Combining Plant Proteins to Achieve Amino Acid Profiles Adapted to Various Nutritional Objectives-An Exploratory Analysis Using Linear Programming.

Laurianne Dimina,Jean-François Huneau,François Mariotti,Didier Rémond

doi:10.3389/fnut.2021.809685

Abstract

Although plant proteins are often considered to have less nutritional quality because of their suboptimal amino acid (AA) content, the wide variety of their sources, both conventional and emerging, suggests potential opportunities from complementarity between food sources. This study therefore aimed to explore whether, and to what extent, combinations of protein ingredients could reproduce an AA profile set as a nutritional objective, and to identify theoretical solutions and limitations. We collected compositional data on protein ingredients and raw plant foods (n = 151), and then ran several series of linear optimization to identify protein ingredient mixes that maximized the content in indispensable AA and reproduced various objective profiles: a “balanced profile,” based on AA requirements for adults; “animal profiles” corresponding to conventional animal protein compositions, and a “cardioprotective profile,” which has been associated with a lower cardiovascular risk. We assumed a very good digestibility of plant protein isolates. As expected, obtaining a balanced profile was obvious, but we also identified numerous plant protein mixtures that met demanding AA profiles. Only for particularly demanding profiles, such as mimicking a particular animal protein, did solutions require the use of protein fractions from more specific sources such as pea or canola. Optimal plant blends could mimic animal proteins such as egg white, cow milk, chicken, whey or casein with a similarity reaching 94.2, 98.8, 86.4, 92.4, and 98.0%, respectively. The limiting constraints were mainly isoleucine, lysine, and histidine target contents. These different solutions offer potential for the formulation of mixtures adapted to specific populations or the design of plant-based substitutes. Some ingredients are not commercially available but they could be developed.

Highlights

Western countries are entering a new nutritional transition phase that aims to rebalance the dietary plant:animal protein ratio
Plant proteins are often considered as being of poor nutritional quality, mainly because of their lower content in indispensable amino acids, some of which being low in one amino acid, namely lysine, when compared to animal protein or amino acid requirement profiles
When ranking the protein ingredients in the database in terms of their Indispensable Amino Acid (IAA) contents, we found that some levels were high in plantbased protein ingredients in particular

Summary

Introduction

Western countries are entering a new nutritional transition phase that aims to rebalance the dietary plant:animal protein ratio. Plant proteins are often considered as being of poor nutritional quality, mainly because of their lower content in indispensable amino acids, some of which being low in one amino acid, namely lysine, when compared to animal protein or amino acid requirement profiles This is reflected by poorer values when the quality of these proteins is assessed using methods based on the concept of limiting amino acids, such as the Protein Digestibility Corrected Amino Acid Score (PDCAAS) or the more recently recommended Digestible Indispensable Amino Acid Scores (DIAAS) [2]. Combining two protein sources with low PDCAAS can provide balanced and sufficient quantities of all AA that will cover AA requirements Beyond this basic nutritional objective, it may be advocated that animal proteins have higher nutritional value in specific populations such as the elderly, because of their greater anabolic capacity, during the postprandial period [4]. Again, mixing protein sources could offer a means to define specific amino acid profiles

Objectives

Methods

Results

Discussion

Conclusion