# Usefulness of Rowanberry for Improving the Nutritional Value of Buckwheat Flour Extrudates
## 3 Results and Discussion
### Texture Profile  
The texture is of primary significance for extrudates foods. The major ingredient which determines the texture of these products is flour. In addition, many components affect the general texture of these products [1]. The texture results of extruded samples prepared with corn-buckwheat in different percentages can be seen in Figure 6. According to the results, it was determined that the control and milk-added extrudates had the highest hardness. In unexpanded products containing milk, a decrease was observed in the hardness values of the samples as the buckwheat flour ratio increased. Moreover, an inverse correlation  
Figure 5: The expansion ratio of extruded samples at 30% and 40% buckwheat ratios. **E** Expanded; **30W**: 30% Buckwheat + 30% Corn grits + Water; **30M**: 30% Buckwheat + 30% Corn grits + Milk; **30 WR**: 30% Buckwheat + 30% Corn grits + Water + Rowanberry; **30 MR**: 30% Buckwheat + 30% Corn grits + Milk + Rowanberry; **40W**: 40% Buckwheat + 40% Corn grits + Water; **40M**: 40% Buckwheat + 40% Corn grits + Milk + Rowanberry; **40 WR**: 40% Buckwheat + 40% Corn grits + Water + Rowanberry. was obtained in the hardness of the samples after expansion. Expanded products showed an average of 50% less hardness than their unexpanded equivalent. The results were also confirmed by [PERSON]'s and [PERSON]'s tests at the significance level of \(\alpha\)= 0.05. The usefulness of buckwheat in reducing hardness and other textural features is also demonstrated by [PERSON] et al. [57]. However, the results obtained in the work are burdened with a high standard deviation caused by the lack of a uniform shape of the extrudates. In contrast, the hardness values of the extruded products prepared using various ratios (70:30, 50:50, 30:70 corn-buckwheat) of corn flour and buckwheat flour increased in parallel with the rise in the buckwheat flour ratio. As the protein (average 12.94%) and fat (about 3%) content of buckwheat are much higher than the protein (6.79%) and fat (0.07%) contents of corn, the differences in hardness can be attributed to these components [10; 37]. In addition, the carbohydrate (38.42%), protein (26.32%), and fat (26.71%) contents of milk affected the hardness value of the samples. The high sugar content of the milk powder may have increased firmness by causing the samples to increase in density and decrease in cell size [20]. In addition, the extrusion processing conditions can also show an effect on the hardness of the final product [29]. [PERSON] et al. [29] reported that the lowest hardness for the extruded samples was at low moisture and high temperature. As seen in Figure 6, in the group of products before processing, it was established that the addition of rowanberry caused a decrease in the hardness of the samples by approximately 50%. However, adding milk with rowanberry did not significantly change the hardness. In the case of expanded products, the highest hardness was found for the sample containing 50% buckwheat flour with milk, followed by 30% buckwheat flour with water. It was observed that adding milk or rowanberry had no significant effect on hardness. The hardness of the extrudates is also related to the expansion ratio of the product [54]. The increase in air bubbles in the product leads to a rise in ambient pressure, destroying the cell walls and releasing the water vapour to expand the product and reduce its hardness [58]. Thus, the decrease in hardness of rowanberry-added samples compared to the control can be associated with the increase in the expansion volume. Many researchers have investigated the effect on the texture of the used supplements, except for rowanberry in the extruded samples. It was reported that adding rosehip (_Rosa canina_) powder (10%) to corn extrudate reduced hardness compared to the control sample. In the present study, the hardness results compared to the control are lower than those reported by previous researchers.