Effect of Annealing, Acid Hydrolysis and Branching Enzyme on Dioscorea schimperiana Starch Technological and Functional Properties

Aims: To assess its technological aptitude and functional properties, Dioscorea schimperiana starch was submitted to various treatment of technological importance and its properties was evaluated.

Methodology: For this aim, the starch extracted from Dioscorea schimperiana tubers and was submitted to annealing, acid hydrolysis and to a branching enzyme (1, 4-α-glucan branching enzyme). Afterward, Fourier-transform infrared spectroscopy (FTIR), gelatinization profile, physicochemical and functional properties of the samples was recorded.

Results: FTIR spectra show the introduction and withdrawal of bond in modified samples. The thermal properties (DSC) of starch were not affected by annealing (AS) and enzymatic treatment (EBS). No peak temperature and gelatinization profile were observed for acid hydrolyzed samples (AHS) on Rapid Visco Analyzer. Annealing and enzyme treatment lead to an increase of the starch peak viscosity of while reducing its breakdown. The functional properties of the starch such as swelling capacity, least swelling concentration and water binding capacity were increased by annealing. Acid hydrolysis significantly increases in vitro digestibility of D. schimperiana starch while no significant change was observed after annealing and enzymatic modification, thus presenting it as particularly resistant to digestion.

Conclusion: This study suggests that annealing can be considered for the production of D. schimperiana modified starch with high technological and functional properties.