Sterile eggs can eliminate the possibility of being infected by salmonella. The more egg yolk is contained in the custard sauce, the less starch is needed for a stable cream sauce. For example, every increase of100g of egg yolk can reduce the consumption of10g of corn starch or rice starch. The reason why egg yolk makes cream sauce delicious is the presence of lecithin (8%), which also makes cream sauce more suitable for freezing and prevents separation.