%0 Journal Article %T Optimization of Glutamine Peptide Production from Soybean Meal and Analysis of Molecular Weight Distribution of Hydrolysates %A Yanli Xie %A Xinhong Liang %A Min Wei %A Wenhong Zhao %A Baoshan He %A Qiyu Lu %A Quangong Huo %A Chengye Ma %J International Journal of Molecular Sciences %D 2012 %I MDPI AG %R 10.3390/ijms13067483 %X The process parameters of enzymatic hydrolysis and molecular weight distribution of glutamine (Gln) peptides from soybean meal were investigated. The Protamex £¿ hydrolysis pH of 6.10, temperature of 56.78 ¡ãC, enzyme to substrate ratio (E/S) of 1.90 and hydrolysis time of 10.72 h were found to be the optimal conditions by response surface methodology (RSM) for a maximal degree of hydrolysis (DH) value of 16.63% and Gln peptides content at 5.95 mmol/L. The soybean meal was hydrolyzed by a combination of Protamex £¿ and trypsinase so that DH and Gln peptides would reach 22.02% and 6.05 mmol/mL, respectively. The results of size exclusion chromatography indicated that the relative proportion of the molecular weight < 1000 Da fraction increased with DH values from 6.76%, 11.13%, 17.89% to 22.02%, most notably the 132¨C500 Da fractions of hydrolysates were 42.14%, 46.57%, 58.44% and 69.65%. High DH values did not lead to high Gln peptides content of the hydrolysate but to the low molecular weight Gln peptides. %K glutamine peptide %K soybean meal %K enzymatic hydrolysis %K response surface methodology %K molecular weight distribution %U http://www.mdpi.com/1422-0067/13/6/7483