Estudio de polifenoles, taninos y métodos químicos para determinar la actividad antioxidante de la semilla de sacha inchi (Plukenetia volubilis L) / Study of polyphenols, tannins and chemical methods to determine antioxidant activity in seeds of sacha inchi (Plukenetia volubilis L)

Sacha inchi, es una euphorbiaceae conocida como maní del Inca. Se encuentra distribuida en el Perú, en San Martín, Huánuco, Amazonas, Madre de Dios y Loreto. Objetivo: determinar la actividad de los compuestos fenólicos de las semillas de sacha inchi y su rol en el color, conservación, sabor de los alimentos y bebidas. Material y Métodos: el presente estudio se realizó con semillas de sacha inchi colectadas en Tarapoto por el Instituto Nacional de Investigación y Extensión Agraria (INIA). En el Centro de Bioquímica y Nutrición de la Facultad de Medicina Humana de la USMP. La determinación de polifenoles totales según Aparicio et al. (1999), taninos totales descrito por Price y Butler (1977) y actividad antioxidante mediante el método ORAC descrito por Prior y Cao (2000). Además de la capacidad inhibición de peróxido de hidrógeno según Wettasinghe y Shahidi (1999).y su poder reductor según Srivastava et al. (2006). Se trabajó con el aceite y la torta, obteniándose de cada muestra extractos hidrofílicos y lipofílicos. Resultados: se encontró mayor contenido de polifenoles totales, taninos totales, mayor poder reductor, mayor capacidad de inhibir peróxido de hidrógeno y mayor capacidad antioxidante en el extracto hidrofílico de la torta. Conclusiones: el extracto hidrofílico de la torta de sacha inchi mostró mayor contenido de polifenoles totales y taninos con acción antioxidante.

Sacha inchi is a euphorbiaceae known as the Inca peanut that is found in Peru in San Martin, Hu nuco, Amazonas, Loreto and Madre de Dios. Objective: to determine the activity of the phenolic compounds of sacha inchi seeds and its role in the color, durability, taste of food and drink. Material and Methods: this study was performed with sacha inchi seeds collected in Tarapoto by the National Institute of Agricultural Research and Extension (INIA) in the Center of Biochemistry and Nutrition, Faculty of Human Medicine USMP. The determination of total polyphenols was performed according to Aparicio et al. (1999), total tannins as described by Price and Butler (1977) and antioxidant activity by the ORAC method described by Prior and Cao (2000). Also, the ability to inhibit hydrogen peroxide according Wettasinghe and Shahidi (1999) and their reducing power by Srivastava et al. (2006). We worked with the oil and cake obtained of each sample obtaining hydrophilic and lipophilic extracts. Results: we found higher total polyphenol content, total tannins, higher reducing power, greater ability to inhibit hydrogen peroxide and increased antioxidant capacity in the hydrophilic extract of cake. Conclusions: cake hydrophilic extract of sacha inchi showed higher content of total polyphenols and tannins with antioxidant action.

Purple corn (Zea mays L.) phenolic compounds profile and its assessment as an agent against oxidative stress in isolated mouse organs.

This study was designed to determine the contents of total polyphenols, flavonoids, flavonols, flavanols, and anthocyanins of purple corn (Zea mays L.) extracts obtained with different methanol:water concentrations, acidified with 1% HCl (1 N). Another objective was to determine the antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and deoxyribose assay, individual phenolic compounds by high-performance liquid chromatography (HPLC), and endogenous antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], and total peroxidase [TPX]) activity and lipid peroxidation activity (thiobarbituric acid-reactive substances [TBARS] assay) in isolated mouse organs. Overall, the highest total content of polyphenols, anthocyanins, flavonoids, flavonols, and flavanols was obtained with the 80:20 methanol:water extract, acidified with 1% HCl (1 N). The 50% inhibitory concentration values obtained by the DPPH and ABTS assays with this extract were 66.3 µg/mL and 250 µg/mL, respectively. The antioxidant activity by the FRAP assay was 26.1 µM Trolox equivalents/g, whereas the deoxyribose assay presented 93.6% inhibition. Because of these results, the 80:20 methanol:water extract, acidified with 1% HCl (1 N), was used for the remaining tests. Eight phenolic compounds were identified by HPLC: chlorogenic acid, caffeic acid, rutin, ferulic acid, morin, quercetin, naringenin, and kaempferol. Furthermore, it was observed that the purple corn extract was capable of significantly reducing lipid peroxidation (lower malondialdehyde [MDA] concentrations by the TBARS assay) and at the same time increasing endogenous antioxidant enzyme (CAT, TPX, and SOD) activities in isolated mouse kidney, liver, and brain. On the basis of the results, it was concluded that the purple corn extract contained various bioactive phenolic compounds that exhibited considerable in vitro antioxidant activity, which correlated well with the decreased MDA formation and increase in activity of endogenous antioxidant enzymes observed in the isolated mouse organs. This warrants further in vivo studies with purple corn extracts to assess its antioxidant activity and other bioactivities.

