高效液相色谱法检测γ-射线辐照食品中的邻酪氨酸

Determination of o-Tyrosine in γ-Ray Irradiated Food by HPLC

目的:建立含蛋白质辐照食品中邻酪氨酸的柱前衍生-高效液相色谱检测方法。方法:样品经丙酮-三氯甲烷溶液净化除去脂肪和糖分,在110℃经盐酸水解过夜去蛋白后,水解液与衍生剂衍生,高效液相色谱检测,外标法定量。结果:方法最低检出限为5mg/kg,样品在5、10、50mg/kg添加水平的平均回收率为62.1%～88.3%,变异系数为3.91%～9.38%(n=6)。结论:辐照剂量在5kGy及以上的鸡肉和猪肉可以被检测出邻酪氨酸,含量明显高于空白,且邻酪氨酸含量与辐照剂量呈线性关系。辐照剂量在5kGy及以上的鸡肉和猪肉在-20℃中保存3个月后仍可以检测出邻酪氨酸。

Objective： To develop a determination method of o-tyrosine in g-ray irradiated protein-rich foods by highperformance liquid chromatography coupled with pre-column derivatization. Methods： Sample was homogenized and purified by eliminating fat and sugars with the mixture of acetone and chloroform （3：1, V/V）, and then deproteinated by means of hydrolysis with hydrochloric acid at 110℃ for 24 h. After reacting with derivative reagent, the sample digestion solution was subjected to HPLC analysis by external reference method. Results： The detection limit of o-tyrosine by this method was 5 mg/kg. The recoveries of o-tyrosine at the spiked amounts of 5, 10, and 50 mg/kg were 62.1% to 88.3%, and the coefficients of variation were 3.91% to 9.38% （n = 6）. Conclusion： The o-tyrosine content in chicken and pork irradiated with 5 kGy and above of y-ray can be successfully detected, which is obviously higher than that in unirradiated meat samples and presents linear relationship with irradiation dose. After 3-month storage at -20 ℃, the o-tyrosine is still detectable in chicken and pork irradiated with 5 kGy and above of γ-ray.