Antioxidant Properties of Sourdoughs Made with Whole Grain Flours of Hull-Less Barley or Conventional and Pigmented Wheat and by Selected Lactobacilli Strains.

The use of sourdough fermentation and whole grain flours in baked goods manufacturing are known to enhance their functional and nutritional features. In this context, it is necessary to select the most suitable lactic acid bacteria strains and flour combination to achieve this goal. A characterization of 70 lactobacilli strains based on pro-technological and nutritional properties was carried out. The screening allowed the selection of 10 strains that were used to ferment sourdoughs made with two varieties of common wheat, the conventional red-grained cv Aubusson, a blue-grained variety rich in anthocyanins cv Skorpion, and a hull-less barley variety, cv Rondo. From each fermented sourdough, a water soluble extract was obtained and evaluated for its antioxidant activity performed on cultured cells (RAW 264.7 murine macrophage) by assaying Reactive Oxygen Species (ROS) content. Sourdoughs made with pigmented wheat and barley, had an antioxidant activity greater than that recovered in those made with conventional wheat flour, in spite they have been inoculated with the same LAB strains. Results highlighted the interdependence between flour and the inoculated lactic acid bacteria that has to be taken into account for the development of healthy breads exploiting high functional value cereals through biotechnological processes.

Minerales, ácido fítico y γ-oryzanol en harinas integrales y salvados de tres variedades de arroz (oryza sativa l) cultivadas en venezuela / Minerals, phytic acid and γ-oryzanol in whole wheat flour and bran of three varieties of rice (oryza sativa l) grown in venezuela

El propósito de esta investigación fue determinar el contenido de algunos minerales, de ácido fítico y de γ-oryzanol en harinas integrales y salvados de tres cultivares (Cimarrón, Fonaiap 1 y Zeta 15) de arroz (Oryza sativa L) cosechados en Venezuela. Los minerales (Ca, Mg, Fe y Zn) fueron cuantificados por espectrofotometría de absorción atómica, mientras que el fósforo (P) y el ácido fítico fueron estimados a través de un método colorimétrico. El γ-oryzanol se cuantificó por HPLC. En general, el contenido de minerales fue mayor en la harina y en el salvado de la variedad Zeta 15. El contenido de P (400,0 ± 5,00 mg/100 g) y Mg (60,0 ± 0,00 mg/100 g) fue menor en la harina de la variedad Cimarrón, mientras que en los salvados de las distintas variedades se observaron valores significativamente altos de P (1860 ± 2,00 - 2185 ± 0,58 mg/100 g) y Ca (66,7 ± 1,15 ­ 73,3 ± 1,53 mg/100 g). Las tres variedades evaluadas representan importantes fuentes de ácido fítico y γ-oryzanol; sin embargo, la variedad Cimarrón fue la que exhibió las menores concentraciones de estos compuestos bioactivos. Basado en los resultados obtenidos, las harinas integrales y los salvados representan una fuente importante de minerales, de ácido fítico y de γ-oryzanol. La concentración de todos los microcomponentes es significativamente superior en los salvados con respecto a las harinas, lo que los convierte en una atractiva alternativa para la obtención de compuestos con actividad biológica de interés para la salud humana(AU)

The objective of this study was to determine the content of some minerals, phytic acid and γ-oryzanol in whole-grain flour and bran in three cultivars (Cimarrón, Fonaiap 1 y Zeta 15) of rice (Oryza sativa L) in Venezuela. The minerals were (Ca, Mg, Fe y Zn) quantified by Atomic Absorption Spectrophotometry while that the phosphorus (P) and phytic acid were determined using a colorimetric method. The γ-oryzanol was quantified by HPLC. In general, the mineral contents were higher in flour than bran in the cultivar Zeta 15. The P (400,0 ± 5,00 mg/100 g) and Mg (60,0 ± 0,00 mg/100 g) contents were lower in flour of the cultivar Cimarrón, while that were observed higher values of P (1860 ± 2,00 - 2185 ± 0,58 mg/100 g) and Ca (66,7 ± 1,15 ­ 73,3 ± 1,53 mg/100 g) in the bran of different cultivars. The three cultivars evaluated are an important source of phytic acid and γ-oryzanol; however, the Cimarrón cultivar exhibited the lowest concentrations of these bioactive compounds. Based on these results, whole-grain flours and brans may offer a good source of minerals, phytic acid and γ-oryzanol. The concentrations of all micro compounds evaluated were higher in the brans than the flours, this become the bran an attractive alternative to obtain compounds with biological activity of interest for human health(AU)