This test method is a procedure used to determine the amount of acetone-insoluble matter in vegetable lecithins. This test measures the percentage of material in lecithin that does not dissolve in acetone, primarily consisting of phospholipids, glycolipids, and other high molecular weight, non-oil components. In this method, a weighed sample of lecithin is mixed with acetone under controlled conditions. The insoluble matter is separated by centrifugation, dried, and weighed. The result is expressed as a percentage of the original sample.