wikipedia上说厨师们是用Walnut Oil凉拌,而避免用walnut oil进行高温烹饪. Although chefs sometimes use walnut oil for pan frying, most avoid walnut oil for high temperature cooking; heating tends to reduce the oil's flavour & nutritive value and to produce a slight bitterness. In addition cooking rapidly destroys the oil's antioxidants. Walnut oil is at its most valuable in cold dishes such as salad dressings, where it lends its flavour to best advantage. http://en.wikipedia.org/wiki/Walnut_oil