Fruits are an important source of nutrients such as carbohydrates, minerals, lipids, vitamins and fiber, they also have bioactive compounds including antioxidants. When these foods are consumed, the bark and the seed are generally discarded without being aware of the organic residue that is generated and the nutrients that are not used. The Santa Amelia variety watermelon is a fruit grown and consumed in Mexico; it contains essential nutrients that are beneficial to health. In the present study of dehydrated and pulverized watermelon peel, the content of phenols and flavonoids in methanolic extract was quantified, implementing the Folin Ciocalteu and aluminum trichloride methods, respectively. For the determination of its antioxidant activity, two methods were carried out; DPPH method (2,2-diphenyl-1-picryl hydrazyl) and ABTS (2,2-azino-bis 3 ethylbenzothiazolin-6-sulfonic acid-2NH4), in addition to its physicochemical characterization. The results obtained in phenols were 0.90±0.03 mg EAG/g of dry sample and in flavonoids 4.51±0.10 mg EQ/g of dry sample, with an antioxidant activity for the DPPH method of 17.14% and for ABTS of 121.69%, the latter being the most active. Dilutions were made with pure extract, dilution 1:1, 1:5, 1:10). Within the proximal analysis, the following results were obtained: carbohydrates 61.498%, ashes 13.23%, crude fiber 8.21%, protein 7.17%, moisture 7.03%, and ether extract 2.91%.
Las frutas son fuente importante de nutrientes como carbohidratos, minerales, lípidos, vitaminas y fibra, además presentan compuestos bioactivos entre ellos los antioxidantes. Cuando se consumen estos alimentos generalmente la corteza y la semilla se desechan sin ser conscientes del residuo orgánico que se genera y de los nutrientes que no se aprovechan. La sandía variedad Santa amelia es una fruta cultivada y consumida en México, contiene nutrientes esenciales que son beneficiosos para la salud. En el presente estudio de cáscara de sandía deshidratada y pulverizada se cuantificó el contenido de fenoles y flavonoides en extracto metanólico, implementando los métodos Folin Ciocalteu y tricloruro de aluminio respectivamente. Para la determinación de su actividad antioxidante se realizaron dos métodos; método de DPPH (2,2-difenil-1-picril hidrazilo) y ABTS (Ácido 2,2-azino-bis 3 etilbenzotiazolin-6-sulfónico ácido-2NH4), además de la caracterización fisicoquímica de la misma. Los resultados obtenidos en fenoles fueron de 0.90±0.03 mg EAG/g de muestra seca y en flavonoides de 4.51±0.10 mg EQ/g de muestra seca, con una actividad antioxidante para el método del DPPH de 17.14% y para ABTS de 121.69%, siendo este último con mayor actividad. Se realizaron diluciones con extracto puro, dilución 1:1, 1:5, 1:10). Dentro del análisis proximal se obtuvieron los siguientes resultados: carbohidratos 61.498%, cenizas 13.23%, fibra cruda 8.21%, proteína 7.17%, humedad 7.03%, y extracto etéreo 2.91%.
