During commercial food processing, fats sometimes undergo the process of hydrogenation, where the structure of the fat becomes “hardened.” Almost all margarines and all products, that list fats or oils in their ingredient list contain hydrogenated fats.
Hydrogenation is the most common way of drastically changing natural
are eaten by people. The presence of aluminum is particularly worrisome, because
The problem is that many oils begin to oxidize and therefore turn into trans-fats even before they are put into the commercial fryer to make French fries. Refined vegetable oils, sold in clear bottles, react with light and begin to turn rancid already on the shelf of your supermarket. Using butter, coconut oil and pure extra virgin organic olive oil and sesame oil, sold in dark bottles will help you to limit your trans-fat intake. Avoiding all processed foods will help you even more. The following is a table of smoke point of different oils.Once a fat starts to smoke, it usually will emit a harsh smell and fill the air with smoke. Fats that have gone past their smoke points contain a large quantity of free radicals and become carcinogenic, so it's a good idea to cook with oils, which have a high smoke point.
Fat Smoke Point °F Smoke Point °C Unrefined canola oil 225°F 107°C Unrefined flaxseed oil 225°F 107°C Unrefined safflower oil 225°F 107°C Unrefined sunflower oil 225°F 107°C Unrefined corn oil 320°F 160°C Unrefined high-oleic sunflower oil 320°F 160°C Extra virgin olive oil 320°F 160°C Unrefined peanut oil 320°F 160°C Semirefined safflower oil 320°F 160°C Unrefined soy oil 320°F 160°C Unrefined walnut oil 320°F 160°C Hemp seed oil 330°F 165°C Butter 350°F 177°C Semirefined canola oil 350°F 177°C Coconut oil 350°F 177°C Unrefined sesame oil 350°F 177°C Semirefined soy oil 350°F 177°C Vegetable shortening 360°F 182°C Lard 370°F 182°C Macadamia nut oil 390°F 199°C Refined canola oil 400°F 204°C Semirefined walnut oil 400°F 204°C High quality (low acidity) extra virgin olive oil 405°F 207°C Sesame oil 410°F 210°C Cottonseed oil 420°F 216°C Grapeseed oil 420°F 216°C Virgin olive oil 420°F 216°C Almond oil 420°F 216°C Hazelnut oil 430°F 221°C Peanut oil 440°F 227°C Sunflower oil 440°F 227°C Refined corn oil 450°F 232°C