Abstract:The effects of enzyme content, enzyme ratio and time on hydrolysis rate and oil-absorption rate of porous rice starch, which was prepraed byα-amylase and glucosidase, were studied by using the common southern rice starch from China as raw materials The optimized conditions for preparation of porous rice starch were as follows: enzyme content,1.0%, enzyme ratio, 1:12, processing time, 12 h, and the hydrolysis rate and oil-absorption rate of porous starch were 50% and 96.3%. Under this condition,, the original starch and porous rice starch (hydrolysis rate of 30%, 40% and 50%) were selected for strengthing thereaction of Zn complex by PEF treament with zinc-acetate solution (0.1 mol/L), and the conditions were as follows: voltage, 20 V, frequency, 1 kHz, fluid rate, 24 mL/min, treatment durations, 2.88×103 μs, 8.64×103 μs and 14.4×103 μs. In addition, the microstructure of the starch complex was investigated by scanning electron microscope (SEM) and infrared spectroscopy (FT-IR), and the zinc content of starch-Zn complex was determined by atom absorption spectroscopy. Consequently, the highest zinc contentwas 352.85 mg / 100 g with the hydrolysis-rate of 40% and PEF treatment time of 2.88×103 μs.
