Soups in East Asian culture are eaten as one of the main dishes in a meal or in some cases served straight with little adornment, particular attention is paid to the soups' stocks. In the case of some soups, the stock ingredients become part of the soup. They are usually based solely on broths and lacking in dairy products such as milk or cream. If thickened, the thickening usually consists of refined starches from corn or sweet potatoes. Asian soups are generally categorized as either savoury or sweet. The quality of a savoury soup is determined mainly by its fragrance and umami or "xian" flavour, as well as, to a lesser extent, its mouthfeel. Sweet soups such as tong sui are enjoyed for their aroma, mouthfeel, and aftertaste. Many soups are eaten and drunk as much for their flavour as for their health benefits and touted for their purported revitalizing or invigorating effects. In Chinese language, noodle soups are generally not considered a noodle dish instead of a soup, as evidenced by the fact that they are called soup noodle (湯麵), with soup being an adjective and contrasts with dry noodle (乾麵).