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

摘要 在过去的十年中，许多病例的疾病和死亡的狗，食用进口辐照鸡肉干 治疗，并在平行爆发的神经系统疾病和死亡的猫在澳大利亚，其中喂养辐照食品，提高 注意辐照宠物食品的安全性。虽然真正的原因还不清楚，但确定总数 辐照剂量对于确保产品在安全范围内加工非常重要。在所建立的方法中， 用于辐照食品的检测，用GC-MS分析2-烷基环丁酮（2-ACB）和分析纤维素 电子顺磁共振（EPR）光谱和碳酸根作为最有前途的方法 以确定宠物食品中的辐照历史。本研究的目的是发展GC-MS和EPR 技术耦合，以量化特定的辐射标记物的形成，并确定总的量， 宠物食品和零食中的辐照处理。我们将分两部分实施该项目：前三年将 致力于开发和验证测试方法;最后两年将是比较和实地测试， 宠物食品辐照历史评价的验证方案。在项目的第一部分宠物食品 产品，包括鸡肉干零食，红薯零食，狗咀嚼物（啤酒，羊肉），骨头，蹄子和猪耳朵，将被 用铯-137源和电子束（e束）进行0.1-75 kGy的辐照。的形成和稳定性 各种2-ACB（即，2-DCB，2-TCB，2-TDCB）将在我们以前工作的基础上使用GC-MS技术进行评价 与Vet-LIRN和USDA实验室合作。同时，碳和纤维素自由基的形成和稳定性 将在低流动性和高流动性环境中使用EPR分析进行评估。补充EPR 除了测量之外，还将通过使用qPCR分析来研究辐射特异性DNA损伤。的分析和 将对具有不同脂质组成，水分含量， 甘油、蔬菜、植物化学物质等的存在，和萃取方法，如己烷萃取、固相萃取 固相萃取（SPE）、固相微萃取（SPME）、索氏萃取。的化学和热稳定性， 将在温度范围（20-80 °C）内分析特定辐照标记物，并在室温下储存至少一年 温度在该项目的第二部分，验证协议将测试商业辐照宠物食品 市场上的产品。最后，我们将比较和对比从物理和 分析技术。总的来说，在项目结束时，我们将提出经过验证和测试的协议，可以使用 作为量化各种宠物食品中辐照剂量的标准化技术。

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.