Multi-criteria assessment of pea protein quality in rats: a comparison between casein, gluten and pea protein alone or supplemented with methionine

Abstract

The objective of this study was to assess the nutritional quality of pea protein isolate in rats and to evaluate the impact of methionine (Met) supplementation. Several protein diets were studied: pea protein, casein, gluten, pea protein-gluten combination and pea protein supplemented with Met. Study 1: Young male Wistar rats (n = 8/group) were fed the test diets ad libitum for 28 days. The Protein Efficiency Ratio (PER) was measured. Study 2: Adult male Wistar rats (n = 9/group) were fed the test diets for 10 days. A protein-free diet group was used to determine nitrogen (N) endogenous losses. The rats were placed in metabolic cages for 3 days to assess N balance, true fecal N digestibility, and to calculate the Protein Digestible-Corrected Amino Acid Score (PDCAAS). They were then given a calibrated meal and euthanized 6 hours later for collection of digestive contents. The true cecal amino acid (AA) digestibility was determined and the Digestible Indispensable Amino Acid Score (DIAAS) was calculated. Met supplementation increased the PER of pea protein (2.52 vs. 1.14, P < 0.001) up to the PER of casein (2.55). Mean true cecal AA digestibility was 94% for pea protein. The DIAAS was 0.88 for pea protein and 1.10 with Met supplementation, 1.29 for casein and 0.25 for gluten. Pea protein was highly digestible in rats under our experimental conditions, and Met supplementation enabled generation of a mixture that had a protein quality that was not different from that of casein.

Pea Proteins Have Anabolic Effects Comparable to Milk Proteins on Whole Body Protein Retention and Muscle Protein Metabolism in Old Rats

“…First, the apparent and true digestibilities of pea proteins were in the same range of values of the other proteins. Recent studies have reported that pea protein is highly digestible in rats [18,23]. However, this work represents one of the first studies to show that pea protein is also highly digestible in old rats.…”

“…However, this work represents one of the first studies to show that pea protein is also highly digestible in old rats. It has been suggested that the digestibility of plant proteins is impaired due to the presence of both anti-nutritional factors and indigestible fractions in their sequence [23]. However, the pea protein used here was a protein isolate, and protein isolates are generally well-digested [24].…”

Textured wheat and pea proteins for meat alternative applications

“…Pea protein isolate has a reported PER of 1.14, which increased to 2.52 upon supplementation with methionine to the same amount present in casein, which has a PER of 2.55. PDCAAS, calculated using true fecal nitrogen digestibility values, and DIAAS, calculated using true cecal amino acid digestibility values, for pea protein isolate are 1.02 and 0.88, respectively (Guillin et al, 2021). DIAAS values determined in pigs instead of rats showed that proteins from animal (dairy) source (1.0-1.2) exhibited higher values than proteins from soy, pea, or wheat (0.45-0.89) (Mathai et al, 2017).…”

Safety of mung bean protein as a novel food pursuant to Regulation (EU) 2015/2283

“…The Panel notes that mung bean protein is well digestible (Moughan et al., 2012 ; Rutherfurd et al., 2012 , 2015 ; Devi et al., 2018 ; Kashyap et al., 2019 ; Shivakumar et al., 2019 ). It provides sufficient amounts of most essential amino acids but only limited amounts of sulfur‐containing amino acids, and for this reason, the PDCAAS of the NF is lower than that for other legume proteins (Hughes et al., 2011 ; Guillin et al., 2021 ; Rutherfurd et al., 2015 ). Based on the highest (max.…”