To investigate the antioxidant activity of lecithin by optimizing the process of ultrasonic-assisted ethanol extraction of lecithin from defatted egg yolk powder.
This study optimized the ultrasound-assisted ethanol extraction process using response surface methodology, investigating the effects of 3 factors: Ultrasonic time, ethanol concentration and solid-to-liquid ratio on the extraction efficiency of egg yolk lecithin. The resulting product was further purified via zinc chloride precipitation and acetone purification. The fatty acid composition, structure and antioxidant activity of the purified egg yolk lecithin were characterized.
The optimal extraction conditions were as follows: Ultrasonic time of 33 min, ethanol concentration of 94% and solid-to-liquid ratio of 1:22 (g:mL). Under these conditions, the lecithin content was 354.179 mg/g. Egg yolk lecithin was composed of 12 kinds of fatty acids, among which saturated fatty acids accounted for 53.32% of the total, and unsaturated fatty acids account for 46.68%. The infrared spectrum of egg yolk lecithin (in the wavelength of 4000–400 cm–1) was basically consistent with that of standard. The same characteristic group stretching vibrations appeared at wave numbers of 1089.5, 1220 and 2851 cm–1. High performance liquid chromatography analysis showed that the content of phosphatidylcholine (PC), phosphatidylinositol (PI) and phosphatidylethanolamine (PE) in the egg yolk lecithin sample were 268.9, 23.6 and 100.3 mg/g, respectively. The proportion of PC was approximately 89.65%, indicating that the prepared egg yolk lecithin had high purity. Lecithin exhibited good scavenging rates against 1,1-diphenyl-2-picryl-hydrazyl radical and superoxide anion free radicals, which were positively correlated with the sample concentration. The maximum scavenging rates were 52.02% and 82.2%, respectively, and the total antioxidant capacity was 80.81%.
The ultrasonic-assisted ethanol extraction method can extract egg yolk lecithin with high purity and good antioxidant activity from defatted egg yolk powder, which improves the utilization rate of defatted egg yolk powder.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |