## 3 Results and Discussion  
### Characterization of Carbohydrate Materials and Prepared Emulsions with Pumpkin Oil  
#### 3.1.1 Carbohydrate Material Properties  
The native starches selected for this study had different granule size, with rice as the smallest one followed by maize, and wheat, and these granules were characterized by different shapes observed in SEM images in Figure 1. Other carbohydrates used in the study differed significantly from used starches regarding the granule size and microstructure. It was observed that native starches have spherical shapes, similar to previously presented by [PERSON] et al. [27, 28]. [PERSON] [29] reported that size and shape of starch granules differ among plant species and can be angular, oval, round, spherical or irregular. As shown in Figure 1, rice starch particles, as well as wheat and maize, are angular in shape, and are clustered as compound granules. This type of rice starch granules aggregation was also described by [PERSON] et al. [30]. SEM images of lactose and trehalose showed that they have a similar shape, distinct from the shape of native starches and maltodextrin particles. The particle structure of these samples resembles crystals with various sizes, which is typical for lactose [31] and trehalose [32].  
Table 1 shows the average particle sizes and amylograph properties of used carbohydrates. The smallest D (4,3) and D (3,2) diameters were observed for rice starch (6.4 and 5.2 \(\upmu\)m), respectively. Wheat and maize starches were characterized by about three times higher mean diameters compared to rice starch. The largest mean diameters, both D (4,3) and D (3,2), were determined for trehalose. [PERSON] et al. [27] and [PERSON] et al. [30] also reported that rice starch granules are the smallest among starches of cereal grains.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Parameter** & **Maltodextrin** & **Wheat Starch** & **Rice Starch** & **Maize Starch** & **Lactose** & **Trehalose** \\  & **(DE = 17.5)** & & & & & \\ \hline D (4,3) (\(\upmu\)m) & 69.2 (0.23) d & 27.4 (2.77) c & 6.4 (0.07) a & 16.7 (0.00) b & 107.5 (7.00) e & 231.7 (1.50) f \\ D (3,2) (\(\upmu\)m) & 51.7 (0.53) d & 13.2 (1.42) b & 5.2 (0.31) a & 15.0 (0.10) b & 36.6 (3.58) c & 87.2 (3.59) e \\ Maximal paste & - & 150 (0.20) c & 1210 (8.63) a & 520 (2.11) b & - & - \\ viscosity (BU) & - & 84 (0.01) a & 66 (0.02) c & 78 (0.00) b & - & - \\ Initial gelatinization & - & 93 (0.11) a & 88 (0.32) b & 93 (0.18) a & - & - \\ \hline \end{tabular} a,b,c,... --average values in lines with different letters are significantly different (\(p\leq 0.05\)).  
\end{table}
Table 1: Mean diameters and amylograph properties of used carbohydrate materials.  
One of the most important functional characteristics of starch is its gelatinization properties. There are specific temperature ranges for gelatinization corresponding to each type of starch. In our study, the highest initial gelatinization temperature was determined for wheat starch (84 \({}^{\circ}\)C), while the lowest for rice starch (66 \({}^{\circ}\)C). Additionally, rice starch had a lower final gelatinization temperature (88 \({}^{\circ}\)C) compared to wheat and maize starches (93 \({}^{\circ}\)C). Rice starch had the highest amylograph viscosity (1210 BU) compared to maize (520 BU) and wheat starch (150 BU). Observed phenomenon is due to natural differences in molecular structure of starch from different sources [33], but low viscosity of gelatinized wheat starch indicates the high depolymerization of amylose and amylopectin, probably processed by native \(\alpha\)-amylase [34] during wheat plant growing, grain storage or starch isolation. Such hydrolys starch subunits can more effectively absorb hydrophobic moieties, as in this study, pumpkin oil [35; 36]. This shows that wheat starch should have the greatest pumpkin oil lipid-binding capacity.  
Figure 1: SEM images of used carbohydrate materials: maltodextrin (M), wheat starch (WS), rice starch (RS), maize starch (MS), lactose (L) and trehalose (T).