Degradasi Kalsium Oksalat Pada Tepung Porang Menggunakan Kavitasi Microbubble

Abstract

Porang flour contains a fairly high calcium oxalate (CO) in which consuming it directly can cause kidney stone disease in humans. The aim of this study was to obtain the optimal operating parameters of the CO degradation process in porang flour using a swirling-flow nozzle hydrodynamic cavitation technique. This study consists of 3 stages; stage 1 determining the particle size, concentration of NaCl solution and ratio (porang flour: NaCl solution: isopropyl alcohol) to the level of viscosity for the cavitation process; the 2 nd stage, determining the limit values on the air flow rate, fluid, and cavitation time to optimize the CO degradation; 3 rd stage, CO degradation process with variable operation on hydrodynamic cavitation technique by swirling-flow nozzle type. The hydrodynamic cavitation tool used in this study had a 7 mm nozzle orifice in a vertical position. The nozzle used is made of Plexiglas with an outer diameter of 80 mm and a height of 160 mm which consists of a vortex chamber and air holes. The fluid flow in this tool is regulated by a centrifugal pump type. The optimization process was carried out using the response surface method of the box-behnken model in design expert 13.0 software with 17 formulations and 3 verification processes for optimal operating parameters. The finest solution formulation could pass through the nozzle and formed microbubbles with a viscosity level of >10 cP on 40 mesh particles, 5% NaCl concentration, and ratio (porang flour: NaCl: isopropyl alcohol) 1:20:20 (w/v). The limit values for the optimization process were in the range Qg = 0.5-1.5 lpm, Ql = 8-12 lpm, and cavitation time of 15-25 minutes. The preeminent CO degradation process was obtained at Ql/Qg = 10/1 lpm ratio with a cavitation time of 20 minutes. This process produced 29.7 mg/100g CO content with a degradation percentage of 85.53%. The produced calcium oxalate indicates that it meets the required standard tolerance limit for the human body which is 71 mg/100g, and below SNI 7938:2020 which is a maximum of 30 mg/100g. In other words, porang flour produced from this process is safe for consumption.