The invention relates to new asparaginases having improved properties, preferably improved thermotolerance, such as improved activity at high temperatures and/or improved thermostability. The invention also relates to DNA sequences encoding such improved asparaginases, their production in a recombinant host cell, as well as methods of using the asparaginases, in particular for reduction of acrylamide in foods. The invention furthermore relates to methods of generating and preparing asparaginase variants having improved properties.