STRING – Extrusion of dairy proteins into novel anisotropic foods

Over the past decade, the development of novel structured products has emerged as the most promising strategy to decrease meat consumption or result in novel textural attributes. Extrusion of particulate food ingredients may lead to novel structure formation by inducing new intermolecular interactions and crosslinks between the matrix constituents. This project aims to develop novel food structures with very different textural behaviors and food prototypes with a broad range of textures from a thermoplastic mass consisting of dairy proteins and plant polysaccharides.

By: Grith Mortensen

Twin-screw extrusion, using low or high moisture, is the most used commercial technique to transform materials into fibrous products. Even though milk proteins are versatile and have very good technological properties, studies regarding the extrusion of dairy proteins are limited. It is hypothesized that dairy proteins, including protein concentrates in liquid and powder form, can act as a scaffold for the formation of multi-phase structures containing also starch.

In this project the researchers will investigate, the behavior of bovine milk protein concentrate (in liquid or powder form) under different pilot-scale extrusion conditions in mixtures with different starches varying in colloidal behavior (e.g., pea starch, potato starch, pregelatinized maize starch). Extrusion trials will be conducted using lab and pilot plant scale extruders. The samples showing commercially acceptable textural and cooking properties will be selected for sensor analysis. Furthermore, the project will provide a better understanding of the molecular and colloidal mechanisms responsible for structure formation when applying high moisture extrusion.

The current research combines previous work on biopolymer (polysaccharides and proteins) biochemistry, thermomechanical processing of plant-based foods and advanced food nanotechnology. The overall ambition is to create the scientific foundation for the development of meat-like textures based on dairy and plant ingredients. Particularly, this project will unlock the utilization of by-products from the dairy industry (including those in liquid form) to manufacture novel foods.