%0 Journal Article
%T Padroniza£¿£¿o de m¨¦todo anal¨ªtico para avalia£¿£¿o do grau de exposi£¿£¿o da fenilalanina em hidrolisados de case¨ªna, por espectrofotometria derivada segunda
%A Barbosa
%A Cristiane M¨¢rcia da Silva
%A Morais
%A Harriman Aley
%A Silva
%A Viviane Dias Medeiros
%A Oliveira
%A M£¿nica Cristina de
%A Silvestre
%A Marialice Pinto Coelho
%J Revista Brasileira de Ci¨ºncias Farmac¨ºuticas
%D 2002
%I Scientific Electronic Library Online
%R 10.1590/S1516-93322002000100012
%X dietetic formulations for phenylketonurics generally contain free or low phenylalanine protein hydrolysates. several hydrolytic conditions have been proposed in the literature to increase phenylalanine (phe) exposure, in order to favor its subsequent removal. the second derivative spectrophotometry (sds), a fast, simple and low cost analytical method, was used, in this work, for the determination of phe exposure in different casein hydrolysates, prepared by using papain, and also for the characteriztion of aromatic amino acids. a temperature of 37 oc, an enzyme:substrate ratio of 4% and a ph 7.5 showed to be the most suitable condition for preparing phenylketonuric diets, since they led to the highest phe exposure. concerning the characterization of aromatic amino acids, a good separation of tyrosine (tyr) and tryptophan (trp) peaks was obtained in ph 13.0, using the sds. moreover, the second derivative spectra of the aromatic amino acids were similar to those of the protein hydrolysates.
%K aromatic amino acid
%K casein hydrolysate
%K second derivative spectrophotometry
%K phenylalanine
%K phenylketonuria.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1516-93322002000100012&lng=en&nrm=iso&tlng=en