Optimization of virgin coconut oil production with pulse electric field pretreatment (A study on voltage and frequency)

Abstract

VCO is made by protein demulsification. One way to break down the emulsion is by centrifugation. PEF is a non-thermal method that can break down cell membranes. In this study, the pretreatment process of Pulsed Electric Field (PEF) aided the coconut milk extraction process. The purpose of this study was to determine the optimal voltage and frequency of PEF at pretreatment of coconut milk extraction in the manufacture of VCO. The design of the study is the Response Surface Method (RSM) with the Central Composite Design using 2 factors namely voltage and frequency. In accordance with RSM method, two factors were repeated at the midpoint (X=0) 5 times at a voltage of 3 KV/cm (X1 = 0) and a frequency of 2.25KHz (X2 = 0). The value of α chosen was k=2 at 2k/4 = 22/4 = 1.414. Optimal results were obtained from the treatment voltage of 3.277 KV/cm and a frequency of 2.560 KHz. This condition resulted in yield of 17.57%, density of 0.918%, the moisture of 0.258%, and free fatty acid content of 0.357%. Prediction results were very good because the deviation was less than 5%, except for free fatty acid levels.