Comparing nutritional and digestibility aspects of sustainable proteins using the INFOGEST digestion protocol

We studied several sustainable alternative protein concentrates and a whey protein concentrate as reference, to determine their protein composition, digestibility and quality using the harmonized INFOGEST static protocol. The proteins concentrates were analyzed to determine their conversion factor, degree of hydrolysis, true ileal digestibility, in vitro digestible indispensable amino acid score (IVDIAAS) and total absorbable amino acids and total essential amino acids. The results revealed that whey, blood plasma concentrate and yeast protein concentrate have a high mean true ileal indispensable amino acid in vitro digestibility (91.1–85.8%), closely followed by corn, pea, potato and proteins derived from lesser meal worms (ranging between 82.5 and 77.9%). Mycoprotein gave a much lower score in the mass balance, so that its other results could not be interpreted as being reliable. Whey, potato, blood plasma and yeast protein concentrates ranked highest in IVDIAAS (between 119 and 97.2), followed by lesser meal worm and pea (between 73.8 and 57.8) with corn protein concentrate having the lowest IVDIAAS due to underrepresentation of lysine. The method and data presented in this paper can form a start for further applying the INFOGEST in vitro digestion protocol to evaluate protein quality.