how would you test for the presence of a lipid in a sample of food
Emulsion test Add ethanol to the solution you want to test, and add water. A colour change to cloudy white shows that lipids are present.
Food spoilage Signs of food spoilage may include an appearance different from the food in its fresh form, such as a change in color, a change in texture, an unpleasant odor, or an undesirable taste. The item may become softer than normal. If mold occurs, it is often visible externally on the item.