Effects of Different Reagent on the Separation of Starch and Protein in Corn Endosperm

Abstract

Corn and corn flour were steeped with different chemical reagents ,sulfurous acid (0.1%, 0.2%, 0.1%)、NaOH (0.1%, 0.3%, 0.5%)、alcohol (65%, 75%, 65%)、lactic acid (0.3%, 0.5%, 0.3%)、L - cysteine (0.6%, 1.0%, 1.4%) ,using distilled water as control. The separation of starch and protein in corn endosperm steeped under different reagents were analyzed using the amount of free starch measuring by iodine colorimety.The results show that under the action of different concentration of NaOH、sulfurous acid、lactic acid,the measured value of free starch in both corn and corn flour were increased and were higher than control,with the extending of the soak time and increase of reagent concentration.The effect of NaOH is the best,but when the NaOH concentration was above 0.5%, the amount of free starch began to decline. The starch granules were destroyed by the high concentration of alkali. The effect of Sulfite solution is good also, and the observed value of free starch slightly higher than the lactic acid. The effect of different concentration L-cysteine on corn was almost the same as control,but the effect of separation on corn flour was obviously enhanced and better than sulfurous acid,especially concentration above 1.0%.There was no starch granules out of corn and corn flour by alcohol soaking.