Development and Validation of Analytical and Physical Testing Methods to Evaluate the Irradiation History of Animal Feeds

摘要 在过去的十年里，食用进口辐照鸡干的狗只出现了无数的疾病和死亡案例 治疗，并在澳大利亚的猫中同时爆发神经疾病和死亡，这些猫喂食辐照食物，提高了 注意辐照后的宠物食品的安全性。虽然实际原因尚不清楚，但确定总数 为了确保产品在安全范围内加工，辐射剂量是无价的。在已建立的方法中 辐照食品中2-烷基环丁酮(2-ACBS)的GC-MS分析和纤维素的分析 用电子顺磁共振(EPR)谱研究碳酸盐自由基是最有前途的方法 目的：测定宠物食品中的辐照历史。拟议研究的目标是开发GC-MS和EPR 用于量化特定辐射标志物的形成并确定其总量的技术 宠物食品和食品中的辐照处理。我们将分两部分实施该项目：前三年 致力于测试方法的开发和验证；最后两年将比较和现场测试 宠物食品辐照历史评估的验证方案。在项目的第一部分，宠物食品 产品包括鸡肉干、红薯、狗肉(啤酒、羊肉)、骨头、蹄子和猪耳朵。 用铯-137源和电子束(电子束)从0.1-75kGy射线照射。它的形成和稳定性 在前面工作的基础上，我们将使用GC-MS技术对各种2-ACB(即2-DCB、2-TCB、2-TDCB)进行评价 与Vet-LIRN和美国农业部实验室合作。同时，碳基和纤维基的形成和稳定性 将在低流动性和高流动性环境中使用EPR分析进行评估。对EPR的补充 此外，还将使用定量聚合酶链式反应(QPCR)分析来调查辐射特异性DNA损伤。分析性和 物理方法将被验证用于不同的产品配方，具有不同的脂肪成分，水分含量， 是否含有甘油、蔬菜、植物化学物质等，以及提取方法，如正己烷萃取法、固相萃取法 萃取(SPE)、固相微萃取(SPME)、索氏萃取。其化学稳定性和热稳定性 特定的辐照标记将在温度范围(20-80°C)和至少一年的室内储存时间内进行分析 温度。在该项目的第二部分，将在商业辐照宠物食品上测试经过验证的方案 可在市场上购买的产品。最后，我们将比较和对比从物理和 分析技术。总体而言，在项目结束时，我们将提出经过验证和测试的协议，这些协议可以使用 作为标准化技术来量化各种宠物食品中的辐射剂量。

Abstract Over the last decade, numerous cases of illness and death in dogs, which consumed imported irradiated chicken jerky treats, and in parallel outbreak of neurological disorders and deaths in cats in Australia, which fed irradiated food, raised attention to the safety of the irradiated pet food products. Although the actual cause is still unknown, determining the total irradiation dose is invaluable to ensure the products are processed within the safe limits. Among the methods established for the detection of irradiated foods, analysis of 2-alkylcyclobutanones (2-ACBs) with GC-MS and analysis of cellulosic and carbonate radicals with electron paramagnetic resonance (EPR) spectroscopy serve as the most promising approaches to determine the irradiation history in pet food products. The goal of the proposed research is to develop GC-MS and EPR techniques coupled to quantify the formation of specific irradiation markers and to determine the total amount of irradiation treatment in pet foods and treats. We will carry out the project in two parts: the first three years will be dedicated to development and validation of testing methods; the last two years will be the comparison and field-testing of the validated protocols for evaluation of the irradiation history in pet food products. In the first part of the project pet food products, including chicken jerky treats, sweet potato treats, dog chews (beer, lamb), bones, hoofs and pig ears, will be irradiated from 0.1-75 kGy with either a Cesium-137 source and electron beam (e-beam). The formation and stability of various 2-ACBs (i.e., 2-DCB, 2-TCB, 2-TDCB) will be evaluated using GC-MS techniques based on our previous works in collaboration with Vet-LIRN and USDA labs. In parallel, formation and stability of carbonic and cellulosic radicals will be evaluated by using EPR analysis in both low mobility and high mobility environments. Complementary to EPR measurements, irradiation-specific DNA damage will also be investigated by using qPCR analysis. The analytical and physical methods will be validated for different product formulations with varying lipid composition, moisture content, presence of glycerin, vegetables, phytochemicals etc., and extraction methods, such as hexane extraction, solid phase extraction (SPE), solid phase microextraction (SPME), soxhlet extraction. The chemical and thermal stabilities of the specific irradiation markers will be analyzed over a temperature range (20-80 °C) and at least one year of storage at room temperature. In the second part of the project, validated protocols will be tested on commercial irradiated pet food products available in the market. Eventually, we will compare and contrast the results obtained from physical and analytical techniques. Overall, at the end of the project we will propose validated and tested protocols, which can be used as standardized techniques to quantify the irradiation doses in various pet food products.