Resonance Raman monitoring of lipid oxidation in muscle foods

Abstract

A non-invasive optical method, Resonance Raman spectroscopy was used to follow the progression of lipid oxidation in mechanically separated turkey (MST) through oxidative bleaching of β-carotene. Endogenous or 20-50 ppm exogenously added β-carotene in MST served as an inert marker of lipid oxidation, and the corresponding detectable Raman signals were highly correlated with the concentration of lipid oxidation products in muscle tissue based on thiobarbituric acid reactive substances (TBARS). Adding 100 ppm β-carotene accelerated lipid oxidation in MST, and thus should not be used. No carotenoid Raman response was obtained for washed cod with added hemoglobin, which indicates that washed cod was devoid of any endogenous β-carotene. Moreover, the absence of any heme protein Raman response eliminates the use of heme as an alternative biomarker to β-carotene at the excitation wavelength employed. These studies indicate that resonance Raman detection of endogenous or exogenous β-carotene can be used as a simple and non-invasive method for assessing lipid oxidation status in finely comminuted muscle tissues. © 2008 Institute of Food Science and Technology.