# Influence of Plant-Based Structuring Ingredients on Physicochemical Properties of Whey Ice Creams
## 2 Materials and Methods
### Characterization of Ice Cream Mixes  
Total solid content was determined by the arbitration method. This involves drying an ice cream mix sample diluted with distilled water and mixed with sand at 102 \({}^{\circ}\)C until a constant mass is achieved. The residue is then weighted to determine the total solid content. The fat content was determined by the adapted Gerber method [37]. Briefly, this method measures fat using a butyrometer containing sulfuric acid and isoamyl alcohol, which produces a reaction and provides a reading of the fat percentage. The protein content was quantified using the Kjeldahl method [38], a three-step approach involving digestion, distillation, and titration to determine the protein content. The viscosity of whey ice cream mixes was measured with an ultrasonic viscometer (UNIPAN, model 305, Warsaw, Poland). Before each measurement, the level of the ultrasonic signal was checked. The measuring probe of the magnetostrictive vibrator was completely immersed in the ice cream mix. The induced ultrasonic waves were damped by the test material, and the results were displayed as the product of viscosity and density in units of mPa \(\times\) s \(\times\) g \(\times\) cm\({}^{-3}\). Viscosity was determined at 20 \({}^{\circ}\)C [39]. Viscoelastic behavior measurements of ice cream mixes were conducted using plate geometry on a Kinexus lab+ device (Malvern, UK). Two serrated plates with a diameter of 0.044 m were used to minimize the slippage effect, and the gap between them was 0.002 m. The tests were performed in the range of 0.1-10.0 Hz at a strain of 0.01%, and changes in the storage (G\({}^{\prime}\)) and loss (G\({}^{\prime\prime}\)) moduli, as well as the phase angle (\(\phi\)), were recorded. The research was conducted at 25 \({}^{\circ}\)C. The measurement results were registered on a computer in the Kinexus Malvern--Space program [40]. Surface tension was measured with a KSV Sigma 700 tensiometer (KSV Instruments, Ltd., Finland). This device registers and analyzes the forces acting on the sample using sensitive microbalances. The force registered by the scales is directly converted to surface tension using a platinum de Nooy ring. The dynamic surface tension was calculated using the Sigma 700 Force software complex. Before each analysis, the de Nooy ring was cleaned with distilled water and dried under a flame. \begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline \multirow{2}{*}{**Ingredient**} & \multicolumn{8}{c}{**Content (\%)**} \\ \cline{2-10}  & **S.1** & **S.2** & **S.3** & **S.4** & **S.5** & **S.6** & **S.7** & **S.8** & **S.9** \\ \hline Whey powder & 7.0 & 7.0 & 7.0 & 7.0 & 7.0 & 7.0 & 7.0 & 7.0 & 7.0 \\ \hline White sugar & 17.0 & 17.0 & 17.0 & 17.0 & 17.0 & 17.0 & 17.0 & 17.0 & 17.0 \\ \hline Stabilization system & 0.4 & 0.4 & 0.4 & 0.4 & 0.4 & 0.4 & 0.4 & 0.4 \\ \hline Oat \(\beta\)-glucan & – & 0.75 & – & – & – & – & – & – & – \\ \hline Yeast \(\beta\)-glucan & – & – & 0.5 & – & – & – & – & – \\ \hline Protein complex & – & – & – & 3.0 & 4.5 & 3.0 & 4.5 & 3.0 & 4.5 \\ \hline Beet & – & – & – & 10.0 & 10.0 & – & – & – & – \\ \hline Broccoli & – & – & – & – & – & 10.0 & 10.0 & – & – \\ \hline Zuchinni & – & – & – & – & – & – & 10.0 & 10.0 \\ \hline Water & 75.60 & 74.85 & 75.10 & 62.60 & 61.10 & 62.60 & 61.10 & 62.60 & 61.10 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Whey ice cream formulations. Water activity (aw) was measured using an AWMD-10 water activity meter (NAGY, Gaufelden, Germany) with an accuracy of \(\pm\)0.001 aw unit. Prior to measurement, the device was calibrated according to a special humidity standard (95% HR). Measurements were performed at 20 \({}^{\circ}\)C.  
A sensory analysis was carried out in accordance with ISO 22935-3:2009 [41]. The analysis considered the following sensory indicators: color, appearance, aroma, consistency, and taste.