RHEOLOGICAL CHARACTERIZATION OF KETCHUP

Ketchup flow properties were investigated with a concentric cylinder viscometer in the temperature range from 30°C to 80°C. A partial characterization of the product viscoelastic behavior at 30°C was also made by “Strain test” and “Frequency test.” The Harper and El Sahrigi equation (ηa= acβ eEa/RT), as well as the equation that links the apparent viscosity of ketchups to the serum viscosity and to the pulp content (ηa=ηserum+A(%P)B), do not describe adequately the ketchup flow behavior that we found to be highly affected by the production technology and by the raw materials used.