Phenylketonuria: Protein content and amino acids profile of dishes for phenylketonuric patients. The relevance of phenylalanine

• Published in: Food chemistry 2014-04, Vol.149, p.144-150
• Main Authors: Pimentel, Filipa B., Alves, Rita C., Costa, Anabela S.G., Torres, Duarte, Almeida, Manuela F., Oliveira, M. Beatriz P.P.
• Format: Article
• Language: English
• Subjects: Adult; Amino acids; Amino Acids - analysis; Amino Acids - metabolism; Aminoacid disorders; Biological and medical sciences; Chromatography, High Pressure Liquid; Diet - standards; Errors of metabolism; Food Analysis; Humans; Low protein foods; Medical sciences; Metabolic diseases; Phenylalanine; Phenylalanine - analysis; Phenylalanine - metabolism; Phenylketonuria; Phenylketonurias - diet therapy; Phenylketonurias - metabolism; Protein content
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2013.10.099

•Protein and amino acid levels of dishes conceived for PKU patients were assessed.•Protein and Phe results differed from those of food composition databases.•In contrast to other amino acids, Phe and protein contents are correlated. Phenylketonuria is an inborn error of metabolism, involving, in most cases, a deficient activity of phenylalanine hydroxylase. Neonatal diagnosis and a prompt special diet (low phenylalanine and natural-protein restricted diets) are essential to the treatment. The lack of data concerning phenylalanine contents of processed foodstuffs is an additional limitation for an already very restrictive diet. Our goals were to quantify protein (Kjeldahl method) and amino acid (18) content (HPLC/fluorescence) in 16 dishes specifically conceived for phenylketonuric patients, and compare the most relevant results with those of several international food composition databases. As might be expected, all the meals contained low protein levels (0.67–3.15g/100g) with the highest ones occurring in boiled rice and potatoes. These foods also contained the highest amounts of phenylalanine (158.51 and 62.65mg/100g, respectively). In contrast to the other amino acids, it was possible to predict phenylalanine content based on protein alone. Slight deviations were observed when comparing results with the different food composition databases.