Ultrasonic-assisted Extraction of Lecithin from Egg Yolk and Its Physicochemical Properties

Purpose:To investigate an ultrasound-assisted extraction process for lecithin from egg yolk as well as the properties, including antioxidative ability and storage stability of the lecithin. An ultrasound-assisted extraction process for lecithin from egg yolk and that the property of the lecithin was studied. Methods:Response surface methodology (RSM) was employed to optimize the main parameters (including ratio of liquid to solid, ethanol concentration and extraction time). TLC and FT-IR were employed to determine the structure of lecithin. GC-MS was used to analyze the fatty acids composition of lecithin. The stability and antioxidation properties of lecithin were examined. Results:The parameters of ultrasound-assisted ethanol extraction of lecithin from egg yolk were optimized, and the results were as follows:the ratio of liquid:soild 15:1 (mL/g), ethanol concentration 92%, and extraction time 22 min. Under these optimal conditions, 375.69 mg/g of lecithin were obtained. Through TLC and FT-IR, the extracts were confirmed to be lecithin. Gas chromatography-mass spectrometry (GC-MS) was employed to determine the fatty acids compositions of in the as-obtained lecithin. It showed that the major unsaturated fatty acids were oleic acid and linoleic acid;saturated fatty acids were palmitic acid and stearic acid. Light and temperature affect the antioxidation and stability of lecithin and lecithin from egg yolk showed better stable and antioxidative capabilities than that from soybean. Conclusions:Ultrasound-assisted ethanol extraction was a suitable procedure for lecithin from egg yolk. The findings are helpful to provide basic information on extraction, storage and utilization of lecithin from egg yolk in future.