**3.2 Preparation of powdery soybean phospholipids**

The applications of concentrated phospholipids are limited due to its high content of neutral oil, fatty acids and other substances and its low purity and off-flavor formation. Refining and purifying processings are needed to consistent the phospholipids products with the high purity and non off-flavor specifications of functional food material.

Methods of producing high purity phospholipids from concentrated phospholipids include solvent extraction, ultrafiltration purification, supercritical carbon dioxide extraction etc. So far, acetone solvent extraction is the most widely used method in industry.
