Effect of enzymatic hydrolysis on some physicochemical properties of root and tuber granular starches

Food Science and Technology (Campinas)

Thaís De Souza Rocha¹  Ana Paula De Almeida Carneiro¹  Celia Maria Landi Franco¹ 

[1] ,Universidade Estadual Paulista Instituto de Biociências, Letras e Ciências Exatas Departamento de Engenharia e Tecnologia de AlimentosSão José do Rio Preto SP ,Brasil

关键词: α-amylase;    granular starch;    structure;    α-amilase;    amido granular;    estrutura;   

DOI  :  10.1590/S0101-20612010000200039

来源: SciELO

【 摘 要 】

Enzymatic hydrolysis of granular starch is an important tool to provide information about granule structure. Cassava, sweet potato, Peruvian carrot, and potato starches were hydrolyzed by bacterial α-amylase at 37 °C for 48 hours, and the physicochemical properties of the residues from hydrolysis were determined. Cassava starch was the most susceptible to enzyme displaying 20.9% of hydrolysis, whereas potato starch was the most resistant with 5.9%. The granule average size varied from 10.8 to 23.4 μm for Peruvian carrot and potato starches, respectively. With the use of SEM, a smooth granule surface was observed for all native starches. Cassava and sweet potato starches displayed an A-type X-ray diffraction pattern, while Peruvian carrot and potato starches showed a B-type pattern. After hydrolysis, cassava, sweet potato, and Peruvian carrot starches showed some well degraded granules, whereas potato starch presented a slight sign of degradation. The amylose content of the starches decreased with hydrolysis for cassava, sweet potato, and Peruvian carrot starches and was kept unchanged for the potato starch. As expected, intrinsic viscosity and pasting properties decreased for all hydrolyzed starches. There is no difference between thermal properties of native and hydrolyzed starches. These results suggested that hydrolysis occurred in amorphous and crystalline areas of the granules. The B type diffraction pattern in conjunction with the big granule size of the potato starch may have contributed to the greatest resistance of this starch to hydrolysis.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License