UV Spectrophotometric analysis of phosphate content in plant-based milk alternatives in relation to Advanced Chronic Kidney Disease

Abstract

Background: Managing dietary phosphorus is critical in advanced chronic kidney disease (CKD), where excess intake can lead to complications such as hyperphosphataemia. Plant-based milk alternatives (PBMAs) are increasingly consumed, yet their phosphorus content, particularly in relation to phosphate additives, remains poorly defined in the UK. Objective: This study aimed to quantify and compare the total phosphorus content and phosphorus-to-protein ratio (PPR) in a range of commercially available UK PBMAs, with and without phosphate additives, using UV spectrophotometric analysis. Materials & Methods: Fourteen PBMAs (from seven plant sources) were analysed using the molybdenum blue method. Samples were categorised based on presence or absence of phosphate additives. Phosphorus content (mg/100g) and PPR (mg/g protein) were calculated and compared with previously documented data for cow’s milk. Results: PBMAs with phosphate additives contained significantly higher phosphorus levels (mean 58.47 mg/100g) than those without (mean 7.38 mg/100g; p < .001). Similarly, PPR was substantially higher in additive-containing PBMAs (mean 197.76 mg/g) versus additive-free options (mean 16.25 mg/g; p < .001). Some PBMAs with additives had phosphorus content and PPR values exceeding those of cow’s milk, raising concerns for phosphate management in CKD. Conclusion: Phosphate additives significantly increase the phosphorus load and PPR of PBMAs, which may not be readily apparent to consumers or clinicians due to insufficient labelling. For patients with advanced CKD, selecting additive-free PBMAs may support better phosphorus control and dietary management.