46C-1 |
Verification of a monoclonal CI-ELISA for monitoring lipid oxidation in chicken |
C. F. ROSS1, J. J. Pestka1, R. M. Beaudry2, and D. M. Smith3. (1) Dept. of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824, (2) Dept. of Horticulture, Michigan State University, East Lansing, MI 48824, (3) Dept. of Food Science and Toxicology, University of Idaho, Moscow, ID 83844 Lipid oxidation is a major quality deterioration problem for all muscle foods, thus, the meat industry needs a sensitive and rapid method to detect lipid oxidation. Hexanal, a secondary product of lipid oxidation, has often been used as in indicator of lipid oxidation. Headspace-gas chromatography has typically been used to measure hexanal; however, this method is expensive and involved. As a sensitive, rapid and reproducible alternative, a monoclonal antibody was developed for the detection of hexanal. Our objective was to compare the ability of two assys for hexanal, a monoclonal CI-ELISA and a solid-phase microextraction gas chromatography/mass spectrometry (GC/MS-SPME) method, and a thiobarbituric acid reactive substances assay (TBARS) for monitoring lipid oxidation in freeze-dried chicken protein. Freeze-dried myofibrils (MF) with added methyl linoleate (0.6 mmol/g protein) were stored at 50°C at water activities (Aw) of 0.30 and 0.75 in replicated experiments. Samples were removed each day over a 5 day storage period. Hexanal was measured by GC/MS-SPME and CI-ELISA. Lipid oxidation was also analyzed by TBARS. Lipid oxidation occurred more rapidly, and higher concentrations of hexanal and TBARS were observed, when MF were stored at the higher Aw (p<0.05). Lipid oxidation reached a maximum after 4 days of storage at both Aw (p<0.05), then decreased. After 4 days of storage at Aw 0.30, 34.7 and 39.7 ppm hexanal were detected by GC/MS-SPME and CI-ELISA, respectively. The CI-ELISA was well correlated with the GC/MS-SPME (r2=0.78) and TBARS (r2=0.87) methods. The correlation of the hexanal-specific CI-ELISA to both GC/MS-SPME and TBARS verified the ability of this assay to be used as an index of lipid oxidation. In addition to the ease of use, low cost and high sensitivity of the CI-ELISA, it also offers the convenience for use in a kit, which can easily be utilized within a food processing facility.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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