Active oxygens generated from heat-browned beef: determination by the chemiluminescence of a cypridina luciferin analogue, 2-methyl-6-(P-methoxyphenyl)-3,7-dihydroimidazo [1,2-a] pyrazin-3-one

摘要

2-Methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one (MCLA), a Cypridina luciferin analogue, emits photons reacted with superoxide and singlet oxygen. When the water extract of a heat-browned beef sample was added to the solution containing MCLA a high chemiluminescence was observed. The development of the chemiluminescence necessitated the presence of oxygen. The light emission was effectively suppressed by 68% with the addition of superoxide dismutase (SOD). The inhibition rate of the chemiluminescence by sodium azide was 45%. Ascorbic acid inhibited the chemiluminescence by 97%. These observations indicated the possible generation of superoxide, singlet oxygen and free radicals from the extract of heat-browned beef sample. The generation of these active oxygens and free radicals from the heat-browned beef are discussed in comparison with the previously reported findings that active oxygen species and free radicals are formed in broiled beef and other heat-browned food materials.