# Effect of Plant Biostimulants on Nutritional and Chemical Profiles of Almond and Hazelnut
## 3 Results and Discussion
### Tocoplerols  
As in most foods with high fat content, the concentration of tocopherols (Table 3) was elevated: average values of 50 mg/100 g fw in almonds and 25 mg/100 g fw in hazelnuts, which is in agreement with previous reports [45; 46]. Considering the concentration in total tocopherols, the soil supplementation with phytoalgae produced an increase around 10% (50 to 55 mg/100 g fw), mainly due to the increase in \(\alpha\)-tocopherol and \(\gamma\)-tocopherol. Nonetheless, all other assayed biostimulants had an opposite effect.  
In what concerns hazelnuts, all biostimulants had the capacity to increase the tocopherols content, with the mixture NPK + phytoalgae as the one reaching the best results (23 to 28 mg/100 g fw). This is a positive result, although not entirely surprising. The European Biostimulant Industry Council (www.biostimulants.eu (accessed on 19 December 2020)) defined \"plant biostimulants as containing substance(s) and/or micro-organisms whose function when applied to plants or the rhizosphere is to stimulate natural processes to enhance/benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, and crop quality\". These improvements are mainly based in mechanisms able to enhance key physiological, biochemical and molecular processes. Besides, their effects in nutrients availability, using biostimulants has been related to the up-regulation of photosynthesis and improved nitrogen and carbon metabolism, which can result in higher expressions of antioxidant compounds such as tocopherol [47].  
The obtained values were lower than those reported in different hazelnut varieties [48], which might be related with genetic factors (different cultivars), climatic variation [49; 50], soil type [41], or analytical methodology [42].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Biostimulant** & **C16:0** & **C18:0** & **C18:1n9c** & **C18:2n6c** \\ \hline \multicolumn{5}{c}{Almond (Vairo cultivar)} \\ \hline Control & 8.8 \(\pm\) 0.5 a  & 2.0 \(\pm\) 0.1 b  & 71 \(\pm\) 0.6 b  & 17.2 \(\pm\) 0.5 a  \\ Phytoalgae & 8.7 \(\pm\) 0.5 a  & 2.0 \(\pm\) 0.1 b  & 71 \(\pm\) 0.9 ab  & 16.9 \(\pm\) 0.3 b  \\ Tradebor® & 8.1 \(\pm\) 0.5 b  & 2.1 \(\pm\) 0.1 a  & 72 \(\pm\) 0.8 a  & 17.1 \(\pm\) 0.4 ab  \\ Sprint Plus® & 8.8 \(\pm\) 0.3 a  & 2.0 \(\pm\) 0.1 b  & 71 \(\pm\) 1.0 b  & 17.2 \(\pm\) 0.5 a  \\ NeoMor® & 9.1 \(\pm\) 0.5 a  & 1.9 \(\pm\) 0.1 b  & 71 \(\pm\) 0.8 b  & 17.2 \(\pm\) 0.1 a  \\ \hline ANOVA \(p\)-value (n = 45) & \textless{}0.001 & \textless{}0.001 & 0.002 & 0.001 \\ \hline \multicolumn{5}{c}{Hazelnut (Ennis cultivar)} \\ \hline Control & 8.8 \(\pm\) 0.3 d  & 2.5 \(\pm\) 0.1 b  & 76 \(\pm\) 1.0 a  & 11.7 \(\pm\) 0.3 d  \\ NPK & 9.1 \(\pm\) 0.4 cd  & 2.1 \(\pm\) 0.1 d  & 72 \(\pm\) 2.0 de  & 15.1 \(\pm\) 0.5 a  \\ NPK + phytoalgae & 8.9 \(\pm\) 0.3 cd  & 2.3 \(\pm\) 0.1 c  & 73 \(\pm\) 1.0 c  & 14.3 \(\pm\) 0.4 b  \\ Sprint Plus® & 9.6 \(\pm\) 0.4 a  & 2.8 \(\pm\) 0.1 a  & 72 \(\pm\) 1.1 e  & 14.5 \(\pm\) 0.4 b  \\ NPK + Sprint Plus® & 9.5 \(\pm\) 0.5 ab  & 2.1 \(\pm\) 0.1 d  & 73 \(\pm\) 1.0 cd [FONOTE:d]Footnote e: footnotemark: [ENDFOOTNOTE] & 14.3 \(\pm\) 0.3 b  \\ Phytoalgae & 9.2 \(\pm\) 0.5 bc  & 2.4 \(\pm\) 0.2 b  & 74 \(\pm\) 1.0 b  & 12.7 \(\pm\) 0.3 c  \\ \hline ANOVA \(p\)-value (n = 54) & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 \\ \hline \hline \end{tabular}  
* If \(p<0.050\), the corresponding parameter presented a significantly different value for at least one biostimulant; different letters indicate significantly different values. Results are presented as mean \(\pm\) standard deviation.  
\end{table}
Table 2: Major fatty acids profile (relative%) for almond and hazelnut cultivars submitted to different plant biostimulant treatments.