Optimasi Pencampuran dalam Proses Produksi Susu Kental Manis Lemak Nabati Rekombinasi (Studi Kasus di PT. XYZ)

Abstract

Ones of the critical stages in the manufacture of sweetened condensed milk recombination is mixing. This is caused by the characteristics of skim milk powder (SMP) used as the main raw material is quite difficult as well as total dissolved solids mixing reached 69%. Criteria for optimal mixing results shown by the solubility index, where the lower the index value of the solubility of the better quality mixing results. Based on data owned by PT. XYZ, the optimum mixing process is <0.1 ml. Capacity of mixing in PT. XYZ in 2009 is 7 tons for 70 minutes, by market demand and efficiency of the capacity was increased to 9 ton/60 minutes while maintaining the solubility index values <0.1 ml. So that the necessary optimization of critical parameters such as agitator speed, the use of high shear mixer and dosing speed of powdered milk. This study aims to determine the critical parameters of the mixing process to obtain appropriate quality standards with the most optimal processing time Methods the study consisted of three phases, namely design review process mixing equipment between the previous (7000 kg/70 min) with the new 9000 kg/60 minutes. The second research phase is to determine the speed of inline high shear mixer pump by performing experiments at 2000 rpm, 2500 rpm and 3000 rpm. Phase 3 study is the optimization of the mixing process by using a completely randomized experimental design, namely: Powder Inlet velocity (120, 150 and 180 kg/min); hydration time (5,10 and 15 minutes). So of all the combinations obtained nine different treatments. Analytical methods used to measure the quality of mixing is a method used in PT. XYZ are: solubility index, total solids, fat content, viscosity, specific gravity and pH. Then to see the influence and interaction of each treatment tested a real difference and linear regression to obtain the optimal parameters according to design. From the experimental results can be seen that the speed of inline high shear mixer pump is best at 2500 rpm.. The best results of mixing time is 65 minutes and solubility index <0.1 ml at the treatment A2B1 (milk powder dosing rate 155 kg/min and hydration time for 5 minutes). The relationship between the hydration time and milk powder dosing rate to solubility index is expressed in the equation Y = 0.192 + 0.001 A-0,013B, where: A = milk powder dosing rate, B = hydration time, Y = solubility index. While the relationship between the hydration time, milk powder dosing rate with respect to mixing time is expressed in the equation Y = 26.556 + 0.3 A +0.6 B, where: A = milk powder dosing rate, B = hydration time, Y = total mixing time.