressure and temperature. Meanwhile, asexpected the total fat content (%) increased in longer extraction time. Optimum conditions of pressure, temperature andextraction time were determined by overlapping the contour plots and predict the optimum operating condition fromsuperimposed region of the three contour plots. It is apparent that optimum conditions for cocoa butter extraction bv SC -CO.are pressure, 45 MPa, temperature, 75°C, and extraction time, 4 hours, with 30.63% of predicted total fat content. 'Howe\"er~the practical limits of each variable are governed by different factors. Temperature must be kept below a level where thematerial begins to suffer thermal degradation. Pressure and extraction time are more related to economic considerations. asconstruction and operating costs increase with higher system pressure and longer extraction time. Response surfaces can alsobe visualized as three-dimensional plots by presenting the response in function of two factors and keeping the others constant.The response surface showed a strong degree of curvature, where the optimum can be readily determined (the point marked byarrow). The temperature had a weak influence on the yield of total fat content that indicate the less importance of this factor,while the pressure had a major effectThe EtTect of Sample MatrixThe rate of removal of a solute from a matrix using SFE is a function of its solubility in the fluid media and the rate of masstransport of the solute out of the sample matrix. The physical morphology of the sample matrix can have a profound effect onthe yield that obtained by SC-C02 extraction. The effect of sample matrix with different particle sizes on extraction of cocoabutter by SC-C02 at optimum conditions that had been obtained by optimizing the operating conditions. It is obvious that thesmaller the particle size of sample, the higher the total fat content will be extracted by SC-C02• This effect may be due to theshorter internal diffusional path lengths over which the extracted solutes must travel to reach the bulk fluid phase. Studies haveshown that the geometric size of the matrix particles can influence the speed and completeness with which a SFE can beconducted. Our results confirm the value reported by Rossi et al., who suggested that the low extraction yields observed fromthe nibs (particle size ranging from 2-4 mm) were caused by the lipid-bearing cells remaining intact in the nib, and concludedthat extraction of cocoa butter appears to be more of a leaching phenomenonTriglyceride profiles of cocoa butter extracted by SC-C02The etTects of various operating conditions namely pressure, temperature and extraction time to triglyceride profiles of cocoabutter extracted from cocoa liquor are given in Table 5. It can be seen that triglyceride profiles of cocoa butter extracted usingSC-C02 contain mono-unsaturated triglycerides (e.g. POP, POS, SOS, SOA and PLiP) and di-unsaturated triglycerides (e.g.,POO, PLiO). The results demonstrated POP (Cso), POS (Cn) and SOS (Cs~) were the major triglycerides in the extractedcocoa butter, whereby POS was the highest component which was more than 30% for all treatment. The sample matrix effecton triglyceride profiles of cocoa butter extracted using SC-C02 is shown that cocoa butter extracted from various samplematrix had similar triglyceride profile to that of typical cocoa butter.ConclusionsThe optimization of SC-C02 extraction of cocoa butter from cocoa liquor was measured as total fat content (%). as a functionof pressure, temperature and extraction time at constant flow rate. Increment in pressure, temperature and extraction timeincreased the total fat content (%) extracted from cocoa liquor. Pressure had a strong effect on the yield of total fat contentcompared to temperature. The optimum conditions for cocoa butter extraction using SC-C02 were 45 MPa. 75°C and 4 hours.Sample matrix had significant effect on SC-C02 extraction of cocoa butter. The results indicated POP (C5;), POS (Cd andSOS (C54) were the major triglycerides in the extracted cocoa butter, whereby POS was the highest component for alltreatments studied. The triglyceride profiles of the extracted cocoa butter complied with the typical triglyceride profile ofcocoa butter.Benefits from the studyMalaysia has been known to have high-melting point cocoa butter which is very much in demand by the world market. Thecurrent technology (hydraulic I screw press) being practiced by cocoa grinders is such that some of the cocoa butter is stillremained in the cocoa powder; the technology is capable of producing maximum of 10% fat-cocoa powder. Organic solventcan be used to extract all the cocoa butter in the powder; however the resultant powder cannot be used for human consumption.Furthermore, because cocoa powder is used mainly for beverages, the presence of the extra cocoa butter does not give anyadvantage (fatty drink is not preferred by customers) to the product. In this study Supercritical Fluid Extraction Technologywill used to extract the maximum level of fat from cocoa liquor or cocoa powder. However, fun her work 15 needed to optimizethe operating conditions, which may be the key to expanding the application of SC-C02 extraction on cocoa cuner extractionPatent(s), if applicable:Nil-Stage of Commercialization, if applicable:Nil-290Agricultural SCiencesProject Publications in Refereed Journals:NilProject Publications in Conference ProceedingsI Tan, T. J., Jinap, S. and Asep, E. K. (2002). Effects Of Temperature, Pressure And Extraction Time On Extraction Of Cocoa Butter FromCocoa Liquor Using Supercritical Carbon Dioxide. Oils and Fats International Congress 2002. Kuala Lumpur, Malaysia: 7-10 October,2002.2 Asep, E. K., Jlnap, S. and Tan, T. J. (2002). Effects of Particle Size, Fermentation and Roasting on Cocoa Butter Extraction UsingSupercritical Fluid Extraction Carbon Dioxide. Oils and Fats International Congress 2002. Kuala Lumpur, Malaysia: 7-10 October, 2002.3 Tan, T. J., Jlnap, S. and Asep, E. K., Harcharan, S., Rusly, A. R., Nazimah, S.A.H. (2002). Supercritical Carbon Dioxide Extraction OfCocoa Buller: Optimization of Operating Conditions And Sample Matrix Effect. Malaysian Science and Technology Congress 2002.Kuching, Sarawak, Malaysia: 12-14 December, 2002.Graduate ResearchNameGraduate---------------_._-_ .._------------of Research Topic Field of Expertise Degree Awarded Graduation YearAsep Edi Effect of sample Extraction of cocoa PhD On goingKusnadi preparation on butter bycocoa butter supercritical fluidextraction by extraction (SFE)supercritical fluidand modeling2 Tan TengJu Effect of co-solventon cocoa butterextraction bysupercritical fluidExtraction of cocoabutter bysupercritical fluidextraction (SFE)Master OngoingIRPA Project numberOl-02-04-0512UPM Research Cluster:AFF291

Supercritical carbon dioxide extraction of cocoa butter: optimization of operating conditions and sample matrix effect

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Supercritical carbon dioxide extraction of cocoa butter: optimization of operating conditions and sample matrix effect

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