[Improved capability of a revised test kit, FASTKIT ELISA version II (Egg), to detect heated proteins of egg white but not egg yolk].

BACKGROUND: A kit, FASTKIT ELISA version II (Egg) (Nippon Meat Packers) is an enzyme-linked immunosorbent assay kit for detecting hen's egg proteins in foodstuffs. This kit is an enhanced version of FASTKIT ELISA (Egg) with a greater efficiency in terms of extraction of egg proteins from heated foodstuffs. However, the property of this kit remains to be fully elucidated. METHODS: Using this new kit, we measured the amount of egg proteins in unheated or heated (140 degrees C or 180 degrees C, 20 min) homemade cookies containing whole egg, egg white or egg yolk. RESULTS: The capability for detection of unheated or heated (140 degrees C or 180 degrees C) whole egg proteins was similar. In addition, there was no significant difference in the detectability between heated (140 degrees C) whole egg and egg white proteins. However, unheated or heated (140 degrees C or 180 degrees C) egg yolk proteins were not sufficiently measured by this kit. CONCLUSION: Our data suggest that this new kit is significantly improved for detection of heated egg white proteins as compared to that of old version, but not sufficient for detection of egg yolk proteins.