Focus on freezing, extrusion and fermentation

The scale of the food industry is larger than our domestic kitchens, but the processes are often the same. Food is processed by removing parts, such as husk and peel. At home, potatoes are peeled before they are boiled and, in the milling industry, the husk is removed from oats before they are rolled into groats. The mill then produces flours with different compositions and properties that are adapted for different products.

The Foundation is funding a project at RISE that aims to increase understanding of how components in flour contribute to the properties of bread. Flour is broken down into its constituent parts, such as starch, protein and fibre, and then recreated using compositions that are evaluated through baking tests. Food is also processed so that it can be preserved for a long time. Freezing is a common technique that can be quite complicated. For example, boiled potatoes decline in quality when frozen and thawed. Industrially, similar challenges exist with products that decrease in volume when frozen, which can lead to consumers to perceive that they are getting less for their money. Recently, our foundation funded a project that will study how volume losses can be reduced during the freezing of bake-off products.

Another way to preserve food is fermentation, which lowers pH and thus extends products’ shelf life. Fermentation can also improve the taste and nutritional value of a product. Dutch researchers are currently studying how different microorganisms can improve the taste of peas and faba beans through fermentation. In another project, researchers at Chalmers University of Technology are investigating whether the content of phytic acid in yellow peas can be reduced, as this substance interferes with the absorption of iron in the body. In many cases, the purpose of food processing is to create pleasant textures and flavours. Breakfast cereals and meat substitutes are examples of products made using extrusion, a process where f lour from cereals or legumes and water is kneaded at a high temperature and pressure, before being pressed through a nozzle into the desired shape and texture. This is how breakfast cereals are puffed and meat-like fibre textures are made in plant-based burgers. Researchers at RISE have studied exactly how these meat-like fibre structures are formed. This knowledge is necessary for developing innovative products from legumes. 

Food processing and preservation is a complex area, where detailed knowledge and understanding are needed to harness the strengths of the ingredients. Research on food processing will remain vital.