Effect of pH, Enzymes and Bacteria Culture on Virgin Coconut Oil Yield from Coconut Milk

Abstract

Virgin Coconut Oil (VCO) has excellent investment potential and is becoming more and more popular among the community. The present investigation deals with 18 treatments for coconut milk to find out the combination effect of extraction process for maximum yield of virgin coconut oil (VCO) from coconut milk extracted from coconut meat. Optimization of the process parameters including pH (4 and 6), cellulase enzyme concentration (0.1%, 0.2%) and Lactobacillus bacteria culture (5%, 10%) was analysed using factorial method. Optimum treatments were selected and quality characteristics of VCO were compared with the SLS, APCC and CODEX standards. Best conditions were determined in treatment 11 (pH 6, enzyme 0.1% w/v, bacteria culture 0%) and treatment 12 (pH 6, enzyme 0.2% w/v, bacteria culture 0%), both produced a higher yield of VCO (17.34%, 16.25%). There was no significant effect among the above mentioned three factors (p > 0.05). The results indicated that; pH being the most significant factor while enzyme concentration was the second most important factor that significantly influences VCO yield. Isolated bacteria culture (Lactobacillus strain) has no effect (p > 0.05) on the VCO yield. According to the ANOVA test, there was no significant difference of FFA%, Lovibond color value, and refractive index and delta k values among VCO obtained from 18 treatments while moisture content is having an effect (p < 0.05) on the interaction of pH and bacteria culture. Quality parameters of VCO from treatment 11 and 12 such as moisture content (0.27% and 0.23%), FFA% (0.2%, 0.25%), refractive index (1.447, 1.447), Lovibond color value (0.9, 0.3), delta k value (-0.116, -0.116), phenol content (1.632,0.98 mg GAE/g oil), radical scavenging activity (35.95%, 29.4%) and fatty acid profile (Lauric acid%) (50.004%, 50.155%) are within the SLS standards at the same time compatible with previous research findings.