Experimental study of conveying food suspensions with pumps by means of different model systems

Essential quality aspects are the typical texture and visual appearance of food. For liquid foods with particles, such as stews or fruit preparations, the integrity of the particles in the liquid phase is a key quality criteria.

Therefore pumping suspensions is a critical process step, which is especially crucial for these characteristic properties of the particles. A high quality of the suspension can be ensured by choosing suitable pump types. Special attention should be paid to the pump components in contact with the product and the process factors. A food producer relies mostly on his own experience finding the best suited pumps and settings for the respective food suspension. Possible improvement potentials cannot be exploited due to the lack of objective examinations.

Accordingly, the presented PhD project focuses on analysing the quality-reducing influences of various pumps on different food suspensions. The main objective is to identify and quantify the influencing factors regarding the destructive effect of the pumping process on the particles. Recommendations are given for the adaptation of pumps, pump components and pump settings for specific food suspensions.

An important influencing factor is the texture of the particles in the food suspension. Investigations on the influence of the texture in pumping tests are problematic, due to the difficult standardization of the structural characteristics of the food particles, as well as the shape and size. For this reason, the texture-related properties of the food particles are modelled for the pump tests with gels based on hydrocolloids. The developed gels represent the food particles - especially the texture-related properties in approximation - during the pump tests. Therefore, an additional aim of this work is the development of model particles based on hydrocolloids, which have the same texture properties during pumping of food particles.

responsible : Christian Schmitt (M.Sc.)