Production of red palm oil and red palm fats by vacuum frying sterilization and multi-step fractionation

The question on health impact of the refining palm oil has driven the oil palm producers in Thailand toward developing the wellness products that are in high demand in the future. Red palm oil (RPO) which is rich in carotenoids and vitamin E catches attention. However, production of RPO by the current steam sterilization method has negative impact on environment and requires high capital investment, while the cost-saving dry sterilization method delivers a low-quality product. To develop the effective RPO processing method suitable for the small and medium-size enterprises (SMEs), the vacuum frying method was studied. The whole production steps consist of vacuum frying sterilization, acid degumming, neutralization, and then multi-step fractionation. The steam sterilization method was compared by using the same arrangement step except the sterilizing procedure. Sterilization by the vacuum fryer was controlled at 80 °C, -400 to -720 mmHg. Results showed that the optimal vacuum frying time was 90 min. The fractionation temperatures of the vacuum frying method were 34 °C, 27 °C and 17 °C, whereas those of the steam sterilized method were 34 °C, 25 °C and 15 °C. Quality of RPOs produced from both methods were within the edible oil standard. The vacuum frying method produced the RPO with 0.17% free fatty acids, 6.65 meq.O2/kg peroxide value, 620 mg/kg carotenoids, 835 mg/kg vitamin E and 61.31% yield. The main advantage in term of quality of the vacuum frying method lies mainly in improving yield and oil odor, which is a sensory characteristic that play an important role in consumer acceptance of the product. The red palm fats obtained from the multi-step fractionation provided a wide range of fats suitable for different applications. Therefore, the vacuum frying could be regarded as the sustainable process technology appropriated for the SMEs.