Correlation between water stress and phenolic compounds of hydroSOStainable almonds

Water scarcity is currently affecting many areas of the world, reaching worrying levels in drought areas such as southern Spain. To cope with this issue, researchers in the agricultural sector have implemented deficit irrigation strategies intended to reduce water consumption by increasing fruit quality. Almond is among the most popular tree nuts worldwide and also the most nut cultivated in Spain. Almond consumption, together with other nuts, has been widely associated with improvements in cardiovascular health, metabolic syndrome and diabetes owing to their bioactive compounds such as polyphenols. Water deficit strategies generate hydroSOStainable almonds, raised under water stress conditions, with high content of bioactive compounds. The aim of this work was to study the relationship between water stress, color and polyphenols in hydroSOStainable almonds. For this, instrumental color, total phenolic content and phenolic compounds were measured and correlated using Pearson's correlation.

The results showed a strong relationship between water stress, color and polyphenols of almonds, showing that increasing water stress in plants up to ~100 MPa × day values of stress integral increase the polyphenols in almonds, leading to a reddish color.

Finally, this research demonstrated that implementing water-saving strategies help to improve the phenolic content and color of hydroSOStainable almonds and also that isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside and kaempferol-3-O-glucoside could be important markers of hydroSOStainable almonds (cv. Vairo). Besides, hydroSOStainable almonds could be an important source of phenols, providing 25% of the estimated total polyphenolic daily intake. © 2020 Society of Chemical Industry.