Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/1/2004
Publication Date: 5/4/2004
Citation: Fan, X., Sommers, C.H., Sokorai, K.J. 2004. Irradiation and antioxidants affect volatile sulfur compounds, lipid oxidation and color of ready-to-eat turkey bologna. Journal of Agricultural and Food Chemistry. 52:3509-3515. Interpretive Summary: Ionizing radiation inactivates food-borne pathogens and extends the shelf life of raw meat and processed meat products. However, irradiation can induce the development of an off-odor at high doses in certain products, especially notable in ready-to-eat products because they are routinely consumed without further processing. A study was conducted to explore the use of the natural and synthetic antioxidants including rosemary extract, nitrite and a vitamin C isomer, to reduce irradiation-induced formation of off-odor compounds (volatile sulfur compounds) and lipid oxidation in turkey bologna during an 8-week storage study. Our results suggest that the antioxidants added in the meat mixtures used for the manufacture of turkey bologna had limited effects on the production of volatile sulfur compounds due to irradiation. However, rosemary extract and nitrite significantly reduced lipid oxidation. The information is useful for processed food industry to develop strategies to control off-odor development in products exposed to ionizing radiation.
Technical Abstract: Bologna was processed from ground turkey breast meats containing one of four antioxidant treatments (none, rosemary extract, sodium erythorbate, and sodium nitrite). After cooking, the bologna were sliced, sealed in gas impermeable bags and exposed to 0, 1.5 and 3.0 kGy gamma radiation, and then stored at 5 degree C for up to 8 weeks. Thiobarbuturic acid reactive substances (TBARS), color and volatile sulfur compounds were measured every two weeks during storage. Irradiation had no consistent effect on TBARS values. Rosemary extract and sodium nitrite inhibited, while erythorbate increased, TBARS values, independent of radiation dose or storage time. Irradiation promoted redness and reduced yellowness of non-irradiated control bologna at week 0 and 2. Use of nitrite and rosemary extract inhibited the changes in color due to irradiation. Several volatile sulfur compounds (hydrogen sulfide, methanethiol, methyl sulfide, and dimethyl disulfide), measured using a pulsed flame photometric detector, increased with radiation dose. However, none of the antioxidants had any substantial effect on volatile sulfur compounds induced by irradiation. Our results suggest that antioxidants did not consistently affect irradiation-induced volatile sulfur compounds of turkey bologna although significantly impacted color and lipid oxidation.