Phospholipase A₂ (PA₂) is an enzyme derived from porcine pancreas. It serves as a catalyst in the hydrolysis of the fatty acid in the second position of phospholipids/lecithin.

phosphatidylcholine 1-acylglycerophosphocholine + fatty acid

This process results in the conversion of approximately 70% of the lecithin found in egg yolk to lysolecithin, which has much better emulsifying properties than lecithin.

APPLICATION
PA₂ can be used in the production of heat-stable egg yolk. Enzyme modified egg yolk offers a number of benefits in various food systems, including mayonnaise, sauces, dressings, baking and ice cream.

One benefit provided by enzyme-modified egg yolk is better emulsifying properties than untreated egg yolk; this functionality serves to stabilize otherwise incompatible ingredients. Modified egg yolk also demonstrates a high degree of stability at elevated temperatures (i.e. 70°- 80°C) compared to untreated yolk that has little tolerance for temperatures above 60°C.

Modified egg yolk treated with PA₂ has demonstrated superior stability at retort temperatures above 150°C when used in certain food systems (i.e., mayonnaise). This stability allows for the incorporation of pasteurization into processing, which is critical for microbial quality and which also contributes to increased shelf life.

Increased viscosity is another benefit offered by modified egg yolk, which is particularly important in the production of mayonnaise.