Production of functional dairy product low of phenylalanine content and supplemented with probiotics bacteria

Abd El-Rahman, Manar; Sidkey, Nagwa Mahmoud; Al Kassaby, Aziza; Effat, Baher; El-Sayed, Hoda; Mehnna, Nayra

doi:10.21608/ijtar.2025.376291.1121

Production of functional dairy product low of phenylalanine content and supplemented with probiotics bacteria

Document Type : Original Article

Authors

¹ Dairy Department, National Research Centre, Egypt

² Prof. Of Microbiology &Biotechnology, Faculty of Science, Al-Azhar University (girls branch)

³ Botany & Microbiology Department, Faculty of Science, Al-Azhar University

⁴ Dairy Department, National Research Centre. Egypt

⁵ 33 El Bohouth St. (former El Tahrir st.), Dokki, Cairo, Egypt

10.21608/ijtar.2025.376291.1121

Abstract

The present study was designed to produce new functional dairy products fortified with probiotics for phenylketonuria (PKU). The first step was determined the phenylalanine content in skim milk and whole milk by HPLC as the base constituent for the product. The different enzymes to hydrolyze the protein of skim milk and whole milk were detected. Next, the usage of barium sulfate or mixed probiotics to lowering the release of phenylalanine from hydrolysates protein was evaluated. Finally, the functional low phenylalanine dairy product was prepared by adding 2% probiotics to the skim milk hydrolysate. To confirm that the final product was free from phenylalanine, the phenylalanine content of the product was determined by HPLC. The product was chemically, microbiologically analysis. The significant findings showed that the concentrations of phenylalanine in skim milk and whole milk were 2.14 and 2.55 mg/mL, respectively. The amount of phenylalanine in skim and whole milk could be eliminated 100% by using either papain or papain combined with protease enzymes and then followed by the adsorption agent barium sulphate. The data showed that after treating skim milk, the probiotic bacteria could consume the hydrolyzed protein. The percentages of elimination for skim milk hydrolysates containing papain alone and papain with protease were 100 and 75.23 %, respectively. The chemical composition of functional products had percent of moisture, ash, protein and fat as 84.2,8,5, 2.23 and 0.5%, respectively and free from phenylalanine. The final products contained probiotics (different strains of Lactobacillus, Bifidobacterium and Streptococcus) with high level during storage.

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