Effect of protein texturization on amino acids and protein in vitro bioaccessibility of pea and rice protein†

Abstract

The growing demand for vegetable proteins, driven by population increase and interest in sustainable protein-rich diets, has generated a focus on the use of legumes and cereals as protein sources for the production of meat analogues due to their complementary nutritional profile and lower environmental impact. However, the analogues should not only imitate the nutritional profile of meat, but their texture is also important for good commercialization. One of the processes used to improve these properties is protein texturization by thermoextrusion, which could modify the availability and digestibility of amino acids. Thus, the objective of this work is to evaluate the in vitro bioaccessibility of proteins and amino acids from pea and rice protein isolates (I) and texturized proteins (T). Proteins from pea (PP), rice (RP) and a 50 : 50 mixture (PRP) were processed by extrusion, evaluating the effects on digestibility and bioaccessibility of essential (EAA) and non-essential (NEAA) amino acids. The results showed higher in vitro digestibility and bioaccessibility of NEAA of texturized proteins compared to isolated proteins, although this effect is not significant for PP. However, texturization significantly reduced the bioaccessibility of some EAA such as lysine. Rice protein showed greater stability during the extrusion process, maintaining a more balanced amino acid profile. Texturization can therefore be a useful tool to improve the functionality of vegetable proteins, but it is necessary to optimize the process to minimize nutritional losses.