Phenylalanine removal effect on the peptide profile of hydrolyzed protein from wheat flour

Abstract

The effect of phenylalanine removal on the peptide profile of the protein hydrolysates from wheat flour wasinvestigated. Nine hydrolysates were prepared, using a successive association of a pancreatin and a crudeenzymatic extract obtained from pineapple peel (CE), and the effect of the order of enzymes addition, thereaction temperature, the enzyme: substrate (E:S) ratio, and the physical treatment of sample were examined.The analysis of peptide profile of hydrolysates was performed in two stages, that is before and after removingphenylalanine. The size-exclusion high performance liquid chromatography was used for performing thefractionation, followed by Correct Fraction Area technique for quantifying peptides and free amino acids.The process of phenylalanine removal improved the peptide profile of three hydrolyzed samples, but it didnot affect the five hydrolysates. The beneficial effect of this process is correlated with the increase of di- andtripeptides contents, or in reducing the amount of large peptides. The best peptide profile was obtainedafter phenylalanine removal by using pancreatin at E:S ratio of 4:100 at 50ºC for 210min, followed by CEat E:S ratio of 10:100 at 70ºC for 90 min.