# Nutritional and Functional Properties of Gluten-Free Flours
## 3 Results
### Fatty Acid Profile  
The most abundant fatty acids were oleic, linoleic, and palmitic acid (Figure 1a), while stearic and \(\alpha\)-linolenic acid were in lower amounts (<8% of the total fat) (Figure 1b). The content of palmitic acid in plantain flour (34.9%) was significantly higher (\(p<0.05\)) compared to the other GF sources. In addition, the content of stearic acid was significantly higher (\(p<0.05\)) for plantain and tiger nut flours.  
Figure 1: _Cont_.  
Tiger nut flour had the highest oleic acid content (67%), whereas the lowest was in the chickpea sample (20.4%) (\(p<0.05\)). Gram, \(\alpha\)at, and rice flours did not reveal significant differences in oleic acid content (\(p>0.05\)); the values were around 40% (Figure 1a).  
In contrast with the highest content in the oleic acid, tiger nut flour showed the lowest level in linoleic acid (10.2%) and \(\alpha\)-linolenic acid (0.2%). Thus, tiger nut flour was the highest in MUFA and lowest in PUFA (\(p<0.05\)) (Figure 1c). It was stated that tiger nut oil has a MUFA profile similar to olive oil [49]. Moreover, it was reported that tiger nut  
Figure 1: Fatty acid composition of investigated gluten-free flours: (**a**) palmitic acid, oleic acid, and linoleic acid; (**b**) stearic acid and \(\alpha\)-linolenic acid; (**c**) Proportions of fatty acid groups (% of total fatty acids) of GF flours. The data are presented as mean values \(\pm\) standard deviation (n = 3). Bars with different superscripted letters indicate significant differences (\(p<0.05\)). SFA: saturated fatty acid; MUFA: monounsaturated fatty acid.  
oil reduced low-density lipoprotein cholesterol and increased high-density lipoprotein cholesterol as well as stimulated the absorption of calcium in bones mainly attributed to the short and medium chain fatty acids, oleic acid, and essential fatty acids [50].  
Teff flour showed a high amount of \(\alpha\)-linolenic acid (7.9%; \(p<0.05\)), followed by quinoa flour (7.1%). The high value found in teff flour is in line with a recent study [51], which stated also that \(\alpha\)-linolenic acid level in teff was higher than other cereals: sorghum, millet, wheat rice, maize, or oat.  
Summing up, the range for the two essential fatty acids varied as following: millet > chickpea > maize > quinoa > amaranth > teff > gram > brown rice > oat > buckwheat > rice > plantain > tiger nut (for linoleic acid) and teff > quinoa > buckwheat > brown rice \(\approx\) chickpea > maize > gram \(\approx\) rice > oat > amaranth \(\approx\) plantain > tiger nut (for \(\alpha\)-linolenic acid).  
Comparing PUFA/SFA, the most favorable ratio was for chickpea (4.7) and quinoa (4.5), followed by millet and maize (3.9), gram (3.2), and teff (3.1) flours. The others flours had lower values (<2). The higher PUFA/SFA ratio, the more positive effect on cardiovascular health [52]. Regarding the ratio between omega 6 to omega 3, the values for millet (74.3), tiger nut (61.4), and amaranth (49) flours were higher than for the other GF sources analyzed i.e., chickpea, plantain, gram and maize flours with ratio in the range of 23.6 to 28.3 and rice, quinoa, buckwheat, and brown rice flours with the lowest ratios (6.1-14.5).  
A recent study investigating the fatty acid profile of gluten-free bakery products showed that MUFA represent the majority fatty acid group, followed by SFA (30%) and PUFA (13%) [53]. Another study involving celiac children from Sweden remarked a high intake of SFA and low intake of PUFA in their diet [54].  
The values of fatty acid composition were calculated also to g/100 g d.m. flour and are presented in Table S2.