Chitosan was added to tofu prepared with different curdling agents. The properties of tofu depended on the curdling agents, chitosan content, and the degree of deacetylation (DD) of chitosan. The addition of 2% chitosan increased the gel strength of tofu for 5-305% and its shelf life for 2-10 days. Chitosan changed the water content of tofu slightly. The gel strength of tofu containing chitosan decreased with increasing DD. The shelf life of tofu increased with increasing DD of chitosan. Chitosan caused the smallest change in the gel properties of tofu prepared with glucono-delta-lactone, but it affected the tofu prepared with acetic acid the most. (C) 2003 Elsevier Science Ltd. All rights reserved.