Nutritional value in sustainability assessment of protein-rich ingredients and foods: A ‘farm-to-faeces’ approach

• Published in: Journal of cleaner production 2023-09, Vol.417, p.137864, Article 137864
• Main Authors: Draijer, Nynke, Rivera del Rio, Andrea, Lie-Piang, Anouk, Janssen, Anja E.M., Boom, Remko M.
• Format: Article
• Language: English
• Subjects: animals; digestibility; digestible protein; digestion; environmental impact; fractionation; ingredients; Life cycle assessment; Mild fractionation; Pea protein; peas; Processing history; Protein digestibility; whey; whey protein isolate
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2023.137864

The environmental impact of ingredients and foods is often assessed from production of the raw materials up to consumption (‘farm-to-fork’ system boundaries). Comparing animal-to plant-based protein ingredients and foods points to plant proteins as being more sustainable than animal-sourced ingredients. However, the nutritive quality of plant proteins is often less than that of animal proteins, while processing also affects the nutritional value of proteins. Incorporating the protein digestibility as a functional unit into the life cycle assessment, a ‘farm-to-faeces’ approach, provides a more actionable measurement to compare a set of ingredients, processes or final products. Conventionally and mildly fractionated pea protein ingredients were compared to a whey protein isolate acting as a reference of animal-sourced proteins. Processing influences both the digestibility and the overall environmental impact of the food. In some cases, processing might improve protein digestibility while different processes or conditions could reduce it. The digestibility of conventional ingredients such as a protein isolate (pea and whey) is reduced more strongly by processing than the mildly fractionated ingredients. Mild fractions always provide a more environmentally sustainable alternative to whey and pea protein isolates, in relation to both ingredient production and protein digestibility, demonstrating the usefulness of mild processing. In general, this study clearly demonstrates that processing and digestion should be included in a life cycle assessment study, to obtain a correct view of the impact of fulfilling our nutritional needs. •The digestibility of protein-rich ingredients is related to their processing history.•A novel ‘farm-to-faeces’ approach for LCA is demonstrated.•Based on digestibility, mild fractionation is still more sustainable than conventional.•Based on protein quality, pea ingredients have less impact than whey protein isolate.•Nutritional value should be included in an LCA of protein-rich ingredients.