Corn, safflower, sunflower, flax (linseed), walnut, hazelnut, hemp, pine nut, pumpkin, and wheat germ oils should only be used raw and in small amounts. Never cook with these nut and seed oils as they are polyusaturated dominant. They are delicate and easily damaged by heat, light, oxygen, and moisture, so refrigeration in a tightly sealed, opaque bottle is a must. Look for cold-pressed, unrefined versions only.
玉米油、红花籽油、葵花籽油、核桃油、榛子油、亚麻油、松子油、南瓜子油以及麦胚油只能生食，而且用量要小。绝对不要烹饪这些果实及其油脂，原因是它们是富多不饱和脂肪酸的油脂。它们比较脆弱，遇热、遇光、遇氧、遇潮都会变质，因此要密封于不透明的容器并置放于冷藏箱中。在选购的时候要选择冷轧的而不要精炼的。
[杜编：我个人的经验是葵花籽油的确容易变质，但是葡萄籽油似乎非常稳定，虽然它也属于多不饱和脂肪酸主导的油脂。刚来美国的时候我也常常用玉米油炒菜，没觉得有什么不好。]
