Supercritical Carbon Dioxide Extraction of Malaysian Stingless Bees Propolis: Influence of Extraction Time, Co-modifier and Kinetic Modelling

Abstract

In the present work, the influence of extraction time and co-modifier on the yield of two types of MSB propolis, hard and sticky, using supercritical carbon dioxide extraction technique were evaluated. Different pressure, CO2 flowrate and co-modifier percentage was studied at constant 40°C. SCCO2 extraction was carried out at high (25MPa, 5 ml min−1 CO2, 7% ethanol) and low (15MPa, 3 ml min−1 CO2, 3% ethanol) operating conditions for both hard and sticky MSB propolis. The result shows that 240 minutes was the best and efficient extraction time. Meanwhile, at high operating condition in SCCO2 technique has increased extraction yield of 1.1608g and 0.5656g for both hard and sticky MSB propolis with the addition of co-modifier. Extraction yield without co-modifier addition was 0.3602g and 0.0542g for hard and sticky MSB propolis, respectively. Co-modifier addition to the process had increase the extraction yield as much as 10 folds higher for sticky MSB propolis whilst, 3 folds higher for hard MSB propolis. These findings show that SCCO2 method propose a feasible technique for MSB propolis extraction as it only require short extraction time and complemented with co-modifier application. Brunner and Esquivel model were used to determine the kinetic behaviours in the extraction process. The maximum extraction rate found was 3×10−4 g sec−1 from the fitting the kinetic models.