Antioxidant activity compared ORAC

Much less is known on the antioxidant activity of tocotrienols than tocopherols. Tocotrienols were shown to have similar reactivities to peroxyl radicals and antioxidant activities than tocopherols in solution and membranes (Yoshida et ah, 2003) also, in general, y-tocotrienol was a better antioxidant than a-tocotrienol, and tocotrienols were better than tocopherols in oil systems (Seppanen et ah, 2010). Recently, Muller et ah (2010) conducted a comparative study to investigate the four tocopherols, four tocotrienols, and a-tocopheryl acetate on their antioxidant activities in five different popular in vitro assays (FRAP, a-TEAC, DPPH, ORAC, and CL), which were adapted to nonpolar antioxidants. Most notably, they found that a-tocopheryl acetate, a popular ingredient in supplements, had no significant antioxidant activity in vitro. However, once ingested, tocol esters are hydrolyzed and antioxidant activities are retained. Overall, the eight tocols performed similarly in the five assays. The authors concluded that in vitro antioxidant assays performed in polar solvents are not a good way to predict in vivo antioxidant activity. 

A comparison of antioxidant activities reported in literature, for a number of regularly consumed fiuits and vegetables, and those obtained by using the TEAC, ORAC, and FRAP assays is presented in Tables 1, 2, and 3, respectively. A 2002 study utilized these assays to assess comparatively the antioxidant... 

---