## 3 Results
### Assessment of the Nutritional Profile and Physico-Chemical Properties
The bands in the region of 1740 cm\({}^{-1}\) and 2830-3010 cm\({}^{-1}\) are associated with the lipids from the sample composition. The peak intensity from 1744 cm\({}^{-1}\) for the almond powder sample, compared to the other samples, is in correlation with the results obtained for the total fats analysis, which reveals that almond powder has the highest lipid content out of the tested samples (6.91%) (Table 1). The N-H stretching vibration gives rise to the amide A band between 3130 cm\({}^{-1}\) and 3400 cm\({}^{-1}\). Its frequency depends on the strength of the hydrogen bond. The amide A band is usually part of a Fermi resonance doublet with the second component absorbing weakly between 3010 cm\({}^{-1}\) and 3100 cm\({}^{-1}\) (amide B). The protein content obtained by the Bradford assay was comparatively lower than that obtained using the Kjeldahl method for all the samples (Tables 1 and 3), the main cause being that only the total nitrogen content was measured through Kjeldahl, whereas other biomolecules containing nitrogen, such as amino acids, nucleic acids and other nitrogenous compounds [60] or insoluble proteins may have been present. Among the products tested, the highest soluble protein content was obtained for almond powder while yeast powder had the lowest content, probably due to its nucleic acid content. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **Amide A** & **Amide B** & **Amide I** & **Amide II** & **Amide III** & **Lipid** \\  & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** & **(cm\({}^{-1}\))** \\ \hline Yeast powder & 3277 & 3010–3060 & 1625 & 1525 & 1180–1430 & 1733 \\  & & & & & 2835–2990 \\ \hline _Pleurotus_ spp. flour & 3207 & 3020–3230 & 1631 & 1571 & 1185–1430 & 1710 \\  & & & & & 2800–2945 \\ \hline Pea powder & 3265 & 3010–3115 & 1626 & 1522 & 1185–1425 & 1740 \\  & & & & & 2830–3000 \\ \hline Almond powder & 3279 & 3020–3100 & 1636 & 1533 & 1200–1475 & 1744 \\  & & & & & 2800–3020 \\ \hline Spirulina powder & 3281 & 3010–3112 & 1638 & 1533 & 1185–1480 & 1734 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Wavenumbers assignment to the characteristic bands. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **Total Soluble** & **Total Free** & **Total Phenols** & **Total** & **DPPH (mM** & **FRAP (mM** \\  & **Proteins (mg/g)** & **(mg GAE/g)** & **(mg QE/g)** & **(mg QE/g)** & **TEAC/g)** & **TEAC/g)** \\ \hline Yeast powder & 2.91 \(\pm\) 0.16 d & 13.00 \(\pm\) 0.24 b & 0.88 \(\pm\) 0.04 a & 0.60 \(\pm\) 0.12 e & 2.16 \(\pm\) 0.69 d & 0.82 \(\pm\) 0.04 d \\ \hline _Pleurotus_ spp. flour & 6.15 \(\pm\) 0.55 cd & 42.25 \(\pm\) 1.61 a & 6.51 \(\pm\) 0.09 b & 4.68 \(\pm\) 0.1 a & 5.48 \(\pm\) 0.29 c & 13.15 \(\pm\) 1.19 a \\ \hline Pea powder & 12.73 \(\pm\) 0.51 b & 6.31 \(\pm\) 0.05 cd & 1.25 \(\pm\) 0.02 c & 0.98 \(\pm\) 0.07 d & 1.04 \(\pm\) 0.17 e & 0.52 \(\pm\) 0.04 d \\ \hline Almonds powder & 95.25 \(\pm\) 4.69 a & 8.04 \(\pm\) 0.5 c & 3.90 \(\pm\) 0.15 d & 3.26 \(\pm\) 0.21 b & 6.56 \(\pm\) 0.37 b & 8.11 \(\pm\) 0.63 b \\ \hline Spirulina powder & 6.23 \(\pm\) 0.86 c & 6.55 \(\pm\) 0.43 cd & 5.83 \(\pm\) 0.43 d & 2.68 \(\pm\) 0.1 c & 10.2 \(\pm\) 0.13 a & 7.52 \(\pm\) 0.47 bc \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Evaluation of total soluble proteins, free amino acids, phenol and flavonoid content and their antioxidant activity. In this study, the antioxidant activity was measured through two independents assays: FRAP and DPPH. Table 3 shows that the _Pleurotus_ spp. flour had strong antioxidant activity through the FRAP method and was correlated with the capacity of total free amino acids (chelation metals) and in a low manner with the phenol content and flavonoids. For almond powder, where a higher content of soluble proteins was obtained, the antioxidant activity was low through both methods. For spirulina powder, the antioxidant activity could be given by c-phycocyanins [61].