CUANTIFICACIÓN DE POLIFENOLES Y FLAVONOIDES EN EL ACEITE DE LAS NUECES DE DIFERENTES HUERTAS DE NOGAL

<p><strong>Background: </strong>The consumption of walnuts and their oil has been associated with reduced blood pressure and cardiovascular risk, due to their content of fatty acids, fiber, chemical elements, vitamins and bioactive compounds (phenols, flavonoids). <strong>Objective:</strong> To analyze how environmental and genetic factors, particularly the physical-chemical characteristics of soils, influence the variability of the content and composition of the bioactive compounds of walnut orchards (<em>Carya</em> <em>illinoinensis</em> [Wangenh.] K. Koch). The hypothesis was that the bioactive compounds present in the oils of walnuts from different orchards vary depending on the chemical characteristics from the soil in which these develop. <strong>Methodology:</strong> To elucidate the above, samples of walnuts and soil were collected from four orchards. Likewise, oil extraction was carried out to quantify the content of functional compounds. The soils were chemically characterized to determine the correlations between them. For the content of polyphenols and flavonoids, the Folin-Ciocalteu and aluminum chloride methods by UV spectrophotometry were used. Each orchard was considered as a treatment, using a completely randomized design, and the Tukey<sub>0.05</sub> test to compare means. Additionally, Pearson's linear correlation analysis was applied to determine the link between bioactive compounds of the oils and the characteristics of the soils. <strong>Results</strong>: Statistically different concentrations of polyphenols (P≤0.05) were recorded in the walnut oil, ranging from 64.11 to 124.95 mg EAG•100 mL<sup>-1 </sup>oil, while the CTF contents presented a range of 473.59 to 704.59. The chemical properties of OM, CEC, pH and EC of the soils from the four orchards ranged from 1.50 to 4.61, 14.25 to 29.94, 7.88 to 8.07 and 0.92 to 16.6, respectively. Positive correlations were recorded for CTP and CTF, and for both characteristics with respect to soil OM. <strong>Implications</strong>: The results highlight the need to associate the phytochemical quality of crops with the properties of the soils or substrates where they grow, to establish improvements during their development. <strong>Conclusion:</strong> The highest content of polyphenols was recorded in the Narro orchard, with 40-year-old established trees. Flavonoids ranged from 473.59 to 704.59 mg EAG•100 mL<sup>-1</sup> oil and the oil content in nuts ranged from 60.5 to 65.6 mL of oil•100 g<sup>-1</sup> sample. The polyphenol and flavonoid compounds showed a positive correlation, in turn these compounds registered a positive correlation with the organic matter content of the soils.<strong></strong></p>