CHEMILUMINESCENCE AS A METHOD FOR OXIDATIVE RANCIDITY ASSESSMENT IN AUTOXIDIZED MARINE OILS

Chemiluminescence based on light emission from excited oxygen species, eg. singlet oxygen and triplet carbonyls, has been used to measure the oxidative rancidity of fish oils. The luminescence was recorded after sodium hypochlorite addition to the oils dissolved in tert-butanol. In addition to high sensitivity and ability to detect small changes in rancidity, the method is fast and may be used as a supplement to the standard chemical methods for quality assessment and antioxidant evaluation. However, care has to be taken in interpretation of the chemiluminescence data of different fish oils, as the light emission depends on both the composition and the rancidity level of the oil. The autoxidized oils were also characterized by peroxide value, thiobarbituric acid value, anisidine value, Kreis rancidity index, iodine value, ultraviolet measurements, capillary gas chromatography, size-exclusion chromatography and sensoric evaluation.