Eletromicrografias de varredura de polvilhos doce e azedo

Abstract

Starch is a product extracted from edible parts of cereals, tubers, roots and rhizomes. Cassava starch can be called "polvilho", and can be classified as sweet or sour if fermented. It is mainly used in baking, as in the production of cheese bread and cookies. The objective of this work was to evaluate if there is a difference in the starch granule of commercial sweet and sour cassava starches, as well as to compare if there is a difference between them and starch obtained without industrial processing, using the scanning electron microscopy (SEM) as a tool. The extracted starch was obtained from washed and crushed roots, the liquid obtained was sieved, centrifuged and the sediment dried in an air circulation oven at 45 °C. After obtaining the dry starch, the stubs were prepared with double carbon tape and dipped in the powder sample. This last procedure was also performed for the commercial sweet and sour cassava starches. Then, the gold bath was performed for analysis in the SEM. The scanning electron micrographs allowed the visualization of the cassava starches providing the observation of sizes ranging from 9.67 μm to 16.54 μm and the shapes of the granules that were rounded, oval, pentagonal and polygonal. Little difference was observed between the three samples of starch studied, both in format and size of the granules, the largest difference being found on the surface of the sour cassava starch granule from fermentation.