Abstract：
Processing food and feed challenges official control e.g. by modifying proteins, which leads to significant underestimation in targeted, MS-based protein quantification. Whereas numerous studies identified processing-induced changes on proteins in various combinations of matrices and processing conditions, studying their impact semi-quantitatively on specific protein sequences might unveil approaches to improve protein quantification accuracy. Thus, 335 post-translational modifications (e.g. oxidation, deamidation, carboxymethylation, Amadori, acrolein adduction) were identified by bottom-up proteomic analysis of 37 bovine materials relevant in food and feed (meat, bone, blood, milk) with varying processing degrees (raw, spray-dried, pressure-sterilized). To mimic protein recovery in a targeted analysis, peak areas of marker and reference peptides were compared to those of their modified versions, which revealed peptide-specific recoveries and variances across all samples. Detailed analysis suggests that incorporating two modified versions additionally to the unmodified marker may significantly improve quantification accuracy in targeted MS-based food and feed control in processed matrices.
摘要：
加工食品和饲料挑战官方控制，例如通过修饰蛋白质，这导致对目标的严重低估，基于MS的蛋白质定量。尽管许多研究确定了在基质和加工条件的各种组合中加工诱导的蛋白质变化，半定量研究它们对特定蛋白质序列的影响可能揭示提高蛋白质定量准确性的方法。因此，335翻译后修饰(例如氧化，脱酰胺,羧甲基化,Amadori,通过对37种与食品和饲料相关的牛材料（肉类，骨头,血,牛奶)具有不同的加工程度(生的，喷雾干燥,压力灭菌)。为了模拟目标分析中的蛋白质回收，将标记和参考肽的峰面积与其修饰版本的峰面积进行比较，这揭示了所有样品的肽特异性回收率和差异。详细的分析表明,除了未修饰的标记物之外还掺入两个修饰的版本可以显著提高加工基质中靶向的基于MS的食品和饲料控制的定量准确性。
