How does the consciousness of the cook affect prasad?

From: Sripad Mahaprabhu das

I have heard that consciousness of the cook enters the food and is transferred to the person who eats it. Does this also holds true in case of devotee cooks?

How can prasad have consciousness of the cook when it is completely purified by the glance of the Lord Himself? Will not consciousness of Lord override the consciousness of cook?

Please answer with some scriptural reference. Thank you.