# Nutritional and Functional Properties of Gluten-Free Flours
## 3 Results
### Protein Digestibility  
Figure 2 shows the values of the in vitro protein digestibility of the GF flours. Protein digestibility refers to the ability of the protein to be enzymatically hydrolyzed into amino acids. Amaranth flour had the highest digestibility (78.7%; \(p<0.05\)) among all the flours studied. Tiger nut samples with the lowest protein and highest fiber content had the lowest  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Flours**} & \multicolumn{8}{c}{**AAS**} & \multicolumn{2}{c}{**PDCAAS**} \\ \cline{2-9}  & **His** & **Ileucine** & **Leu** & **Lys** & **Cys + Met** & **Phe + Tyr** & **Val** \\ \hline Rice & 1.52 & 1.04 & 1.37 & 0.73 & 1.59 & 2.54 & 1.41 & 0.56 \\ Brown rice & 2.09 & 1.49 & 1.43 & 0.84 & 1.49 & 2.31 & 1.58 & 0.61 \\ Maize & 2.08 & 1.24 & 2.09 & 0.65 & 1.86 & 2.26 & 1.27 & 0.47 \\ Oat & 1.40 & 1.59 & 1.52 & 1.17 & 2.49 & 2.59 & 1.60 & 0.89 \\ Millet & 1.35 & 1.22 & 2.00 & 0.38 & 2.33 & 2.39 & 1.28 & 0.27 \\ Teff & 1.49 & 1.02 & 1.33 & 0.66 & 2.33 & 2.20 & 1.19 & 0.49 \\ Amaranth & 1.52 & 0.94 & 0.96 & 1.17 & 2.08 & 1.76 & 0.89 & 0.70 \\ Buckwheat & 1.45 & 1.10 & 1.07 & 1.32 & 1.71 & 1.86 & 1.22 & 0.78 \\ Quinoa & 1.79 & 1.13 & 1.15 & 1.19 & 1.57 & 1.77 & 1.18 & 0.85 \\ Chickpea & 2.15 & 1.69 & 1.64 & 1.88 & 1.62 & 2.74 & 1.37 & 0.97 \\ Gram & 1.70 & 1.28 & 1.28 & 1.48 & 1.32 & 2.13 & 1.08 & 0.78 \\ Tiger nut & 1.40 & 0.77 & 0.89 & 1.01 & 1.26 & 1.06 & 1.05 & 0.54 \\ Plantain & 2.01 & 1.08 & 1.00 & 0.86 & 1.12 & 1.62 & 1.09 & 0.62 \\ \hline \hline \end{tabular} Values AAS were calculated based on the recommendation of amino acid requirements for daily adult intake [23], Highlighted values represent the limiting value of AAS. When AAS \(<1\), the corresponding amino acid is considered a limiting one.  
\end{table}
Table 4: Amino acid scores (AAS) and protein digestibility corrected amino acid score (PDCAAS) of GF flours.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Flours** & **Protein Score, \%** & **AAAI** & **BV** & **PER** & **NI** \\ \hline Rice & 47.24 & 74.93 & 69.97 & 35.88 & 6.11 \\ Brown rice & 54.24 & 83.20 & 78.98 & 38.03 & 7.33 \\ Maize & 41.50 & 83.26 & 79.06 & 57.03 & 6.04 \\ Oat & 75.19 & 91.36 & 87.88 & 36.68 & 9.62 \\ Millet & 24.59 & 74.23 & 69.22 & 52.32 & 7.41 \\ Teff & 42.30 & 74.73 & 69.75 & 31.43 & 8.89 \\ Amaranth & 52.32 & 69.33 & 63.87 & 20.93 & 11.15 \\ Buckwheat & 61.27 & 74.69 & 69.71 & 25.76 & 11.14 \\ Quinoa & 60.73 & 75.59 & 70.70 & 28.83 & 10.13 \\ Chickpea & 62.62 & 99.97 & 97.27 & 44.01 & 18.59 \\ Gram & 51.07 & 78.29 & 73.64 & 33.99 & 18.59 \\ Tiger nut & 42.80 & 59.45 & 53.10 & 22.08 & 2.76 \\ Plantain & 43.42 & 68.23 & 62.67 & 26.15 & 1.99 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Other nutritional indexes of GF flours.  
protein digestibility (70.4%). A previous report stated that lower digestibility is correlated with increasing contents of fiber [58]. Plantain, brown rice, maize, and gram are a good source of protein as their protein digestibility (72.3-72.5%) were higher than chickpea, millet, and tiger nut (70.4-71.4%). In general, variations in protein digestibility take place after baking and [PERSON] [59] showed that the baking process resulted in significant improvement in protein digestion of spelt bread.