Influence of different amino acid scoring patterns on the protein quality of field peas

Abstract

Pea (Pisum sativum L.) is a nutritious pulse crop and a significant plant-based protein source. Its amino acid composition and protein digestibility influence its nutritional quality. Although different guidelines for protein content claims exist in North America, recommended patterns by FAO/WHO can estimate protein quality for dietary assessment. This study’s primary objective is to examine how adopting the new FAO/WHO recommendations affects the protein quality and protein content claims of field peas, using in vitro methods, and to assess the potential impact on consumer food choices. This work evaluated the amino acid score (AAS) and in vitro protein digestibility (IVPD) to assess pea protein quality. The effect of different amino acid scoring patterns recommended by FAO/WHO (1991, 2013) on AAS was estimated. The in vitro–protein digestibility corrected amino acid score (IV–PDCAAS) and in vitro–digestible indispensable amino acid score (IV–DIAAS) were calculated. Overall, pea protein quality varies with different amino acid scoring patterns. Sulfur amino acids (SAA) were the first-limiting amino acid. The IVPD was 80.6 to 88.6%, the mean IV–PDCAAS was 73.0%, and IV–DIAAS was up to 87.6%. Using the PDCAAS interpretation, all IV–PDCAAS samples qualified for a “good source of protein” claim. For DIAAS interpretation, some IV–DIAAS samples did not meet this claim due to the arbitrary cut-off of 75%. Therefore, the criteria for making protein content claims on food proteins should be reevaluated. This study highlighted significant variations in amino acid nutritional requirements across different life stages, impacting the protein quality assessment of field peas and, consequently, protein content claims, with implications for dietary guidelines and food labeling regulations.