绿色高效连续分离技术制备蛋黄中活性蛋白质和磷脂

Active Proteins and Phospholipids Prepared from Chicken Egg Yolk by Green and Efficient Sequential Separation Technology

为了实现蛋黄功能性成分的充分利用,采用绿色溶剂从新鲜蛋黄中高效连续分离具有生物活性的卵黄免疫球蛋白(immunoglobulin Y, IgY)、卵黄高磷蛋白(phosvitin, PV)和磷脂(phospholipids, PL)。首先采用水稀释法(稀释倍数为1:10)分离水溶性组分与脂蛋白,通过35%饱和(NH4)2SO4和0.5%NaCl(w/v)对上清液进行盐析并用8%PEG 6000纯化IgY。脂质组分中的PV在pH5.0,90℃条件下的NaCl溶液(w/v)中进一步纯化。采用乙醇/乙酸乙酯比例为1:2(v/v)提取蛋黄中全部脂类,进一步采用乙酸乙酯在0℃下提纯蛋黄总脂中的PL。经脱盐、冷冻干燥后,IgY、PV和PL的纯度分别为97.38%、78.63%和85.94%。IgY和PV的得率分别为6.15、10.15 mg/mL。蛋黄总脂中PL的含量为35.18%。因其良好的多不饱和脂肪酸/饱和脂肪酸比率(0.70)和相对较低的n-6/n-3比率(5.37),该PL产品可应用于食品加工中。本方法简便、环保并且高效,可从蛋黄中依次分离出高纯度IgY、PV和PL,并为蛋黄的综合利用提供技术支持。

In order to achieve the full utilization of the functional components of egg yolk, a green solvent was used to separate bioactive immunoglobulin Y(IgY), phosvitin(PV), and phospholipids(PL) from fresh chicken egg yolk efficiently and continuously. Firstly, the water-soluble fraction was separated from the lipoproteins by water dilution(dilution ratio of1:10), and the supernatant was salted by 35% saturated(NH4)2SO4 and 0.5% NaCl(w/v) and IgY purified by 8% PEG 6000.The PV in the lipid fraction was further purified in NaCl solution(w/v) at pH5.0, 90 ℃. All lipids in egg yolk were extracted using an ethanol/ethyl acetate ratio of 1:2(v/v), and PL in total egg yolk lipid was further purified using ethyl acetate at 0℃. After desalting and freeze-drying, the purity of IgY, PV and PL was 97.38%, 78.63% and 85.94%, respectively. The yield of IgY and PV was 6.15 mg/mL egg yolk and 10.15 mg/mL egg yolk, respectively, and the content of PL in lipids accounted for 35.18%. The PL product may be served as a good source of dietetic applications due to its favorable PUFA/SFA ratio(0.70) and comparable lower n-6/n-3 ratio(5.37). These results proved that IgY, PV and PL can be purified in sequence from egg yolk with high purity. Also, this method is very simple, environment friendly and can provide technical support for the comprehensive utilization of egg yolk.