The secret ingredient, Mishima beef, is raised on a small island off of Japan. Only 20 heads were available this season. It's also called the best Kobe beef in the world. Each head cost 12,000 dollars a piece, so the amount of beef is limited for the battle (fillet, sirloin, ribs).
Although four Iron Chefs are shown in the opening credits, the challenger is only given the choice between three of the Iron Chefs. Iron Chef Italian is not introduced by Kaga for her to choose.
The Fine Living Network's alternative production number for this episode is FLIRN-112.
Fukui Kenji: Where's the Mishima Beef?
This refers to a famous 80's ad campaign for Wendy's fast food hamburgers. Elderly actress, Clara Peller, would stare at competitor's burgers and ask, "Where's the beef?" The saying quickly caught on and became a marketing sensation.