Photolysis of alpha-tocopherol in olive oils and model systems
PIRISI, FILIPPO MARIA;ANGIONI, ALBERTO;
1998-01-01
Abstract
The photolysis of a-tocopherol (I) in olive oil (O) acid in some model systems (n-hexane = H; anhydrous n-hexane = KA, and triolein = T) was studied under sunlight and under artificial light (lambda > 290 nm) by HPLC and GC/MS. In O and T, I disappeared linearly to 50% of the starting concentration, reached a constant value, and finally disappeared rapidly from the medium. In the model system, photolysis followed a pseudo-first-order kinetics. Although no peaks attributable to photoproducts were found in O, a main product identified by H-1 and C-13 NMR and GC/MS as 5-formyltocopherol (II) was found in the model systems. Irradiation of compound II led to species undetectable by HPLC in agreement with a slower consecutive kinetic process than that of I. In the HA and T systems, the formation of II occurred at lower levels than in H. The possible behavior of photodegradation is discussed.Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.