Development of a protein food based on texturized wheat proteins, with high protein digestibility and improved lysine content

Abstract

The development of plant-based protein foods may facilitate the decrease in animal product consumption in western countries. Wheat proteins, as a starch coproduct, are available in large amounts and are good candidates for this development. We investigated the effect of a new texturing process on wheat protein digestibility and implemented strategies aimed at enhancing the lysine content of the product developed. Protein true ileal digestibility (TID) was determined in minipigs. In a preliminary experiment, the TID of wheat protein (WP), texturized wheat protein (TWP), TWP enriched with free lysine (TWP-L), or with chickpea flour (TWP-CP) was measured and compared to beef meat proteins. In the main experiment, minipigs (n = 6) were fed a dish (blanquette type) containing 40 g of protein in the form of TWP-CP, TWP-CP enriched with free lysine TWP-CP+L, chicken filet, or texturized soy, together with quinoa (18.5 g of protein) in order to improve meal supply of lysine. Wheat protein texturing did not affect total amino acid TID (96.8 % for TWP vs 95.3 % for WP), which was not different from that of beef meat (95.8 %). Chickpea addition did not affect protein TID (96.5 % for TWP-CP vs 96.8 % for TWP). The Digestible Indispensable Amino Acid Score for adults of the dish combining TWP-CP+L with quinoa was 91, whereas it was 110 and 111 for the dishes containing chicken filet or texturized soy. The above results show that, by optimizing lysine content through the formulation of the product, wheat protein texturization can enable the development of protein-rich products of nutritional quality compatible with quality protein intake in the context of a complete meal.

Keywords: DIAAS; Human nutrition; Protein digestibility; Wheat proteins.