There is no food that is exactly banned in space. A lot of food is discouraged from being taken in space. There are strategic reasons for not taking such foods to space or simple astronauts crying that they taste better on Earth.
Bread: Didn’t expect this, did you? Well, your space journey definitely won’t have ham sandwiches on the menu. Bread isn’t taken due to zero gravity’s behavior. Small Breadcrumbs might get into astronauts’ eyes, or sensitive machinery that can spoil space missions.
Pizza: Yeah! I do personally hate this but there has only been one pizza in space. Pizza Hut delivered pizza in space and it tasted terrible. It doesn’t have the crunch and tends to be soggy so astronauts themselves rejected it.
Salt and Pepper: Salt and Pepper are a big no-no. Simple reason being they can’t be sprinkled. Zero Gravity folks! It will mess you up more than you think. There is liquified salt and pepper though.
Chips: This is pizza all over again, A HUGE DISAPPOINTMENT! Astronauts themselves hate taking chips in space because of inability to eat them. It’s tough eating chips in space.
Soft drinks: Even, Pepsi is not allowed in space. Carbonated drinks cause you to vomit in space because burping in space is not possible as gas cannot separate from food due to the absence of gravity. So when you try to burp, you will cause food to come out with it. Eww!
Alcohol: It was allowed. The Russians had too much fun with it. But there was much resentment and USA was the first to ban alcohol in space. Although beer specifically for space is being made by some scientists.
There are a number of foods that are banned in space for different reasons. The first of which is bread and similar products. The reason for this ban is because crumbs can break off and float away into astronauts' eyes and interfere with equipment. Soda is also banned, they are hard to ingest and once they have been swallowed they tend to make astronauts vomit when burping due to the gas.
Salt, pepper and spices are banned for the same reason bread is. Fresh milk is not allowed because it requires refrigeration, instead dehydrated milk is used. Likewise, ice cream isn't acceptable because it melts, however, freeze dried ice cream is acceptable. The last two banned items are pizza and alcohol. Pizza has been eaten in space once but the crust doesn't get crispy and alcohol is banned because of the Russians abusing it.