Oil Oxidation Control, Naturally

One of the challenges with many specialty oils is preventing oxidation―especially in those that contain a high level of unsaturates. These double bonds are extremely susceptible to oxidation. Add light and exposure to air, plus mix with any number of pro-oxidants, like salt, and you have a recipe for rancidity.

To extend oil shelf life, suppliers routinely add antioxidants to susceptible oils, but consumers are increasingly shying away from synthetic additives like BHA and BHT, especially in premium products. Some oils are naturally high in antioxidants, such as vitamin E, but many require an added boost to increase performance under practical conditions. “Typically, a blend of natural ingredients, including natural herb extracts and various vitamins, can result in a perfect solution for your oil application,” says John C. Weaver, Ph.D., product application and development director, Kalsec, Inc., Kalamazoo, MI.

“In addition to tocopherols acting as a free-radical scavenger, citric acid may be added to a natural extract blend to inhibit the initiation of oxidation―a preventative antioxidant―by chelating metals present in the oil system,” says Weaver. “Also, ascorbic acid―vitamin C―will help regenerate antioxidants like tocopherols and natural phenolic antioxidants by acting as a reducing agent within oil systems.”

Extracts of rosemary and sage are among the most-common natural, spice-based oxidation inhibitors. Rosemary, for example, has a variety of compounds responsible for antioxidant activity, most notably the phenolic diterpenes carnosic acid and carnosol, explains Weaver.

Low-flavor products are available, so they impart little to no flavor in oils when used at effective levels. “Usage levels can vary between 0.1% and 0.4%, depending on the product being used, the oil being stabilized and the application,” says Weaver. “This can give a specialty-oil based product a clean label since the product is simply labeled ‘natural flavors.’”

For more information, see Pouring On Specialty Oil Ideas