How plant-based meat and seafood are processed

Authors: McHugh, Tara; Avena-Bustillos, Roberto

Submitted to: Food Technology
Publication Type: Trade Journal
Publication Acceptance Date: 9/19/2019
Publication Date: 10/1/2019
Citation: McHugh, T.H., Avena Bustillos, R.D. 2019. How plant-based meat and seafood are processed. Food Technology. 73(10):83-84,87.

Interpretive Summary: Due to a change in consumer's dietary habits towards a vegetarian diet and awareness of our overexploitation of natural resources due to the increase of world population, products from plant proteins have been increasingly developed over the past years mimicking the fibrous texture of meat, poultry and seafoods. These foods can be created from plant-based proteins by extrusion cooking, by solidifying proteins with a mixture of hydrocolloids and divalent cations, or by using the newly emerging shear cell technology. Among others, high moisture extrusion processing so called protein fibration technology can be applied to impart a specific texture to plant proteins such as wheat gluten, soy, or pea protein. These textured products can be used as a high-protein ingredient (e.g., meat analog product or meat extender) in a wide variety of ready to eat products.

Technical Abstract: During high moisture extrusion processing, proteins undergo thermal and mechanical stresses by heating of the barrel and shearing of the screws. As a result of this thermo-mechanical treatment, proteins native structures are altered by denaturation and a change in molecular structure leading to the formation of soluble and/or insoluble aggregates. By attaching a long cooling die to the end of the extruder, proteins are assumed to realign in flow direction forming an anisotropic protein network. Based on this general understanding of the process, it can be expected that different final product characteristics can be achieved by altering process conditions during high moisture extrusion processing. Recently, wet texturization has emerged using twin-screw extrusion in a combination of a series of chemical and physical processes (thermomechanical cooking and die fibration) to produce a more fibrous structure and meat-like texture of the resulting products. An appropriate pre-treatment allows the use of a larger spectrum of proteins and other ingredients such as starches, fibers and additives. High-moisture texturized proteins are usually processed and packaged in wet condition (pouches, cans or frozen). Due to the more complex technological processes, the extruded mass is subject to an additional treatment in the so-called forming units (additional plasticizing devices), where it is chilled, unified and molded into strips or patties. The actual trend toward flexitarian, vegan and vegetarian diets is influencing the use of plant-based proteins as meat and seafood substitutes. While most meat substitutes still are based on soy or wheat gluten protein, new meat analogues are emerging as well with alternative proteins, binders, flavor enhancers, and natural colors. An important area of opportunity for meat analogues is targeting meat eaters as much as vegetarians. Many eaters may turn to meat and seafood analogues if the products are right in texture, flavor, shape and appearance. New research and development then will need to answer and solve the interactions of flavor and colorants with plant-based proteins and how water bounds with plant-based proteins to allow an increase of juiciness and freshness of new plant-based protein meat and seafood analogues.