Abstract: The stress-relaxation curves of four kinds of food materials such as ham (hard), cheese (soft), Lateolabrax japonicas (fish) and whelk (shellfish) were analyzed by nonlinear curve fitting method and the results were compared with those obtained by successive approximation method. The results suggested that the nonlinear curve fitting method could fit the generalized Maxwell model with steady and credible results. In addition the method had the advantages of high fitting degree, ease of operation and swiftness and was suitable to analyze stress-relaxation data of a variety of food materials. Moreover, the method was superior to the successive approximation method for fish and other food materials with a high water content and complicated viscoelasticity.

Key words: nonlinear curve fitting, food, stress-relaxation, Maxwell model