## 3 Results and Discussion
### Flow Behaviour of the Dry Soup Powders  
In Table 2, the flow behaviour parameters of the reference soup powder and chickpea flour-containing soup powders are presented. The bulk density of the PG-O containing soup powder was the same as the REF soup powder. However, the NG-O and INS powders had a lower and higher apparent bulk density, respectively. Hence, when INS or NG-O flour would be used in the soup powder formulation, the product volume in the single-portion packages would slightly change, which could be noticed by the consumer. The flowability index (ffc) gives information on the flow behaviour of the dry powders, where a ffc value below 1 indicates that the powder does not flow, a ffc value between 1-2 indicates a very cohesive powder, between 2-4 a cohesive powder, between 4-10 easy-flowing powder, and a ffc value above 10 a free flowing powder [28]. No significant differences were found between the four soup powder formulations, although the powders with chickpea flours are categorised as cohesive samples whereas the reference powder as very cohesive samples. This indicates that addition of chickpea flour might slightly improve the flowability of the powders. The basic flow energy (BFE) is the energy needed to displace powder when forced to flow, for example during mixing [28]. The BFE of the REF powder and the PG-O powder did not significantly differ, whereas the NG-O and INS powders required less energy to be displaced. Therefore, the replacement of PS by chickpea flour could be advantageous. The specific energy (SE) gives information about the flow behaviour in a low stress environment (e.g., during filling) [28]. An indication about the cohesiveness of the powders can be obtained from the SE, where an SE value below 5 indicates low cohesion, an SE value between 5-10 moderate cohesion, and an SE value above 10 a high cohesion. The REF powder showed high cohesion, whereas all chickpea containing powders showed moderate cohesion values. The replacement of PS with chickpea flour thus decreased inter \begin{table}
\begin{tabular}{c c c c c} \hline  & **REF** & **NG-O** & **PG-O** & **INS** \\ \hline Bulk Density (g/mL) & 0.459 \(\pm\) 0.001 b & 0.423 \(\pm\) 0.014 c & 0.479 \(\pm\) 0.005 b & 0.505 \(\pm\) 0.004 a \\ Flowability index (-) & 1.72 \(\pm\) 0.09 a & 2.95 \(\pm\) 0.58 a & 2.08 \(\pm\) 0.31 a & 2.40 \(\pm\) 0.08 a \\ Basic flow energy (mJ) & 990.18 \(\pm\) 4.68 a & 763.32 \(\pm\) 1.00 b & 885.28 \(\pm\) 65.14 ab & 828.00 \(\pm\) 0.02 b \\ Specific energy (mJ/g) & 10.79 \(\pm\) 0.29 a & 6.07 \(\pm\) 0.11 c & 6.04 \(\pm\) 0.37 c & 9.06 \(\pm\) 0.11 b \\ Stability Index (-) & 1.17 \(\pm\) 0.23 a & 1.17 \(\pm\) 0.21 a & 0.95 \(\pm\) 0.04 a & 0.95 \(\pm\) 0.02 a \\ Flow Rate Index (-) & 1.18 \(\pm\) 0.02 a & 1.10 \(\pm\) 0.00 a & 1.05 \(\pm\) 0.02 a & 1.01 \(\pm\) 0.07 a \\ \hline \end{tabular}
\end{table} 
Table 2: Flow behaviour parameters for reference soup powder and soup powders containing non-gelatinised open cell chicken flour (NG-O), pre-gelatinised open cell chickpea flour (PG-O), and commercial pre gelatinised open cell chickpea flour (INS). Values within one row indicated by the same letter are not significantly different (\(\alpha\) = 0.05). particular interlocking and therefore could reduce the risk of blockages during filling [49]. For this reason, it could be beneficial to replace PS with chickpea flour. The stability index (SI) of the soup powders represents the stability of the powder to repeated flow [30]. A powder with an SI between 0.9 and 1.1 has a stable powder rheology. When the SI is lower than 0.9, the powder is unstable, potentially due to de-agglomerations. In contrast, when the SI is higher than 1.1, the powder is unstable as result of de-aeration, moisture uptake, or agglomeration segregation [30; 32]. There was no significant difference between the REF and chickpea-flour-containing powders. However, the PG-O and INS powders fell in the stable sample category, whereas the REF and NG-O powders were slightly unstable.