Does eating eggs invalidate ablution, and is it obligatory to say the Takbir before cooking them?

The nullifiers of ablution are limited and well-known. Eating eggs does not nullify ablution by consensus, whether before or after cooking. Indeed, there is a scholarly consensus that ablution is not obligatory for that which has been touched by fire. As for saying "Allahu Akbar" before cooking eggs, there is no basis for it in Islamic law, and it is an innovation.