Haake viscotester iq rheometer

The rheological characterization of these hydrogels was tested with a rotational rheometer (HAAKE Viscotester iQ Rheometers, Thermo Scientific, Walthman, MA, USA). The lineal visco-elastic range of the hydrogels was tested first to determine an appropriate strain value. Next, the viscoelastic moduli G′ and G″ were evaluated as functions of temperature, time, and frequency separately. Each group had three replicate samples.

The rheological properties for optimising the CSMA-2 formulations were analysed using HAAKE Viscotester iQ Rheometers (Thermo Scientific, Walthman, MA, USA). A rotational shear test with a controlled shear stress from 1 to 1000 Pa was performed at 20 °C for 300 s. The data were analysed with HAAKE RheoWin software (Thermo Scientific, Walthman, MA, USA).

The texture parameters of the yoghurt curds (firmness, consistency and cohesive strength) were measured using a BDO-FB0.5TS universal testing machine (Zwick GmbH and Co., Ulm, Germany). The yoghurt curds were prepared in a dedicated beaker (50 mm in diameter and 150 mm high). For each yoghurt curd, two yoghurt samples were prepared and tested after approximately 20 h of storage at 4–6 °C. A beaker with the sample was centrally placed under the plunger of the apparatus with a cylindrical die 45 mm in diameter and 5 mm in height, and then compressed to a depth of 25 mm at a speed of 1 mm/s. On the basis of the force-time curves obtained, the following texture characteristics were determined for the curds: firmness—the maximum positive force (N), consistency—the positive area of the curve up to the maximum point (mJ) and cohesive strength—the maximum negative force (N). The measurements were taken in duplicate. The results of the measurements were processed using TestXpert® II software (2011, Zwick GmbH and Co, Ulm, Germany). Rheological measurements—dynamic viscosity (mPa·s) were conducted using the HAAKE Viscotester iQ rheometer (Thermo Fisher Scientific, Walthman, MA, USA) equipped with an cylindrical rotor. The measurements were taken in duplicate, at 10 °C.