Burstad, K. M.; Fons, A.; Kisch, A. R.; Cladis, D. P.; Hill Gallant, K. M.

Objective: Plant protein is gaining interest for dietary phosphorus management in CKD due to its potential benefits, including possible lower phosphorus bioaccessibility. However, data on phosphorus remain limited, particularly for processed plant protein products. This pilot study aimed to compare phosphorus bioaccessibility of processed plant protein products with their animal protein counterparts, using in vitro simulation of adult human digestion. Methods: Soy protein (n=16), pulse protein (n=17), and animal protein (n=13) products representing food categories of beef, dairy, sausage/bacon, chicken/turkey were evaluated for phosphorus bioaccessibility using in vitro digestion based the INFOGEST protocol, followed by dialysis of the final digesta. Pre-digestion samples, final digesta, and final dialysate were analyzed for phosphorus content to calculate total and bioaccessible phosphorus and percent phosphorus bioaccessibility. Results: Average percent phosphorus bioaccessibility of all processed soy and pulse products studied ranged from 32-100%, while animal products ranged from 81-100%. Average bioaccessible phosphorus and bioaccessible phosphorus-to-protein ratio were lower for many soy and pulse protein beef and chicken/turkey alternatives, soy protein milk alternatives, and pulse protein sausage alternatives than their animal protein counter products. Conclusion: Some soy and pulse protein products offered lower bioaccessible phosphorus per 100g serving and per gram of protein than their animal protein counterparts. Thus, this pilot study suggests that certain processed plant protein products may be acceptable to include in a diet for phosphorus management in CKD. However, more data on phosphorus bioaccessibility in a larger number and variety of processed plant-based protein products is needed to better inform individualized guidance.