Texturization of plant protein-based meat alternatives: Processing, base proteins, and other constructional ingredients

Recent awareness related to health concerns and environmental sustainability issues have led to changes in consumer preference toward plant-based proteins and the related market has been booming with growing investments and new plant-based alternatives. However, this relatively new market needs to make improvements in the quality of products (e.g., texture, flavor, and color) to match those of meat and cheese products. Specifically, forming an anisotropic structure to have similar textural properties has become one of the biggest challenges. To enable this, advanced and novel technologies (e.g., extrusion, shear-structuring, 3D printing, electrospinning, and freeze-structuring), as well as functional ingredients (e.g., binding/viscoelastic agents, crosslinkers), have been introduced to provide meat-like textures to analogue products. Even though the texturerelated problems of meat alternatives have been resolved to some extent with use of methylcellulose or wheat gluten, there is still a search for natural and chemically-free ingredients to align with a desire for "clean label" products. Here, we postulate that corn zein, and perhaps other similar viscoelastic plant proteins, can be used to provide the necessary textural properties to plant-based meat analogues instead of currently used ingredients. In this review, a comprehensive assessment of state-of-the-field processing techniques as well as functional ingredients (both already available and potential ones) necessary to provide the desired characteristics to plantbased protein products is given.