While meat is an established source of high-quality protein, limited data exists on plant-based meat analogues,
particularly regarding how specific production steps and extrusion conditions affect their protein quality and
ecological footprint. We used the Prot´eix soybean cultivar to produce dry soy protein intermediate products with
varying degrees of refinement and employed them to obtain meat analogues by high-moisture extrusion. As a
reference, a commercial soy protein concentrate was used to produce meat analogues by high- and low-moisture
extrusion. In vitro amino acid (AA) digestibility and in vitro DIAAS of intermediate products and extrudates were
assessed and compared to traditional soy-based foods and chicken breast. The meat analogues had high total
protein in vitro digestibility (>95 %) irrespective of extrusion type, energy input, and soybean variety. The
extrusion process substantially enhanced protein digestibility of mildly refined soy protein powders which had
low protein digestibility (<60 %). Consequently, meat analogues based on these raw materials showed the lowest
environmental footprint per kg quality-corrected protein - with a fourfold lower global warming potential than
chicken, compared to only a 17 % reduction observed for meat analogues based on soy protein isolate. In vitro
DIAAS values for all studied meat analogues ranged from 81 to 102 for children aged 0.5 to 3 years and were only
limited in sulfur-containing AA. Soy-based meat analogues were equally digestible as tofu and cooked chicken
breast, had similar protein quality as soymilk and tofu, and can be good to excellent protein sources for humans.