3D printing of salmon fillet mimic: Imparting printability via high-pressure homogenization and post-printing texturization via transglutaminase

Abstract

Sustainability and environmental concerns towards animal protein production demands urgency in dietary shifts towards plant-based meat and seafood analogues. This study aimed to develop plant-protein based salmon mimics through three-dimensional (3D) printing of plant protein-based food inks coupled with post-printing transglutaminase (TGase) treatment. The simulant for the myosepta (white fat tissue) was developed as a pea protein emulsion with 5.5% protein content. To impart post-printing structural stability via high pressure homogenization (HPH), a minimum oil content of 30% was required. The myosepta simulant was then assembled with a red lentil protein emulsion which serves as the myomere simulant (orange muscle tissue) via 3D printing to form the salmon fillet mimic. Post-printing structural stability for the myomere simulant was conferred through gelation of its high protein content of 22%. Post-printing incubation at 55 °C substantially stimulated TGase to transform the emulsions from printable pastes to solids with texture profile comparable to real salmon fillet. Confocal imaging reflected the formation of porous protein networks in both simulants. In the texturized salmon mimic, the myosepta simulants with 5.5% protein content and 30–45% oil content achieved resemblance as a protein-stabilized oil droplet network with comparable mean oil droplet diameter d of below 1 μm. Whereas, the myomere simulant yielded a fibrous hierarchical structure resembling salmon myofiber and its constituent myofibrils through printing-induced alignment of protein aggregates. 3D printing with HPH ink plus post-printing texturization are critical contributors towards developing a plant-based mimic with macronutrient content, physicochemical properties and texture comparable to real salmon fillet.