MOLECULAR AND GRANULE CARACTERIZATION OF OZONE-MODIFIED ARRACACHA STARCH

Starches present a wide application in food and non-food industries. However, native starches present some limitations to industrial application. The alternative to overcome these limitations is use technologies to modify the starch. Ozone is an attractive chemical technology of starch modification because it decomposes into oxygen, leaving no toxic residues in food or environment, being considered a “green friendly” technology. This work aimed to evaluate the effect of ozone technology in the arracacha starch granules morphology and molecules. Arracacha starch suspensions (10% m/m in dry basis) were processed using ozone (46.7 mg O3/L) at a constant gas flow of 1 L/min up to 30 min. The samples were analyzed in relation to their carbonyl, carboxyl, amylose and reducing sugar contents, pH, molecular size distribution, starch granule morphology, and particle size distribution. The carbonyl and carboxyl groups content increased with increasing ozonation processing time, and due to the presence of carboxylic groups, the acidity of the starches suspensions also increased. Therefore, during ozonation process, the hydroxyl group were oxidized, forming the carboxyl and carbonyl groups. The presence of these compounds might lead to starches with higher paste clarity and stability. It was noticed a reduction of amylose content and molecular size, with a consequent increase of the reducing sugar content, highlighting the molecular depolymerization. The ozonated arracacha starch did not presented alterations on the granule surface and morphology, but they presented a slightly increase on the particle size distribution. Therefore, the ozone process was effective in change the arracacha starch granules structures, which imply in properties changes, giving new possibilities for arracacha starch industrial applications.