Cooking oils can be mixed and matched with different cooking methods. For example, olive oil is high in monounsaturated fatty acids, and extra virgin olive oil contains many nutrients, giving it a unique aroma, making it suitable for cold dishes. Some consumers prefer to use olive oil for cooking because it is rich in unsaturated fatty acids. Xu Chunxiang states that all cooking oils contain various types of fatty acids, but their content varies. Typically, through identification tests, one can determine the type of oil by analyzing the composition of fatty acids. "Oils high in unsaturated fatty acids are not suitable for frying," he explains. Although they do not easily form cholesterol, unsaturated fatty acids are unstable and can break down when heated, oxidizing and polymerizing during frying, potentially producing harmful substances. In contrast, palm oil, commonly used in instant noodles, has a high saturated fatty acid content and remains stable when heated, making it suitable for frying. When using oils high in unsaturated fatty acids for stir-frying, it is particularly important to avoid prolonged heating.