Laurids Pernice

Juiciness is a key quality attribute of meat analogues. However, a texture frequently perceived as dry remains a challenge in the development of plant-based alternatives. A promising approach is the targeted incorporation of water-rich gel phases that retain liquid during cooking and release it during consumption.

Hybrid Extrusion Printing (HEP) is an innovative co-extrusion process for the continuous production of multiphase meat analogues. In this process, the plasticized protein mass is divided into individual streams using a specially designed breaker plate system and combined with a separately supplied secondary stream. This creates macroscopic protein strands with a gel-forming binder phase arranged between them. This spatial structuring enables targeted modification of both product texture and liquid release.

However, the secondary phases investigated to date exhibit a trade-off between cooking stability and juiciness: while thermally gelling systems present challenges regarding their stability during cooking, the contribution of ionically gelling systems to juiciness during consumption has so far been limited. Thermal–ionic hybrid gels offer a potential solution. In these gel-in-gel systems, discrete micro- or macrogel particles are embedded in a continuous gel matrix, combining thermal and ionic gelation mechanisms. It remains unclear to what extent this approach can combine high cooking stability with targeted liquid release under mechanical loading.

Your work:

You will investigate the potential of thermal–ionic hybrid gels as a secondary phase for the HEP process. Your work will initially focus on preparing and characterizing the gel systems independently of extrusion. In particular, you will vary the gel particle size and the type of thermal gelling agent. Using optical, rheological, and mechanical analyses, you will examine the gel structure and its properties. In addition, you will investigate stability under thermal exposure, water-holding capacity, and liquid release under mechanical loading.

Based on these results, you will select suitable material systems and subsequently introduce them as a secondary stream into the HEP process. By examining the resulting extrudates, you will assess to what extent the properties of the isolated gels translate to the multiphase product.