Article

Propiedades químicas, fisicoquímicas y reológicas del almidón extraído de la nuez del Orinoco (Caryodendron orinocense Karst)

Acta científica venezolana 01/2007; 58(2):52-57.

ABSTRACT El objetivo del estudio fue extraer, blanquear, purificar y caracterizar el almidón de la nuez (nuez del Orinoco) del árbol del nogal (Caryodendron orinocense Karst). Al almidón obtenido se le evaluó la composición proximal, propiedades químicas, físicas y fisicoquímicas, también se evaluaron sus propiedades reológicas y morformétricas, usando el viscoamilógrafo de Brabender, el viscosímetro de Brookfield y el microscopio electrónico de barrido (SEM). Los parámetros reológicos evaluados fueron la viscosidad aparente, perfil de gelatinización y estabilidad del gel. Los resultados del perfil reológico señalan, que este almidón mostró menores valores de fragilidad de los gránulos y menor tendencia a la retrogradación que el almidón de yuca comercial. Este almidón también mostró un mayor rango de temperatura de gelatinización que el almidón de yuca comercial; variando esta, desde a 87 a 90 °C. Los gránulos de almidón presentaron forma esférica y un promedio en tamaño que varia de 7,35 a 9,15 µm de ancho y de 5,08 a 20,30 µm de largo. Los resultados permiten inferir los usos de este almidón en diferentes industrias; una de ellas, sería la industria de alimentos; donde es posible su aplicación en productos donde la retrogradación disminuye la calidad, como es el caso de productos refrigerados.
The goal of the study was the isolation, blanching, purification and characterization of the starch from the nut of the orinoconut tree (Caryodendron orinocense Karst). The proximate composition, chemical, physical, physicochemical characteristics and rheological properties of the isolated starch were evaluated. In order to determine their functional properties, the following parameters using the viscoamylograph Brabender and Brookfield viscosimeter profile were evaluated: apparent viscosity, gelatinization profile, breakdown, consistency, setback, and gel stability. In addition, the microstructure was studied by Scanning Electronic Microscopy (SEM). The results pointed out that the starch has a lower breakdown, consistency and setback, than those showed by commercial cassava starch. Moreover, the gelatinization temperature range was higher than those shown by the commercial cassava starch. Orinoconut starch granules are round and with a size ranging from 7.35 to 19.15 µm of wide and from 5.08 to 20.30 µm length. The results allow inferring the possible uses of this starch in different industries; one of them would be at the frozen food industry.

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