Oil Smoke Point Testing of Camellia oleifera

Camellia oleifera seed extract, or tea-seed oil, has been used in China and southeast Asia for thousands of years as a cooking oil. It is commonly referred to as “eastern olive oil” due to health benefits associated with its consumption. Camellia oleifera has been found to thrive as an oilseed crop in the state of Georgia. One of many claimed characteristics of Camellia oil is it's relatively high smoke point, around 250^oC, which is higher than olive oil. The smoke point has been defined as the minimum temperature at which a constant stream of smoke is emitted from a heated oil or fat. There is an abundance of claims on the smoke point temperatures of various cooking oils, however, little work has been conducted by research institutions on these smoke points and little to no research on tea-seed oil specifically. Determining the smoke point is important because when cooking oil reaches this temperature it degrades and starts to release free radicals. Oxygen derived free radicals are thought to be related to the formation of cancer, inflammation, atherosclerosis, ischemia-reperfusion injuries, aging, Alzheimer’s disease, shock, diabetes, cataracts, hypertension, cardiovascular disease, exercise related muscle damage and infertility. Seventeen oils were tested in accordance to AOCS method Cc 9a-48, or the Cleveland open cup method. Fourteen of the oils were commercial cooking oils, three being Camellia. Of the tea-seed oils, two were unrefined samples from Georgia grown bulk seed and the third sample was commercially refined. Testing found peanut and safflower oils to have the highest smoke point. Crude and centrifuged tea-seed oil had the lowest smoke points, however commercially refined tea-seed oil had a higher smoke point temperature than extra virgin olive oil by 28^oC indicating greater stability under high heat stress. Preliminary fatty acid profiling has also been conducted on bulk seed from locally adapted cultivars and the percent oleic acid compares favorably with tea-seed oil from China. Comparable fatty acid profiles suggest that Georgia grown Camellia may exhibit the same health benefits as its Asian counterpart. Further research will be conducted to determine the frying performance of Camellia oil and its characteristics when converted to biodiesel.