Capacidad antioxidante y principales ácidos fenólicos y flavonoides de algunos alimentos / Antioxidant capacity and main phenolic acids and flavonoids of some foods

El presente estudio busca determinar la existencia de los antioxidantes: ácido clorogénico, cafeico y ferúlico, de los flavonoides rutina, quercetina y morina, así como la capacidad antioxidante de ocho alimentos peruanos. La identificación y cuantificación de los extractos hidroalcohólicos se realizó por Cromatografía Líquida de Alta Performance a 370 nm con fase móvil de agua pH 2,5 y acetonitrilo en gradiente utilizando un estándar externo. Se encontró mayor cantidad de ácido clorogénico en el sachaculantro (13,7mg/g) y en el huacatay (1,8mg/g); el sachamote, el tumbo, el olluco, el aguaymanto, la sachapapa morada y la pituca presentaron concentraciones mucho más pequeñas. El ácido ferúlico también se encontró en mayor cantidad en el huacatay (16,60mg/g) y en el sachaculantro (15,99mg/g), el olluco, el sachatomate, el tumbo, la sachapapa morada y la pituca mostraron cantidades mucho menores. Mayor concentración de ácido cafeico tuvieron el huacatay (3,98 mg/g) y el sachaculantro (0,95mg/g), el sachatomate, el tumbo, el aguaymanto, la sachapapa morada y la pituca registraron cantidades menores. El flavonoide rutina se presentó con mayor concentración en el huacatay (1,80 mg/g), en el sachaculantro (288,7ug/g) y en el olluco (142,22ug/g), el sachatomate, el aguaymanto, la pituca y la sachapapa morada tuvieron concentraciones menores. La quercetina se presentó en gran cantidad en el huacatay (2,996mg/g) y en menor cantidad en el sachaculantro (113,8 ug/g), tumbo, sachatomate y pituca mostraron cantidades menores. La morina sólo se presentó en huacatay (3,21mg/g) y en el sachaculantro (0,094mg/g). Para evaluar la capacidad antioxidante se determinó el coeficiente de inhibición al 50 por ciento del radical libre DPPH (1,1 difenil2picrilhidrazilo) siendo el huacatay el producto más potente en este aspecto (9,44mg/mL) seguido del aguaymanto (41mg/mL), la pituca (95,53mg/mL), el tumbo (101,1mg/mL), la sachapapa morada (109,27mg/mL), el sachatomate...

This study looks for the existence of antioxidants: chlorogenic, caffeic and ferulic acids aside from rutine, quercetin and morine flavonoids and for the expression of the anti oxidant capacity of eight Peruvian foods. The identification and quantification of hidroalcoholic extracts was carried out by High Performance Liquid Cromatography at 370 nm with mobile phase of water at pH 2,5 and acetonitrile in gradient using an external standard. Chlorogenic acid was found in grater quantities in Sachaculantro (13,7mg/g) followed and huacatay (1,8mg/g), sachatomate, tumbo, olluco, aguaymanto, sachapapa morada and pituca. Ferulic acid content was higher in huacatay (16,60mg/g) and sachaculantro (15,99mg/g), followed by aguaymanto, olluco, sachatomate, tumbo, sachapapa morada and pituca. The biggest concentration of caffeic acid was in the huacatay (3,98 mg/g) and in sachaculantro (288, 7ug/g), followed by olluco, sachatomate, aguaymanto, pituca, sachapapa morada. Quercetin was present in huacatay (2,996mg/g) and in sachaculantro (113,8 ug/g) where as tumbo, sachatomate and pituca had fewer cuantities. Morine was present in huacatay (3,21mg/g) and in sachaculantro (0,094mg/g). To evaluate the antioxidant capacity, the 50% inhibition coefficient of the DPPH (1,1 difenil-2pictilhidrazilo) free radical was determined showing that huacatay (9,44mg/mL) was the more potent followed by aguaymanto (41mg/mL), pituca (95,53mg/mL), tumbo (101,lmg/mL), sachapapa morada (109,27mg/mL), sachatomate (140mg/mL), olluco (147,29mg/mL), sachaculantro (213,86mg/mL). We demonstrate that the studied foods present antioxidant capacity and that they contain the great majotity of the phenolic compounds studied.