The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); to the
national funding by FCT, P.I., through the institutional scientific employment program-contract for
L. Barros and individual scientific employment program-contract (CEECIND/04479/2017). Further
acknowledgments are due to the European Regional Development Fund (ERDF) through the
Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-
FEDER-024479: ValorNatural®, whom the author F.S. Reis thanks for her contract. This work
was also funded by FEDER-Interreg España-Portugal programme through the project TRANSCo-
LAB 0612_TRANS_CO_LAB_2_P, and integrated in the activities of the Operational Group EGIS–
Estratégias de Gestão Integrada do Solo e da Água em Espécies Produtoras de Frutos Secos, funded
by PT2020 and EAFRD (European Agricultural Fund for Rural Development).
The increasing interest in natural foods with functional effects demands progressively
higher production levels. Nonetheless, there is an orientation towards practicing more sustainable
agriculture, free from environmentally harmful pesticides and fertilizers. Plant biostimulants, a
class of bio-based agriculture products designed to improve crop development, represent a feasible
alternative to chemical fertilizers, or, at least, an effective way of reducing the employed quantities.
Herein, different types of plant biostimulants compatible with organic farming (Phytoalgae, Foliar B,
Amino Acids, Soil B, Fitoalgas Green® and Sprint Plus®) were tested in two of the most important
nut products worldwide: almonds and hazelnuts, which were tested for nutritional parameters, fatty
acids profiles and tocopherols contents. Overall, the most notorious effects in almond samples were
obtained with phytoalgae (seaweed Ascophyllum nodosum extracts), particularly reflected in the
upraising around 10% of
-tocopherol and -tocopherol contents. Likewise, hazelnuts treated with
NPK + phytoalgae were also characterized by an increase of almost 18% in tocopherols levels, while
treatment with NPK alone induced 15.1% higher percentage of linoleic acid.
