Phenylalanine and protein profiling of 30 Egyptian foods for phenylketonuria: first single-center study

Background Phenylketonuria (PKU) is a rare metabolic disorder requiring strict lifelong dietary restriction of phenylalanine (Phe). Managing PKU in Egypt remains challenging due to the absence of localized data on Phe content in commonly consumed Egyptian foods. Aim This study aimed to directly quantify the Phe and protein content in 30 frequently consumed Egyptian foods to support dietary management for Egyptian PKU patients. Patients and methods This study was conducted between October 2024 to April 2025 to determine the Phe and total protein content in 30 different types of commonly consumed traditional Egyptian food items, including vegetables, fruits, Grains and legumes, wheat products, and baby foods. Food samples were collected from local markets in Zagazig, Sharkia, Egypt. Total protein was determined using the Kjeldahl method, and Phe content was analyzed using high-performance liquid chromatography. All values were expressed per 100 g of fresh weight. Results Phe levels varied widely across food groups. Vegetables like Molukhiyah and grape leaves showed elevated Phe content (585 and 341 mg/100 g, respectively), while cauliflower and potatoes had the lowest values (43 and 87 mg/100 g). Fruits such as figs and dates contained low Phe (29–64 mg/100 g), whereas pomegranate showed a higher concentration (150 mg/100 g). Legumes—including fava beans and black-eyed peas—had the highest Phe content (over 1200 mg/100 g). Wheat-based products like baladi bread and white flour also exhibited high Phe concentrations (1030 and 699 mg/100 g, respectively). Commercial baby foods such as Cerelac and cornflakes had moderate levels (170–253 mg/100 g). Conclusion This is the first study in Egypt to provide direct laboratory data on Phe and protein content in local foods. The findings highlight the necessity of region-specific food analysis for PKU dietary management.