Estudio de la capacidad antioxidante del arazá (Eugenia stipitata Mc Vaugh) durante la maduración

Research of antioxidant capacity of araza (Eugenia stipitata Mc Vaugh) during the ripening

El arazá es un fruto amazónico con buena capacidad antioxidante. En este trabajo se realizó, a partir del epicarpio y mesocarpio de la fruta en cuatro estados de madurez (verde, pintón, maduro y sobremaduro), la extracción de compuestos fenólicos (utilizando como solvente una mezcla de agua:acetona, ( inicial 50:50 y posterior de 70:30)) y su análisis (método colorimétrico de Folin-Ciocalteu), y se identificaron parcialmente por HPLC en fase reversa, con arreglo de diodos, encontrando  los ácidos clorogénico, gálico y caféico   como  fenoles mayoritarios  responsables de la actividad antioxidante. El contenido de polifenoles en el mesocarpio  es mayor en el estado verde (1200mg/1000g fruto BH) seguido del  maduro (1100mg/1000g fruto BH), pintón (905 mg/1000g fruto BH) y sobremaduro (550mg/1000g fruto BH), mientras que en el epicarpio es mayor en  estados maduro (170 mg/1000g fruto BH) y verde (295mg/1000g fruto BH) seguidos del pintón (100 mg/1000g fruto BH) y sobremaduro (50 mg/1000g fruto BH). La capacidad antioxidante fue determinada por  métodos hidrofílicos (ABTS, DPPH y FRAP) encontrando que en el mesocarpio la capacidad antioxidante medida por todos los métodos  es mayor en  estado verde seguido del  maduro, pintón y sobremaduro mientras en el epicarpio es mayor en  maduro y verde seguido del pintón y sobremaduro. Se determinó la capacidad antioxidante por un método lipofílico (decoloración del β-caroteno) encontrando que en el mesocarpio es mayor en estados maduro (110 mg/1000g fruto BH) y pintón (90 mg/1000g fruto BH) seguido del sobremaduro ( 75mg/1000g fruto BH) y verde (26mg/1000g fruto BH) y en el epicarpio es mayor en sobremaduro (50 mg/1000g fruto BH) seguido del verde (45 mg/1000g fruto BH), maduro (55 mg/1000g fruto BH) y pintón (25 mg/1000g fruto BH). Finalmente se concluye que el fruto de arazá en los estados verde y maduro presenta la mayor capacidad antioxidante, siendo los ácidos  fenólicos los principales contribuyentes.

The araza is a fruit native of the Amazon region, like other fruits of this region has some antioxidant components. This work was carried out the classification of the fruits of araza in four different states using as the index of maturity, then phenolic compounds were extracted using mixtures of solvents (methanol, acetone, water) and your content was determined by the spectrophotometric method Folin-Ciocalteu in the epicarp and mesocarp. Additionally, partially identified phenolic compounds by reversed phase HPLC with diode array, finding the phenolic acids such as chlorogenic, gallic and caffeic, such as phenols responsible for the majority of araza antioxidant activity. It was noted that araza mesocarp polyphenol content was higher in the green (1200 mg/1000g fruto BH) state followed by mature (1200 mg/1000g fruto BH), pinton (905 mg/1000g fruto BH) and over mature (550 mg/1000g fruto BH) while the epicarp was greater in states mature (170 mg/1000g fruto BH) and green (295 mg/1000g fruto BH) followed of the over-mature (50 mg/1000g fruto BH) and pinton (100 mg/1000g fruto BH) states. The antioxidant capacity was determined by three hydrophilic methods (ABTS, DPPH and FRAP) in the mesocarp found that the antioxidant capacity was higher in the green state followed by mature), pinton  and over mature while the epicarp was higher in mature, green, pinton) and over-mature state. We also determined the antioxidant capacity by a lipophilic method (b-carotene bleaching) found that in the mesocarp was higher in states followed by mature (110 mg/1000g fruto BH), pinton (90 mg/1000g fruto BH) and  green (26 mg/1000g fruto BH) while in the epicarp was higher in the over mature stage (50 mg/1000g fruto BH)followed by greeen states (45 mg/1000g fruto BH), mature (55 mg/1000g fruto BH)and  sobre mature  (25 mg/1000g fruto BH). Finally we conclude that the mature and green had the highest antioxidant capacity, phenolic compounds being present in the epicarp and mesocarp were the major contributors.