# Isolation and Characterization of Starch from Different Potato Cultivars Grown in Croatia
## 3 Results and Discussion
### Paste Properties by [PERSON]'s Micro Visco-Amylograph  
Among all commercial starches, potato starch has the highest swelling power and provides the highest viscosity of starch pasting properties ([PERSON] et al., 2018). [PERSON] et al. (2018) concluded that the thermodynamic melting properties of starches are directly correlated with the amylose content. The pasting properties of starch are usually determined based on changes in the starch viscosity. The results of the properties of the pastes determined using [PERSON]'s micro visco-amylograph are shown in Table 4. The highest peak viscosity value was found in the starch sample obtained from the Scala cultivar 1673.5 \(\pm\) 20.5 BU, while the lowest value was in the starch sample obtained from the Stilleto cultivar 1410.0 \(\pm\) 2.8 BU. After shearing at 92 \({}^{\circ}\)C, the viscosity of all eight potato cultivars decreased because the structure of the paste was damaged due to shearing. Cooling to 50 \({}^{\circ}\)C showed an increase in the viscosity of the potato starch paste.  
According to [PERSON] et al. (2019), the increase in viscosity during cooling occurs due to retrogradation--that is, the connection of dissolved starch molecules. Breakdown, which indicates the stability of the starch paste during shearing at high temperatures, is calculated  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **Peak Viscosity** & **Viscosity at** & **Viscosity after** & **Viscosity at** & **Viscosity after** & **Breakdown** & **Serback** \\  & **[BU]** & **92 \({}^{\circ}\)C [BU]** & **Shearing at** & **50 \({}^{\circ}\)C** & **Shearing at** & **50 \({}^{\circ}\)C** & **[BU]** & **[BU]** \\ \hline Saprodi & 1505.5 \(\pm\) 33.2 b  & 1130.5 \(\pm\) 6.4 d  & 600.0 \(\pm\) 2.8 f  & 1046.0 \(\pm\) 18.4 e  & 854.5 \(\pm\) 13.4 e  & 905.5 \(\pm\) 30.4 a  & 446.0 \(\pm\) 15.6 d  \\ Sofista & 1499.5 \(\pm\) 19.1 b  & 1016.0 \(\pm\) 7.7 d  & 539.0 \(\pm\) 8.5 d  & 92.54 \(\pm\) 3.5 c  & 758.5 \(\pm\) 0.7 e  & 960.5 \(\pm\) 27.6 b  & 385.5 \(\pm\) 4.9 b  \\ Stilleo & 1410.0 \(\pm\) 2.8 a  & 1006.0 \(\pm\) 18.4 d  & 514.5 \(\pm\) 12.0 c  & 898.0 \(\pm\) 18.4 c  & 745.5 \(\pm\) 33.2 c  & 895.5 \(\pm\) 9.2 a  & 383.5 \(\pm\) 6.4 b  \\ Dartiest & 1446.5 \(\pm\) 9.2 a  & 904.5 \(\pm\) 16.3 b  & 468.0 \(\pm\) 7.1 a  & 834.5 \(\pm\) 19.1 b  & 693.0 \(\pm\) 11.3 b  & 978.5 \(\pm\) 2.1 b  & 366.5 \(\pm\) 12.0 b  \\ Sereno & 1418.5 \(\pm\) 21.9 b  & 1048.0 \(\pm\) 11.3 b  & 562.5 \(\pm\) 6.4 b  & 962.5 \(\pm\) 19.1 d  & 799.0 \(\pm\) 15.6 d  & 956.0 \(\pm\) 28.3 b  & 400.0 \(\pm\) 12.7 c  \\ Senta & 1490.0 \(\pm\) 1.4 b  & 888.5 \(\pm\) 9.2 a  & 487.0 \(\pm\) 4 b  & 865.5 \(\pm\) 6.4 b  & 641.5 \(\pm\) 100.6 a  & 1003.0 \(\pm\) 5.7 d  \\ Scala & 1673.5 \(\pm\) 20.5 c  & 974.0 \(\pm\) 9.9 c  & 521.0 \(\pm\) 4.2 c  & 915.0 \(\pm\) 4.2 c  & 738.0 \(\pm\) 4.2 c  & 1152.5 \(\pm\) 16.3 e  & 94.0 \(\pm\) 0.0 c  \\ S13–25 & 1519.0 \(\pm\) 9.9 b  & 870.0 \(\pm\) 9.9 a  & 474.0 \(\pm\) 5.7 a  & 796.0 \(\pm\) 0.0 a  & 796.0 \(\pm\) 0.0 a  & 663.0 \(\pm\) 7.1 a  & 1045.0 \(\pm\) 4.2 d  & 322.0 \(\pm\) 5.7 a  \\ \hline \end{tabular}
\end{table}
Table 4: Pasting properties of the isolated potato starches.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample** & **L*** & **a*** & **b*** & **C** & **h*** \\ \hline Saprodi & 94.85 \(\pm\) 0.31 c  & \(-\)1.45 \(\pm\) 0.19 a [FOOTNOTE:a]Footnote d:from the difference in the viscosity value after 15 min of mixing at 92 \({}^{\circ}\)C, and the peak viscosity value. The Scala cultivar had the highest breakdown value, which indicates that it is less stable during shearing at high temperatures. The cultivars Senata and SL 13-25 had similar breakdown values. From the setback results, which indicate the tendency of starch paste to retrograde, it is noticeable that the starch obtained from the Saprodi cultivar is slightly more susceptible to retrogradation compared to the other starches.