Effects of Hydrolysis Ratio on the Structure and Adsorption Properties of Porous Starch

Abstract

This study was carried out to investigate the effects of hydrolysis ratio on the structure and adsorption properties of porous starch. The starches with different hydrolysis ratios were prepared by enzymolysis (combination of α-amylase and glucoamylase), and its adsorption capacity was evaluated by using methylene blue (MB) and soybean oil as adsorption objects. The results suggest that crystallinity, specific surface area and adsorption capacity of porous starch were gradually improved with the increase of hydrolysis degree. The crystallinity of native starch was increased by enzymolysis from 28.43±0.23% to 34.70±0.69%, and the specific surface area was increased from 0.58±0.002 m2/g to 1.82±0.014 m2/g. Moreover, the adsorption capacity toward (MB) was increased from 2.88 mg/g to 3.87 mg/g at 25°C, which was accurately described by the pseudo-first-order kinetic model, and the oil absorption ratio was also greatly improved from 23.2±0.16% to 76.1±0.11%. Thus, the properties of porous starch can be adjusted by controlling the hydrolysis ratio to meet different needs in the market.