Analyses were carried out at least twice in two replicated experiments; therefore each value is the average of at least four analyses. Coefficients of variation, expressed as the percentage ratio between the standard deviations and the mean values, were lower than 10 for acrylamide, weight loss and colour values, and 0.5 for total solid content.Analysis of variance was carried out and differences among means were assessed by using the Tukey or Student’s t test (STATISTICA for Windows, 5.1, Statsoft Inc., Cary, NC). Means were considered significantly different at p < 0.05.