Amido de batata-doce cultivar BRS Amélia modificado por fermentação: caracterização físico-química, teor de amilose, capacidade de expansão e atividades biológicas

Abstract

The sweet potato, cultivar BRS amélia, is easy to grow and can be produced throughout the year. The main constituent of tuberous roots is starch. The modification of starch by fermentation causes desirable characteristics to the starch in product formulation, including expansion capacity. The effect of fermentation time on the starch of sweet potato cultivar BRS Amélia was studied. Fermentations were carried out at times of 0, 20, 40 and 60 days. The parameters of pH, titratable acidity, and soluble solids, expansion property, amylose content and biological activities were evaluated. There was a decrease in pH during fermentation, while acidity increased, as expected. Soluble solids decreased, which shows that they were being consumed during fermentation. The starches obtained after drying also had the expected behavior, with a decrease in pH and soluble solids, and an increase in acidity. There was a decrease in amylose concentration according to fermentation time, with the lowest concentration at 60 days. Cheese breads were developed to evaluate the expansion capacity. The cheese breads with the greatest expansion capacity were those developed with starches fermented for 60 days. All starches showed antioxidant activity against 2,2- diphenyl-1-picrylhydrazyl (DPPH), nitric oxide and hydroxyl radicals, with emphasis on activities against the nitric oxide radical. With the exception of native starch, all starches showed anti-inflammatory activity. In terms of antimicrobial activity, AN (nonfermented) presented the greatest inhibition zone for the microorganism Staphylococcus aureus. None of the starches showed activity against the Escherichia Coli microorganism. Among fermented starches, starch with 20 days of fermentation showed the greatest inhibition halo. It was observed that starches were capable of causing bacterial death of the microorganism S. aureus.