Strategies Used in Production of Phenylalanine‐Free Foods for PKU Management

Abstract

Phenylketonuria (PKU) is one of the most widespread dysfunctions caused by an inheritable problem in the phenylalanine metabolism. In this metabolic disease, gene mutations in phenylalanine hydroxylase (PAH) result in phenylalanine accumulation that causes varying degrees of mental retardation. The most effective treatment is restriction of phenylalanine in diet provided through different strategies including combination of low-protein foods, hydrolyzing of protein-rich foods, or use of protein substitutes. Meat and meat products, sea foods, milk and infant formula, cereal products, and beans are among the modified foods for PKU management. Elimination of phenylalanine from food presents major technological, nutritional, and organolleptic challenges because protein, as an essential structurebuilding and nutritional element, is removed. In addition, following this program is laborious, boring, and restrictive for both patients and their families. This paper reviews the current findings about PKU and the recent developments in the production of phenylalanine-free foods. Also, the nutritional requirements and challenges encountered by PKU individuals and food technologists are finally discussed.

A 3 Year Longitudinal Prospective Review Examining the Dietary Profile and Contribution Made by Special Low Protein Foods to Energy and Macronutrient Intake in Children with Phenylketonuria

“…The starch sources from SLPFs, bread and pasta, eaten by children in our study were derived from starch isolated from wheat, maize and rice. Isolated starches are refined, having different physiologic properties compared to complex starch forms, and foods containing these may have a higher glycaemic index than those made from wheat flour [ 29 , 30 ]. However, a high intake of sugar from regular sweet drinks is also problematic.…”

Improvement, cloning, and expression of an in silico designed protein enriched with large neutral amino acids in Pichia pastoris for possible application in phenylketonuria

“…An adequate amount of natural proteins required by the body cannot be obtained from food without having excessive levels of Phe in it, as 2.4%–9.0% Phe is always present in natural proteins. The cornerstone of dietary management involves treatment using Phe free protein substitutes, low protein special foods, and also monitoring and supervising a well‐balanced diet (Soltanizadeh & Mirmoghtadaie, ). These supplements and medical formula are very expensive and there is a vast disparity in the cost and access to these dietary products (Quintana et al, ).…”

“…This event increases the level of Phe in the brain in PKU, leading to various complications (Pardridge, 1998). One way of achieving a low level of Phe in blood and brain is by the intake of high levels of LNAA (Soltanizadeh & Mirmoghtadaie, 2014;van Vliet et al, 2015van Vliet et al, , 2018van Vliet et al, , 2019. Supplementation of LNAA decreases the uptake of Phe and consequently decreases the level of Phe in the brain, as a result of competition for the common transporter in the gastrointestinal tract and BBB.…”

Reduction of l-phenylalanine in protein hydrolysates using l-phenylalanine ammonia-lyase from Rhodosporidium toruloides

“…Nevertheless, some of them are not available worldwide [9] or they have a high cost, in particular for undeveloped countries [25]. In many developed countries, social security systems completely refund the cost of PKU treatment; however, in other countries (particularly undeveloped and developing countries), the cost of special low-protein or protein-free foods is not totally paid for the social security systems and the patient must be in charge of the treatment costs [13].…”