Tailoring anisotropy and tenderness in high-moisture meat analogues by controlling porosity through gas injection

Meat alternatives are a sustainable food option increasingly becoming a regular part of many consumers' diets. One major challenge that still exists in producing plant-based meat alternatives is replicating the wide variety textural attributes of the different meat-based products on the market. Gas-assisted high moisture extrusion might be a promising approach to tailor the structure and anisotropy of extruded plant proteins. This study investigated the impact of a gas-assisted high-moisture extrusion cooking technique on the anisotropy and textural properties by modifying the porosity by gas injection. Nitrogen gas injection was implemented at barrel sections 2, 3 and 4 (out of 7) with different gas volume rates (0, 5, 10, 20, 40 ml/min). Gas incorporation creates porous structures with pore sizes of 18.18–73.93 μm and 21.00–77.29 μm when injected in the first and second halves of the barrel, respectively, at 0–40 ml/min. This process reduces density by up to 14.87%, enhances lightness, and imparts a fibrous appearance. Additionally, it lowers Warner-Bratzler shear force, hardness, and chewiness, improving extrudate tenderness as gas volume increases and the anisotropy index rose from 1.41 to a maximum of 1.74, reached with a gas injection rate of 5 ml/min in the first half of the barrel. Overall, modifying the porous structure can be utilized to tailor the structural attributes of high moisture extrudates with potential more desirable textural attributes.