# Physical and Functional Characteristics of Extrudates Prepared from Quinoa Enriched with Goji Berry
## 3 Results and Discussion
### Expansion Ratio  
ER and BD are determined to directly classify the expanded extrudate characteristics. Extruded products desirable to consumers have a well puffing. The most desired characteristics for expanded products are high expansion and low density [15]. The quinoa has lower expansion ratio values [15; 17] compared to other materials, which may be explained by fact that the quinoa flour had higher amounts of protein, fiber, and lipids in comparison to other cereal grains. The Pareto charts (Figure 1) showed that all effects were significant for the expansion ratio, and both investigated variables influenced approximately equally and negatively on the expansion. The decrease in the moisture resulted in a decrease in the degree of starch gelatinization, which limited the expansion [27]. Under the extrusion of the raw material with higher moisture, it could not evaporate sufficient water, which resulted in products with a higher BD [28]. The authors of [20] established that the addition of 3 and 7% of goji berries in rice semolina led to an increase in the ER, whereas higher addition levels led to a significant decrease in the ER. In our study, a similar maximum was not observed. The effect of two investigated variables on the expansion ratio of extrudates is shown in Figure 2. The figure shows that the expansion decreased by approximately 10% at a low amount of goji berries with an increase in the moisture content. At the high level of the goji berries' amount, the expansion ratio remained constant with the increase in the moisture content. The effect of the goji berries' amount was clearly expressed at a low level of moisture content and was approximately imperceptible at a high level of moisture. The expansion depended on the feed moisture, and this would affect the viscoelastic characteristics of the starch-based material. The level of feed moisture content during extrusion provoked changes in the amylopectin molecular structure of the material, reducing the melt elasticity and decreasing the expansion of the extruded product [27]. The authors of [29] reported that low feed moisture content may limit the flow of the material and increase the shearing rate and residence time, leading to an increase in the level of gelatinization and expansion.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**J0** & **ER** & **BD, g/cm\({}^{3}\)** & **WAL, g/g** & **WSI, \%** & **HD, N** & **SME, Wh/kg** \\ \hline
1 & \(2.15\pm 0.05\) \({}^{a}\) & \(0.146\pm 0.004\) & \(8.05\pm 0.06\) \({}^{a}\) & \(21.78\pm 0.27\) \({}^{a}\) & \(24.21\pm 0.94\) \({}^{a}\) & \(71.08\pm 1.99\) \({}^{a}\) \\
2 & \(1.93\pm 0.06\) \({}^{b}\) & \(0.170\pm 0.004\) & \(7.51\pm 0.12\) \({}^{b}\) & \(25.61\pm 0.53\) \({}^{b}\) & \(17.24\pm 1.33\) \({}^{b}\) & \(81.12\pm 2.01\) \({}^{b}\) \\
3 & \(1.93\pm 0.03\) \({}^{b}\) & \(0.195\pm 0.004\) & \(6.53\pm 0.14\) \({}^{c}\) & \(20.68\pm 0.39\) \({}^{c}\) & \(29.93\pm 0.32\) \({}^{c}\) & \(36.19\pm 1.36\) \({}^{c}\) \\
4 & \(1.93\pm 0.01\) \({}^{b}\) & \(0.268\pm 0.012\) & \(6.34\pm 0.12\) \({}^{c}\) & \(19.46\pm 0.22\) \({}^{d}\) & \(23.09\pm 1.02\) \({}^{a}\) & \(55.44\pm 2.22\) \({}^{d}\) \\
5 & \(2.02\pm 0.02\) \({}^{c}\) & \(0.205\pm 0.010\) & \(7.07\pm 0.03\) \({}^{d}\) & \(22.42\pm 0.26\) \({}^{a}\) & \(19.60\pm 0.51\) \({}^{d}\) & \(54.67\pm 2.28\) \({}^{d}\) \\
6 & \(2.08\pm 0.05\) \({}^{c}\) & \(0.156\pm 0.006\) & \(7.07\pm 0.01\) \({}^{d}\) & \(21.98\pm 0.13\) \({}^{m}\) & \(21.44\pm 0.51\) \({}^{e}\) & \(54.32\pm 2.34\) \({}^{d}\) \\
7 & \(1.94\pm 0.05\) \({}^{b}\) & \(0.203\pm 0.006\) & \(7.02\pm 0.02\) \({}^{d}\) & \(21.97\pm 0.07\) \({}^{a}\) & \(18.20\pm 0.65\) \({}^{b}\) & \(58.21\pm 1.16\) \({}^{d}\) \\ \hline \end{tabular} Different lowercase letters (a, b, c, d, e) show a significant difference between the experimental runs (\(p<0.05\)).  
\end{table}
Table 2: Experimental results for physical and functional characteristics of extrudates.