ULTRASOUND ASSISTED ENZYMATIC DEGUMMING: CHANGES IN PHYSICOCHEMICAL AND NUTRACEUTICAL PROPERTIES

Crude soybean oil contains phosphorus which influences oxidation and contributes towards formation of colloidal aggregates, therefore it must be removed. Enzymatic degumming (EDG) and ultrasound assisted enzymatic degumming (UAEDG) are fairly recent techniques and has been showing great efficiency on the removal of phosphorus content. The present study compares the effect of various degumming processes: water, chemical, enzymatic and ultrasound assisted enzymatic degumming upon residual phosphorus content, fatty acid profile, and total carotenoids. Samples of crude soybean oil of 300 g were subjected to degumming processes. The water degumming (WDG) was performed with a 3% water addition, a reaction temperature of 85 °C during 15 min. For the chemical condition (CC), a 30% aqueous solution of citric acid and an aqueous solution of sodium hydroxide (14%) were added to the oil, during 15 min. The EDG trials were performed by using 200 mg/kg of PLC-3G, 60 °C, 3% of water, pH 5.6, during 120 min. UAEDG trials were performed at the same conditions of EDG, with the addition of an ultrasound power of 154W, in order to compare the processes. The phosphorus content of EDG was reduced below 40 mg/kg after 2 hours of incubation, while UAEDG could produce degummed oil with 22 mg/kg of phosphorus in 1h. The phosphorus concentration could not be reduced to an acceptable level using water or citric acid degumming, reaching 92 mg/kg and 123 mg/kg, respectively. The fatty acid profile of the processed oil indicated no significant change. The total carotenoids content presented higher reductions in the UAEDG trials. However, the reduction in total carotenoids was not higher than 10% at all trials. Therefore, application of UAEDG effectively increases the reaction rate in a short time. Thus, emphasizing that ultrasound can be effectively applied to enzymatic degumming of crude soybean oil.