PHENOLIC COMPOUNDS AND ANTIOXIDANT ACTIVITY IN LEAVES OF THREE AMARANTH SPECIES AS EFFECT OF CULTIVATION LOCATION AND FERTILIZATION/COMPUESTOS FENOLICOS Y ACTIVIDAD ANTIOXIDANTE EN HOJAS DE TRES ESPECIES DE AMARANTO COMO EFECTO DE LOCALIDAD DE CULTIVO Y FERTILIZACION/COMPOSTOS FENOLICOS E ATIVIDADE ANTIOXIDANTE EM FOLHAS DE TRES ESPECIES DE AMARANTO COMO EFEITO DO LOCAL DE CULTIVO E DA FERTILIZACAO

The objective was to evaluate the effect of crop location, fertilization, species and genotypes on the content of flavonoids and total polyphenols and on antioxidant activity in the leaves and sprouts of amaranth. Sowing and cultivation were carried out in Huaquechula, Puebla, and Tepetitla, Tlaxcala, Mexico under a factorial arrangement of 16 genotypes of Amaranthus hypochondriacus L. (2), A. hybridus L. (8) and A. cruentus L. (6) and two fertilization conditions (with and without 18N-07P-09K) under a randomized block design with two repetitions. At 40 days after planting, a sample of leaves and sprouts was collected, dried at room temperature and ground; later, the flavonoids, total polyphenols and antioxidant activity (methods DPPH and FRAP) were quantified by UV-visible spectrophotometry and reference standards. The results showed that crop location, use or nonuse of fertilizer, species and genotype had a significant effect on flavonoids, total polyphenols and antioxidant activity. Huaquechula had days with low precipitation and high temperatures; such environmental conditions influenced the content of flavonoids and total polyphenols and antioxidant activity. A. hybridus showed high flavonoid and total polyphenol values that were significantly different from the values recorded for A. hypochondriacus and A. cruentus.