Effects of food colorants on photooxidation of lipids added to Alaska pollackTheragra chalcogrammasurimi.

Food colorants including rose bengal, erythrosine B, phloxine B and cochineal extracts were added to Alaska pollackTheragra chalcogrammasurimi which was previously added with methyl linoleate (MeLe) or ethyl eicosapentaenoate (EPA Et). All the surimi were exposed to a 100-watt light tungsten bulb (4500 lux) in a cold room at 5°C. Four isomeric hydroperoxides, including 13-cis,trans-, 13-trans,trans-, 9-trans,cis- and 9-trans,trans-MeLe hydroperoxides, were generated by oxidation of MeLe added to surimi with and without cochineal extracts after exposure to light for several hours. For the surimi containing rose bengal, erythrosine B and phloxine B, extracted lipids contained not only the above four hydroperoxide isomers but also 12-cis,trans- as well as 10-trans,cis-MeLe hydroperoxides. EPA Et added to surimi which contained rose bengal, erythrosine B and phloxine B generated characteristic isomeric hydroperoxides, including 6-cis,trans- and 17-cis,trans-EPA Et hydroperoxides due to1O2 mediated oxidation. The pro-oxidative potentials of four food colorants in surimi against added EPA Et or MeLe increased as the order of cochineal extracts < phloxine B < erythrosine B < rose bengal. These results clearly demonstrated that the addition of certain food colorants to surimi accelerated1O2 mediated lipid oxidation to result in the generation of characteristic hydroperoxide isomers. [ABSTRACT FROM AUTHOR]