Abstract:
Foods are diverse and complex materials, which exhibit a wide range of different
rheological properties. Viscosity is the one of main rheological property of liquid food.
Resorting of this property in the sphere of quality control in detecting of magnitude of
suspended solid factory flow level as well as at different field level in different type of
liquid food products is important aspect. Because existing methods are time consuming,
high service charge with"expensive equipments and fatigue to the examiner.
In this study viscosity , was measured using lab scale apparatus (using Poiseuille
principal) under different temperatures ait 15°C, 25°C, 30°C, and 35°C and different
concentrations, for milk and fruit juices diluted with water and Treacle diluted with
sugar syrup by 20%, 40%, 60%, 80°/o, and 100% as Newtonian and Non-Newtonian
foods. An Electro Resistance Type (ERT) viscometer was designed and fabricated to
measure viscosity of these liquid foods at above concentrations and temperatures. The
principal of fabrication is more electric amperage is required to rotate the device at
constant speed with the increment of viscosity.
The data obtained from the ERT viscometer reading (amperage) was compared with the
viscosity value of lab scale apparatus and solid content of each food by resorting
Regression and correlation statistical test method, in order to determine correlation
between these two variables.
The Regression and correlation analysis revealed that there is positive correlation
between Electro Resistance Type Viscometer readings (amperage) and viscosity values
of Poiseuille principle as well as solid content. The linear relationship of viscosity and
ERT Viscometer reading is always more than 90% for all tested liquids in different
temperatures and concentrations. ERT viscometer is. a low cost apparatus.
