I have read that one should be certain of the quality of lecithin granules before purchasing. How can that be done?

You want to make sure the lecithin granules are produced from pure, whole, non-GMO soybeans. Some companies use soy flour, which is not a good source of lecithin. Make sure it does not contain any additives or fillers…no sugar, salt, starch, yeast, wheat, gluten, corn, milk, egg, colorings, flavorings or preservatives. Enjoy!