One-pot preparation of V-type porous starch by thermal-stable amylase hydrolysis of normal maize starch in hot aqueous ethanol solution.

The V-type porous starch (VPS) displays remarkable adsorption capability, and has potential for encapsulating guest compounds within its unique single helical cavity. In this investigation, VPS was produced via a "one-pot method" utilizing thermostable α-amylase in a hot ethanol solution. The study demonstrates that the activity of thermostable α-amylase remains high, reaching up to 86 % when employing a 40-50 % ethanol concentration, and up to 74 % with ≤70 % ethanol concentration. Furthermore, the enzyme exhibits robust stability at 90 °C for up to 10 h of reaction time. The resultant VPS exhibits enhanced V-type crystallinity and superior adsorption capacity compared to conventional A-type porous starch (APS). Notably, the hydrolysis of normal maize starch (NMS) by thermostable α-amylase in a 50 % ethanol solution at 90 °C yields 49.36 % VPS, which manifests a densely porous distributed structure. Additionally, the VPS is characterized by superior oil adsorption capacity (253.11 %), specific surface area (38.89 m/g), and total pore volume (0.147 cm/g).