Ij 44c glass electrode

Rheological measurements were carried out with a Brookfield DV-III V3.3 RV rotary viscometer (U.S.A.) at 22 °C in the shear rate range of 1–30 s⁻¹ using an RV-29 mandrel.
Quantities of 13 mL of dough were subjected to shearing. The rheological measurements were made within 15 min of the preparation of the dough [6 (link)]. The measurement time for one sample was 120 s. The following rheological model was applied for the flow curve description: $${\mathsf{\tau }=\mathrm{K}\mathsf{\gamma }}^{\mathrm{n}}$$ , where: τ is the shear stress (Pa), γ is the shear rate (s⁻¹), K is the consistency coefficient (Pa·sⁿ), and n is the flow behavior index. The parameters used as criteria to select the optimal model included the coefficient of determination R².
The density was determined based on the mass and volume of the dough sample. The dough was put into a dry measuring vessel and weighed to an accuracy of 0.01 g. Measurements were performed in triplicate.
The pH value of the dough was measured using a pH meter with an IJ-44C glass electrode (Elmetron, Poland) at a temperature of 25 ± 1 °C.

pH is effectively a measure of the concentration of hydrogen ions in a substance. For pH measurements, 1 g of feed mixture was weighed, added to 9 mL of distilled water, thoroughly mixed [23 (link)], and left for 15 min. Then, its pH value was measured using a CP-401 pH meter with an IJ-44C glass electrode (Elmetron, Zabrze, Poland) at 25°C±1°C. The pH-meter was calibrated in buffers of pH 4.00, pH 7.00 and pH 9.00 at 25°C ±1°C. The measurements were made for each feed mixture sample in a group, in 6 replications.