Extração, caracterização e propriedades tecnológicas do amido de taioba (Xanthosoma sagittifolium)

Abstract

Non-conventional food plants (PANC) are plants that are rarely included in the diet of the world population. Among these, taioba (Xanthosoma sagittifolium) in its leaf and tuber constituents can be consumed as products and by-products that are a source of starch. This research aims to highlight the nutritional and functional characteristics and the possibilities of technological applications on an industrial scale of Amazonian starches such as that extracted from taioba. The results were obtained 4.34 g/100g of proteins, 0.71 g/100g of lipids, 88.13 g/100g of carbohydrates. 28.73% of amylose and 71% of amylopectin were found, being considered a starch with a high amylose content. In the determination of minerals, taioba starch presented significant values for the macrominerals phosphorus. According to the colorimetric analysis, the starch has an average of 87.67 whiteness index, being recommended for preparing white or neutral products, as there will be no change in the color of the final product. According to scanning electron microscopy, taioba starch presented granules with circular shapes, smooth surfaces and dimensions of around 4.23µm to 9.93µm. The size and shape of the granules act directly on properties such as gelatinization and solubility. In the thermogravimetric analysis, a peak with mass loss was observed at 300ºC (Tonset) and with a maximum peak at 329.9 ºC (Tendset), which may be related to loss of glycosidic bonds. As for infrared spectroscopy, starch showed organic chemical compounds such as alcohols, cellulose, in addition to hydroxyl groups constituents of glucose, cellulose and hemicellulose, related to the formation of starches. According to x-ray diffraction, taioba starch presented reflection intensities at 16, 17, 18 and 23° at 2θ angles and crystallinity (63.52%) being characteristic of a type A starch structure. Regarding the temperature properties of paste (81.9), maximum viscosity (2062.66), final viscosity (2480.66), and technological properties, the starch expressed aspects that indicate its functionality for use in products such as thickeners, bakery products, sauces, among others . Taioba starch presented considerable characteristics to be applied in new products. These results demonstrate the importance of inserting new raw materials for industrial segments, adding value to amazonian sources.