Watanabe Hiroko, Akaboshi Chie, Saita Kiyotaka, Sekido Haruko, Hashiguchi Shigeki, Watabe Kenjiro, Tanaka Kouki
Chemistry Division, Kanagawa Prefectual Institute of Public Health, Chigasaki-shi, Kanagawa, Japan.
Shokuhin Eiseigaku Zasshi. 2011;52(1):71-7. doi: 10.3358/shokueishi.52.71.
The old ELISA method for detection of allergenic substances (egg and milk) in Kanagawa prefecture from 2003 to 2007, employed before improvement of the food allergen labeling system, yielded detection rates of 20% for egg and 30% for milk. In 2005, after improvement of the labeling system, the detection rate using the new ELISA in solutions containing 1% SDS and 7% 2-mercaptoethanol increased by about 10% for egg, but decreased by half for milk. There were 4 positive samples (over 10 µg/g) for both egg and milk proteins, on account of contamination by ingredients at the manufacturing line and the lack of proper food labeling. In 2009, the contamination levels of egg and milk proteins in labeled commercial foods were low. In a comparison between the new and old methods with the same samples, both the new ELISA and Western-blot analyses showed an increase in the detection rate of egg protein. In relation to milk protein, the detection rates were decreased with the new ELISA, although the ELISA detection rate and consistency rates with Western-blot analysis were increased. On the other hand, in the case of a protein content below 5 µg/g, it was impossible to determine ovomucoid and casein by Western-blot analysis.
2003年至2007年在神奈川县使用的旧ELISA方法用于检测致敏物质（鸡蛋和牛奶），该方法在食品过敏原标签系统改进之前采用，鸡蛋的检测率为20%，牛奶的检测率为30%。2005年，在标签系统改进后，在含有1%十二烷基硫酸钠和7%2-巯基乙醇的溶液中使用新ELISA方法，鸡蛋的检测率提高了约10%，但牛奶的检测率下降了一半。由于生产线中成分的污染和缺乏适当的食品标签，有4个鸡蛋和牛奶蛋白的阳性样本（超过10微克/克）。2009年，标签化商业食品中鸡蛋和牛奶蛋白的污染水平较低。在对相同样本的新旧方法比较中，新ELISA和蛋白质印迹分析均显示鸡蛋蛋白的检测率有所提高。对于牛奶蛋白，新ELISA方法的检测率下降，尽管ELISA检测率和与蛋白质印迹分析的一致性率有所提高。另一方面，在蛋白质含量低于5微克/克的情况下，通过蛋白质印迹分析无法确定卵类粘蛋白和酪蛋白。
