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Role of minor constituents in the photooxidation of virgin olive oil
Author(s) -
Rahmani M.,
Csallany A. Saari
Publication year - 1998
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-998-0234-1
Subject(s) - pheophytin , chemistry , photochemistry , singlet oxygen , tbars , peroxide , quenching (fluorescence) , fluorescence , antioxidant , thiobarbituric acid , oxygen , organic chemistry , photosynthesis , biochemistry , photosystem ii , lipid peroxidation , physics , quantum mechanics
Virgin olive oil was photooxidized at 2 and 40°C and at fluorescent light intensities of 0, 620, 2710, and 5340 lux. As expected, higher fluorescent light intensities induced higher peroxide formation in the oil. The thiobarbituric acid reactive substances (TBARS) were found to be good indicators of photooxidation during the early stage of the reaction. Pheophytin A and β‐carotene were light‐ and temperature‐sensitive, whereas α‐tocopherol and total polyphenols were mostly affected by light. Pheophytin A functioned as a photosensitizer, resulting in rapid oxidation of the oil. β‐Carotene was a strong natural inhibitor of photooxidation for all light intensities at 2°C, suggesting quenching properties for singlet oxygen. However, β‐carotene antioxidant activity was reduced at 40°C because of its rapid destruction.