Aromatic peanut (groundnut) oil (APO) is produced from roasted peanuts, and hence has stronger peanut aroma than refined peanut oil. It is popular in Chinese, Indian and SE Asian cuisine. Chinese researchers determined the tocopherol content of APO and 4 refined vegetable oils (soybean, sunflower, maize, and rapeseed oils) using hplc with UV detection. The tocopherol isomer content, especially α and γ tocopherols, were found to be the most suitable markers to disciminate between APO and the 4 vegetable oils. In addition, APO was mixed with the 4 oils (at the levels of 5, 10, 15, 20 and 25 g/100 g, w/w) to determine whether the tocopherol analysis is a better approach than fatty acid profiling for detecting APO adulteration. The results showed that for tocopherols, the detection limits were 5 g/100 g for soybean oil and 10 g/100 g for other three oils in APO, showing a higher sensitivity than fatty acids profile based method for detecting APO adulteration.
Read the abstract here