Sommers Christopher H, Fan Xuetong, Handel A Phillip, Baxendale Sokorai Kimberly
Food Safety Intervention Technologies Research Unit, US Department of Agriculture, Agricultural Research Service, NAA, Eastern Regions Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038, USA.
Meat Sci. 2003 Mar;63(3):407-15. doi: 10.1016/s0309-1740(02)00100-6.
Listeria monocytogenes is a common contaminant of ready-to-eat meat products, including frankfurters. Ionizing (gamma) radiation can eliminate L. monocytogenes from frankfurters. Citric acid (CA) is an antioxidant synergist and anti-microbial agent that can be applied to the surfaces of cured meat products prior to packaging. The effect of CA on the radiation resistance of L. monocytogenes that was surface-inoculated onto frankfurters was determined. The D(10) values, the radiation doses required to inactivate 90% of viable L. monocytogenes, were 0.61, 0.60, 0.54, and 0.53 kGy, on frankfurters dipped in 0, 1, 5 or 10% CA solution, respectively. CA, although an antioxidant synergist, did not increase antioxidant activity (AA) on frankfurter surfaces as determined by the ferric reducing antioxidant power (FRAP) assay. Lipid oxidation, as determined by the Thiobarbituric acid reactive substances (TBARS) assay, was not affected by CA or ionizing radiation. Color of frankfurters, determined by Hunter L, a, b, indicated that ionizing radiation induced a small, but visually imperceptible, loss of redness (a-value). Frankfurter firmness, as measured by maximum shear force, was not affected by ionizing radiation or CA. CA enhanced the lethality of ionizing radiation without negatively impacting frankfurter color, lipid oxidation, firmness, or antioxidant activity.
单核细胞增生李斯特菌是即食肉类产品（包括法兰克福香肠）中常见的污染物。电离（γ）辐射可消除法兰克福香肠中的单核细胞增生李斯特菌。柠檬酸（CA）是一种抗氧化增效剂和抗菌剂，可在包装前应用于腌制肉类产品的表面。测定了CA对表面接种在法兰克福香肠上的单核细胞增生李斯特菌辐射抗性的影响。D(10)值（即灭活90%存活单核细胞增生李斯特菌所需的辐射剂量）在分别浸泡于0%、1%、5%或10%CA溶液中的法兰克福香肠上分别为0.61、0.60、0.54和0.53千戈瑞。通过铁还原抗氧化能力（FRAP）测定法确定，CA虽然是一种抗氧化增效剂，但并未增加法兰克福香肠表面的抗氧化活性（AA）。通过硫代巴比妥酸反应物质（TBARS）测定法确定的脂质氧化不受CA或电离辐射的影响。通过亨特L、a、b测定的法兰克福香肠颜色表明，电离辐射导致红色度（a值）略有下降，但肉眼难以察觉。通过最大剪切力测量的法兰克福香肠硬度不受电离辐射或CA的影响。CA增强了电离辐射的致死性，而不会对法兰克福香肠的颜色、脂质氧化、硬度或抗氧化活性产生负面影响。
