The changes that occur, especially in the dietary fibre, during processing of white asparagus have been studied. Processing consists of submitting the vegetable to a treatment with hot water (96 degrees C), for 4 min (blanching) and subsequently immersing it in a sodium chloride solution (brining). Finally, the asparagus is sealed and sterilised at 115-116 degrees C. The study was performed on the whole asparagus and also, separately, on the apex and stem. As a result of processing there was an increase in the moisture and protein contents and a decrease in those of uronic acids and free sugars, saccharose disappearing entirely. It is concluded that the most important changes taking place in the asparagus fibre fraction during thermal treatments are the slight decrease of lignin and uronic acids, the slight increase in proteins and an important decrease in hemicelluloses.