Food Innovation In Your Kitchen
Researchers develop method to turn legumes into meat-like texture, reducing food waste
Introduction To Food Innovation
Food production often involves breaking down agricultural raw materials into their individual constituents, such as proteins, starches, and fats, and then reassembling these building blocks into specific products. However, this process can lead to the loss of dietary fibers, vitamins, and minerals in the finished product. To reduce food waste and retain as much of a food's nutritional value as possible, researchers at ETH Zurich, led by Professor Patrick Rühs, are exploring ways to use harvested crops in their whole form wherever possible.
The research group has made a significant breakthrough in developing a method to turn whole peas, beans, or lentils into a product with a fibrous structure that is similar to meat or fish. This texture is achieved through a process called "freeze-structuring," which involves soaking and blending the legumes, heating the puree, and then freezing it in a targeted manner to create a directional, fibrous structure.
Understanding Freeze-Structuring
The freeze-structuring method is surprisingly simple and can even be carried out in a household kitchen. The process involves soaking the legumes and blending them finely to create a uniform distribution of starch, proteins, and cell wall fragments. The puree is then heated for 30 minutes at 90°C, causing the starch to gelatinize together with the other constituents, and the puree becomes a gel.
The gel is then frozen from one side in a targeted manner using a mold that is insulated on all sides except one. This causes ice crystals to form in parallel and inward from the uninsulated side, squeezing and compressing the legume puree into thin parallel layers. When the gel is thawed, the ice melts, but the directional, fibrous structure remains intact.
Testing Different Legumes
The researchers tested a variety of different types of beans, peas, and lentils and were able to create a directional fibrous structure with all of them. According to Andrea Bach, a doctoral student in Rühs's group, "Our method works with legume species that together account for 96% of legume production worldwide." However, the researchers also identified certain differences in the textures produced by different legumes.
The fibers were particularly strong and stable with red and black lentils, as well as with mung beans, while they were slightly softer with soybeans or black beans. The final strength of the product also depended on how much the legumes were heated and frozen. The researchers used a scanning electron microscope to examine the structure of the freeze-structured legume purée, which revealed a complex network of fibers and cell wall fragments.
Real-World Implications
The development of the freeze-structuring method has significant implications for the food industry. By creating a product with a meat-like texture from whole legumes, the researchers may be able to reduce food waste and retain more of the nutritional value of the legumes. This could lead to the development of new, sustainable food products that are high in protein and fiber and have a lower environmental impact than traditional meat products.
The method could also be used to create a variety of different textures and flavors, depending on the type of legume used and the processing conditions. According to Professor Rühs, "During chewing, a directional, fibrous structure provides a distinctive bite that is familiar to—and enjoyed by—many people from meat or fish." The researchers hope that their method will inspire the development of new, innovative food products that are both sustainable and appealing to consumers.
Future Outlook
The development of the freeze-structuring method is an exciting breakthrough in the field of food science. The researchers at ETH Zurich are continuing to refine their method and explore its potential applications in the food industry. With the growing demand for sustainable and nutritious food products, the development of new technologies like freeze-structuring could play a key role in reducing food waste and promoting more sustainable food systems.
As the world's population continues to grow, the need for innovative and sustainable food solutions will become increasingly important. The work of researchers like Professor Rühs and his team at ETH Zurich is helping to pave the way for a more sustainable food future, and their discoveries have the potential to make a significant impact on the way we produce and consume food.
Sources
This is an original synthesis by Qivorane based on reporting from the outlets below.