Postprandial amino acid response after the ingestion of pea protein, milk protein, casein and a casein–pea blend, in healthy older adults

Figures & data

Figure 1. Study design and protocol.

Table 1. Subject characteristics.

N (male/female)	12 (6/6)
Age (years)	72.3 ± 3.4
Body weight (kg)	74.0 ± 11.2
BMI (kg/m^2)	25.3 ± 2.9
Fasting glucose (mmol/L)	5.2 ± 0.46

Values are mean ± SD.

Table 2. Macronutrient composition protein drinks.

	Milk protein (81.5% protein)^b	Micellar casein (81.5% protein)^b	Pea protein (84% protein)^b	Casein/Pea blend (79% protein)^b
Supplement (g)	24.5	24.5	23.8	25.3
Protein (g)	20	20	20	20
Carbohydrates (g)	1.3	1.0	N/A	1.1
Fat (g)	0.5	0.4	0.7	0.8
Other^a (g)	2.7	3.0	1.2	3.5
Water	250	250	250	250

For AA composition, see Supplementary Table 1.

^a E.g. ash, moisture; N/A: not available.

^b Protein content determined with Kjeldahl’s method.

Figure 2. Plasma AA response for all four protein conditions; AA totals (TAA), essential AA (TEAA) and branched-chain AA (BCAA), respectively. Mean ± SD, for clarity only SD for milk protein (positive) and micellar casein (negative SD bar) are given.

Figure 3. Plasma AA response for all four protein conditions; leucine, arginine, methionine and lysine, respectively. Mean ± SD, for clarity only SD for the highest curve (positive) and lowest curve (negative SD bar) are given.

Figure 4. Plasma insulin response for all four protein conditions. Mean ± SD; for clarity only SD for pea (positive) and casein (negative SD bar) are given.

Figure 5. Fitted area under the curve (AUC, µM·min) and peak height (µmol/L), corrected for baseline, and time to max (Time2Max, min) values for each individual amino acid for all four protein conditions (average + CI). Asp, Cys, Glu and Gly were not considered due to too much missing values in curve fitting as blood levels were very low and/or showed no clear response; *significant different from pea (p < .05, with multiple-testing correction (Dunnett)).

Figure 6. Fitted area under the curve (AUC, µM·min) and peak height (µmol/L), corrected for baseline, and time to max height (Time2Max, min) values for amino acid totals for all four protein conditions (average + CI). *Significant different from pea.