A vegetable is the edible component of a plant including leaves, stalks, roots, tubers, bulbs, flowers and seeds. In mushrooms, the fruiting body is usually the organ of interest. With the exception of certain seeds, plant tissues are low in protein. Water, fibre, starch, certain vitamins, minerals and some lipids are the principal components. In general, the pH of vegetable tissue is in the range 5–7. Since the overall composition and pH are very favourable, growth of numerous microbial species can be expected if adequate moisture is present.