Plant-based and dairy-free are some of the common claims that consumers are looking out for these days on food packages. Frequently cited motivations for this shift in priority from a diet high in meat and dairy to a more conscious eating habit are concerns about animal welfare, health, and the environment. 

Seeking to capitalise on this growing trend, companies are increasingly trying to innovate and create foods that are not only tasty but also healthy and sustainable. However, such products are typically difficult to formulate. In particular, food technologists have to balance the three aspects of flavour, mouthfeel, and texture, and at the same time, ensure that the allergen requirements are met. 

The hurdles to overcome when developing plant-based meat are even greater. As the primary audience driving the demand for plant-based meat tend to be flexitarians–people who want to cut down on meat consumption without completely eliminating it from their diet–they mostly look out for meat alternatives that still look, taste, and smell like the meat products that they are familiar with. This is the benchmark that food companies developing plant-based meat must seek to achieve. 

Resembling conventional meat, there are two main categories of plant-based meat products. Plant-based whole-muscle meats are meant to take after conventional whole-muscle cuts such as fish fillets and steak, while plant-based restructured meats are developed to substitute ground and shredded meat products like nuggets and meatballs. Regardless of whole-muscle or restructured, plant-based meat products are formulated to surpass conventional meat not just in terms of nutritional value, but also texture, flavour, and preparation. 

To achieve the desired sensory properties of plant-based meat, extrusion is a common technique used. During extrusion, moisture, thermal energy, and mechanical energy are applied to transform protein mass into products with a similar appearance and texture to meat. These operational parameters, especially moisture content and temperature, can significantly affect the properties of the extrudate. Evidently, careful regulation of the extrusion process is an important first step in developing the ideal meat substitute. As a result, research focused on the operational parameters of the extrusion process is well-warranted. 

To this end, Tereos Asia has started a project to investigate the factors influencing the production of whole-muscle plant-based meat. For example, the research has found that high-moisture extrusion–ideally at 60% moisture–allows the development of a fibrous structure that is more characteristic of whole-muscle meat, while low-moisture extrusion results in a sponge-like texture more suitable for restructured meat alternatives. 

Other than moisture content, Tereos also looked at how the barrel temperature can affect the properties of the extrudate. Results showed that extrudate produced from higher barrel temperatures of 140-160°C appears to have a more distinct fibrous layer and does not break as easily when force is applied to it. It is also noted that the reduction of temperature in the cooling die stretches the flow profile of the protein mass, further developing the fibrous structure to give the extrudate a more meat-like appearance and texture. 

What is as important as process parameters when producing plant-based meat is the choice of protein used. Therefore, Tereos’ project also explored the functionalities of different proteins in meat alternatives. A popular plant-based protein for such application is wheat gluten. Wheat gluten is widely used in meat alternatives because of its viscoelastic and film-forming properties, as well as its high nutritional quality. Another up-and-coming protein that is rich in nutrients and with low allergenic potential is pea protein. 

Different types of proteins, when combined, can also affect the end-product differently than by themselves individually. For example, by varying the proportion of wheat gluten in the protein mix, it was found that increasing the amount of gluten aids in the formation of the fibrous structure. The addition of pea protein provides a smoother surface to the exterior of the extrudate, and a more distinct and regular layered appearance. An additional advantage of pea protein is it being able to complement wheat gluten with its high content of essential amino acid lysine, forming a complete protein. Through multiple trials, the team of experts at Tereos has come up with the optimised blend of protein for whole-muscle meat substitutes. Tereos is also actively exploring the potential of rice protein in this application and results so far have been promising. 

Through different studies, Tereos has identified the parameters key to the production of meat alternatives. These include moisture content, temperature, and protein composition. Varying these parameters can produce a variety of meat-alternative products including whole-muscle meats and restructured meats that is sure to appeal to modern consumers seeking sustainability and health. In this way, Tereos continues to be a key player in the development of plant-based meat alternatives, always aiming to create innovative and delicious products with its range of ingredients.