title: A GC-FID method for analysis of lysinoalanine.
abstract: Lysinoalanine (LAL) is an unwanted byproduct, which is formed during the processing of protein and protein-containing foods and feeds. A GC method for the quantitative analysis of LAL under conventional chromatographic conditions has been developed. The method was applied to the analysis of pure standard substances, boiled eggs, commercial caseinates, fresh cheese, fresh cheese made from milk supplemented with caseinate, and fresh cheeses adulterated with caseinate after cheese making process. Results demonstrated the reliability of the GC capillary chromatography for the analysis of LAL in protein containing foods. LOD and LOQ of 50 and 152 ppm of LAL in protein, respectively, were achieved. Range of linearity, precision, and accuracy of the method, measured using diaminopimelic acid as internal standard, were satisfactory for quantification purpose. The method might also be suitable for the quantitative analysis of other amino acids such as lysine and arginine. Results also indicated the utility of this methodology for detecting protein quality of egg products and caseinates as well as fresh cheese adulterations.
authors: Instituto de Fermentaciones Industriales, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
authors: Antonia
authors: A
authors: Montilla
authors: José Angel
authors: JA
authors: Gómez-Ruiz
authors: Agustín
authors: A
authors: Olano
authors: María Dolores
authors: MD
authors: del Castillo
mesh_terms: D002364:Caseins / Q000032:analysis; D002611:Cheese / Q000032:analysis; D002849:Chromatography, Gas / Q000379:methods*; D004531:Eggs / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D008241:Lysinoalanine / Q000032:analysis*
chemical_list: D002364:Caseins; D008241:Lysinoalanine