Selamat, Jinap

Universiti Putra Malaysia Institutional Repository

FOR Category F10900: Agricultural SciencesMECHANISM OF FAT MIGRATION OF LAURICHARD BUTTER (PKS) AND NON LAURIC FAT (PMF)BASED FILLING CENTRE IN DARK CHOCHOLATEJinap SelamatFaculty of Food Science and BiotechnologyUniversiti Putra Malaysia, 43400 UPM, Serdang, Selangor,MalaysiaKeywords: chocolate, lauric, migration, bloom, non-lauric.IntroductionMalaysia is the leading country in palm oil and palm kerneloil production. These fats are fractionated into liquid oleinsand hard stearins (palm mid fraction and palm kernelstearin), the latter was used as the base filling center inchocolate. In warm seasons (Malaysian range temperature25-30°C), these fats tend to migrate from the base center intothe coating, due to the presence of short fatty acids or tri-glyceride and/or unsaturated fatty acids and low m.p. Thismigration causes the chocolate stickiness and softness, whichconsequently, leads to changes in the cocoa butter crystalsand bloom formation. This phenomenon will affect Malay-sian chocolate in the international market. Therefore, the ob-jectives of our study were: To study the mechanism of PKSand PMF migration into the chocolate surface; to determinethe effect of desiccated coconut on the rate of migration ofPKS and PMF migration; to study the effect of different stor-age temperatures on the rate of fat migration and the poly-morphic changes in cocoa butter due to fat migration. Themain goal of this study was to find a way to improve theshelf life of .local Malaysian chocolates.Materials and MethodsThe fat migration was stimulated in real product by usinglayers of cream filling and dark chocolates approximatelyl00g each in a plastic box of 200g size. Two types of fillingwere prepared, Fl (30% palm kernel stearin, 70% icingsugar), and F2 (30% palm kernel stearin, 15% desiccated co-conut and 55% icing sugar). For the coating section darkchocolate was used. Samples were stored at 30°C for 8weeksto study the mechanism of PMF and PKS migration. For theeffect of temperature on fat migration, the samples werestored at 35°C and 18°C for the same period. Each week in-terval, chocolate was be separated and dissected into 3, 6, 9,12 and 15mm to study the physiochemical properties of thedark chocolate using Texture analyser for hardness, Humid-ity chamber for bloom, DSC for melting point, NMR for SFCand X-ray for polymorphic changes and the chemical testssoxhlet apparatus for total fat content, GC for FAME andHPLC for TGs.Results and DiscussionHardness decreased with the increasing storage time and in-crease with the increase in distance. Chocolate filled with F2was substantially softer than those filled with Fl. This couldbe due to the presence of coconut oil in F2. An increase in theamount of liquid phase resulted in softer chocolate (Dimickand Manning, 1987). In F2, very low SFC (5 and 10%) wasobserved at 3mm and 6mm distance at 30°C after 5 weeksstorage period respectively. This could be due to the incom-patibility between lauric fats and CB (Herzing, 1989). DSCmelting profiles show two distinct peaks in both cases, thiscomplex melting behavior occurred in the region of dilutioneffect (SFC%). Dark chocolate filled with F( (harder) bloom4 cycles faster than those filled with F2 (softer). F( samplesshowed onset of bloom (32 cycles) and complete bloom (38cycles) at 3, 6 and 9mm distance while F2 onset of bloom (36cycles) and complete bloom (41 cycles) in all distances. Thismay be attributed to the compatibility between coconut oiland PKS and chemical incompatibility between lauric fatsand cocoa butter, this result was supported by Laustsen(1991) who suggested that, bloom in lauric based compoundsis caused by migration of trilaurin to the surface of chocolaterather than, as commonly believed, due to migration of cocoabutter. The percentage of fat in the filling and the chocolatelayer attained equilibrium values after 6 weeks storage periodin the chocolate filled with F[, whereas in F2 the net fat mi-gration occurred after 4 weeks time. Since the lipid in F2 ismore liquid than F( and both are usually more liquid than co-coa butter at room temperature, they tend to migrate moreeasily into the chocolate structure. The use of desiccated co-conut in F2 increases the rate of movement by 100% in F2than Fj.The extent of triglycerides movement from a biscuitbase into its chocolate coatings depend on storage time, tem-perature, SFC and the fat content of the base (Tali bot 1990).ConclusionsThe migration of lauric fat from the filling into the darkchocolate changed the physical and chemical properties ofcocoa butter. Both fillings show improved bloom resistance(5-7 weeks). using desiccated coconut improve the bloom re-sistance by 6 cycles. Thus palm kernel stearin and desiccatedcoconut showed bloom resistance at 30°C, this combinationwould be the best filling if the chocolate stored below 25°C.ReferencesDimick, P ..S' and Manning. D.M. 1987. Thermal and compositionalproperties of cocoa butter during static crystalization. J. Am. Oil.Chern. Soc. 64(12): 1663-1669.Herzing, ~.G. 1989. Eutectic effects of fats and their application forconfectionery centers. The Manufae. Confect. 83-87.Laustse~, K. ~991. The nature of fat bloom in molded compoundcoating. Ibid. 71(5): 137.Talibot, G. 1990. Fat migration in buscuits and confectionery sy-sytem. Confee. Prod. 56(4): 225-272.Supported by IRPA Grant 01-02-04-0261167

Mechanism of fat migration of lauric hard butter (PKS) and non lauric fat (PMF) based filling centre in dark chocholate

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Mechanism of fat migration of lauric hard butter (PKS) and non lauric fat (PMF) based filling centre in dark chocholate

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