Inhibition of lipid oxidation and dynamics of polyphenol content in mechanically deboned meat supplemented with sea buckthorn (Hippophae rhamnoides) berry residues

Mechanically deboned meat (MDM) contains about 10 times more polyunsaturated fatty acids (PUFAs) and also more hemoproteins than hand deboned meat (HDM) and is essentially more susceptible to both chemical and biochemical oxidation. The oxidation, leading to the formation of potentially mutagenic and carcinogenic derivatives of PUFAs, can be inhibited by berry extracts rich in antioxidant polyphenols. Using the 2-thiobarbituric acid reactive substances (TBARS) method, we have established that the ethanol slurry of the juice-free solid residue of sea buckthorn (Hippophae rhamnoides - SB) berries inhibits oxidation of unsaturated fatty acids, of both chicken and turkey MDM. The polyphenols, mainly flavonols, responsible for this inhibition, are comparatively stable during short-term cooking and 6-day storage of cooked SB-MDMs at +6 degrees C. About half of the polyphenols are lost, obviously oxidised, during the storage of the uncooked samples of turkey 2%SB-MDM at +6 degrees C. The loss of polyphenols is much smaller in the case of chicken MDM, which is characterised by an in situ lower content of fatty acids, including the polyunsaturated ones. The liquid chromatography-diode array detection-tandem mass spectrometry (LC-DAD-ESI-MS/MS) method was used for identification and ranking of the potent polyphenolic antioxidants in the berry residue. (C) 2007 Elsevier Ltd. All rights reserved.