The hypo-allergenic storage protein of rice grain is tolerated by virtually all people and its use versatility is the best of all the cereal grains. Rice is the one crop that produced year round and was eaten every day during the 2-year mission of the first Biosphere 2 crew. The plants can be grown in high density in CEA and the grain is very versatile. Wheat in the form of breads and pastas is a very important and common foodstuff in many cultures. Studies have shown that the more plant foodstuffs included in a vegetarian the more palatable and satisfying the diet becomes.
Tomatoes are a very versatile seasoning that can be used in stews, sauces, and salads.
Herbs will surely be grown. With a limited number of crop species, spices and herbs will be important in making the diet seem more varied. These are inefficient to grow and impose additional problems for a spacecraft. It is possible that the yeast could be fed sugars released from the cell walls of inedible plant biomass during waste processing. Algae represent another possible dietary supplement.