Peanut oil and vegetable oil are often used interchangeably for cooking.
The only notable advantage peanut oil has over vegetable oil is a higher smoke point. Peanut oil can get very hot before smoking or burning, therefore it is often included in recipes for deep-frying foods. Other than that, there is really no reason vegetable oil cannot be used instead of peanut oil.
Similarities and Differences
Vegetable oil is extracted from a variety of different nut and vegetable sources mixed together. It is usually a light golden color with an almost indistinguishable flavor. Many vegetable oils contain primarily polyunsaturated and monounsaturated fats. These fats may be more heart-healthy than saturated fats. Among the vegetable oils containing polyunsaturated fats are safflower, corn, sunflower and soy. Vegetable oil is a good source of vitamin E and essential fatty acids. It is also a good source of phyto-sterols, which inhibit cholesterol absorption across the gut and can reduce cholesterol levels. All oils are also high in calories. There are 120 calories per tablespoon of vegetable oil. It is 100 percent fat with no carbs and no protein.
Peanut oil is made exclusively from peanuts. A strong, dark peanut oil has a distinct flavor and is often used in Asian cooking for its flavor and ability to maintain high temperature in a wok. Peanut oil is high in energy; one tablespoon has 120 calories. It is one of the cooking oils with a high smoke point at 450 degrees Fahrenheit. Peanut oil has a very good lipid profile with saturated, monounsaturated and polyunsaturated fats in healthy proportions.
Choosing an Oil
Cooking oils are recommended based on use. Both vegetable oil and peanut oil will emit a smell the hotter they become. They will each turn dark and become inedible at their "smoke point." Peanut oil has a higher smoke point than vegetable oil, so it is generally used for deep-frying and other cooking needs involving higher temperatures. With some modifications, peanut oil can be replaced by other oils. Vegetable can be used in place of peanut oil for any type of sautéing or pan frying.
Peanut oil in any recipe can affect individuals with peanut allergies and should therefore be avoided. It’s unlikely that highly refined peanut oil contains the protein elements that trigger a peanut allergy reaction, but why take the chance when vegetable oil is an adequate substitute?
Sources: Nutrition and You, eHow