CHANGES ON THE SOLID FAT CONTENT OF PALM OIL/SUNFLOWER OIL BLENDS VIA INTERESTERIFICATION

Abstract Physicochemical characteristics of binary blends containing refined-deodorized-bleached palm oil (RBDPO) and sunflower oil (SFO) were studied before and after chemical interesterification at different temperature (110 o C (CIE1) and 80 o C (CIE2)) using sodium methoxide as catalyst. Thirty-three samples with different ratios were analyzed for triacylglycerol (TAG) composition, fatty acid composition (FAC) and solid fat content (SFC) profile. Upon CIE, extensive rearrangements of fatty acids among triacylglycerol (TAG) were seen. Generally, CIE not induced enormous changes in the TAG compositions of ratio 8:2 and 5:5 of RBDPO:SFO blends. However, CIE induced enormous changes in the TAG compositions of the 9:1, 7:3, 6:4, 4:6, 3:7, 2:8 and 1:9 blends, which some of the TAGs were increasing while the other decreasing. These changes in TAG profiles resulted in some changes in the physical properties (especially SFC) of the blends. Generally, the SFC of interesterified blend were decreased after CIE1 and increased after CIE2, except for sample 10:0, 8:2, 7:3, 5:5 and 9:1 which were decreased after CIE1 and CIE2. As a conclusion, CIE1 and CIE2 successfully changed the physicochemical characteristics of the binary blends. Keywords: palm oil, sunflower oil, interesterification, blending, solid fat content Abstrak Ciri-ciri fiziko-kimia adunan duaan langsung minyak sawit tertapis, terluntur dan ternyahbau/minyak bunga matahari (RBDPO/SFO) dikaji sebelum dan selepas penginteresteran kimia pada suhu berbeza (110 o C (CIE1) dan 80 o C (CIE2)) dengan menggunakan mangkin natrium metoksida. Sebanyak 33 adunan dengan nisbah yang berbeza dianalisis menggunakan kaedah penentuan komposisi triasilgliserol (TAG), komposisi asid lemak (FAC) dan kandungan lemak pepejal (SFC) yang dilakukan sebelum dan selepas penginteresteran kimia. Penyusunan semula asid-asid lemak pada molekul-molekul TAG dikesan selepas penginteresteran kimia. Umumnya, penginteresteran kimia merangsang perubahan yang tidak begitu ketara di dalam komposisi TAG adunan 8:2 dan 5:5. Walaubagaimanapun, penginteresteran kimia telah merangsang perubahan yang agak besar bagi adunan 9:1, 7:3, 6:4, 4:6, 3:7, 2:8 dan 1:9 dengan beberapa jenis TAG meningkat, manakala yang lainnya menurun. Perubahan di dalam profil TAG menyebabkan perubahan ke atas sifat-sifat fizikal terutamanya kandungan lemak pepejal adunan duaan minyak. Kandungan lemak pepejal bagi adunan-adunan yang terinterester menurun selepas CIE1 dan meningkat selepas CIE2, kecuali bagi adunan 10:0, 8:2, 7:3, 5:5 dan 9:1 yang menurun selepas CIE1 dan CIE2. Keseluruhannya, CIE1 dan CIE2 berjaya mengubah ciri-ciri fiziko-kimia adunan minyak. Kata kunci: minyak sawit, minyak bunga matahari, adunan, kandungan lemak pepejal Introduction Most native vegetable oils have specific characteristic in their original forms due to their specific chemical composition that reflect specific physical properties and nutritional value, which limit their applications. To enlarge the usage of these oils, they have been modified either chemically (interesterfication or hydrogenation) or physically (fractionation