Effects of enzymolysis method on the preparation of peptides from wheat flour

The preparation of wheat peptide by Alcalase hydrolysis of wheat flour was investigated in this paper. The effects of reaction parameters such as solid-liquid ratio, enzyme addition, and enzymolysis time were evaluated with the purity and yield of peptides as indexes by the single-factor experiment. The optimal enzymolysis conditions from the orthogonal test were as follows: the solid-liquid ratio of 1:7, enzyme addition (E/S) of 1.2%, reaction time of 2 h. The yield and purity of peptides were 83% and 72%, respectively. The configuration of enzymatic hydrolysate from different enzymolysis conditions was observed by the scanning electron microscope (SEM). The results showed that the particle size of the enzymatic hydrolysate was much smaller than that of the original material, and the particle size of the enzymatic hydrolysate changed with the degree of hydrolysis (DH). The molecular weight (MW) of peptides under different enzymolysis conditions was analyzed by gel filtration chromatography, and the results showed that the proportion of small peptides (<1 kDa) was up to 78.8%.