Current Projects
Proteins from grasslands
The aim is to obtain proteins from grassland cuttings and other biomasses as part of an extended value chain to obtain platform chemicals or fibers. The proteins obtained are to be used as animal feed for non-ruminants (especially chicken and pigs), thus helping to reduce protein imports. The remaining biomass will be used as a base for fiber materials or for the production of platform chemicals. The demonstration of the process and the entire value chain will take place at the University of Hohenheim's Agricultural Sciences Experimental Station, "Unterer Lindenhof" site, and will serve to expand it into a competence center for the bioeconomy. Protein recovery is an indispensable part of the competence center to demonstrate the circular economy in the bioeconomy. The new plant section will be combined with the existing apparatus for the production of the platform chemical HMF (hydroxymethylfurfural), as a basis for biobased plastics. For the construction of the protein separation, process engineers led by Prof. Dr. R. Kohlus (Fg. 150c) and animal nutritionists led by Prof. Dr. M. Rodehutscord (Fg. 460a) are working together in close coordination.
Duration: 01.12.2020-31.11.2023
Participating institutions:
Department of Animal Nutrition (460a)
Department of Process Engineering and Food Powders (150c)
Completed Projects
Separation and drying of whey protein pectin-based fat replacer systems to modulate the textural properties of reduced-fat food formulations
The production volume of fat-free and low-fat foods, so-called "light" products, has increased continuously in Germany in recent years. Dairy products represent the largest group within this product category. In order to compensate for textural and sensory attributes compared to the high-fat variants, fat replacers are used in these products, with low-fat dairy products predominantly using whey protein-based fat replacer systems.
The aim of the research project is to build on the results of the previous project (AiF 17876N) to develop a scale-up capable technology for powdered fat replacer systems based on whey-protein-pectin complexes, with which these can be tailored to the respective use in dairy products and other foods such as confectionery and baked goods.
Participating institutions:
Department of Soft Matter Science and Dairy Technology (150e)
Department of Process Engineering and Food Powders (150c)
Sponsors: BMWi via AiF via FEI
FKZ: 21101 N
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Original project title: Abtrennen und Trocknung Molkenprotein-Pektin-basierter Fat-Replacer-Systeme zur Modulation der Textureigenschaften fettreduzierter Lebensmittelformulierungen
A good cleanability of production plants in the food industry, especially of the surfaces of the used components, contributes to meeting the high and increasing requirements of international and national standards and laws. Cleanability and durability are important not only in the direct food contact zone, but also in the splash area.
In this project interactions between the cleaning factors and the considered surfaces are examined. Surface characteristics are linked to cleaning efficiency to optimize the cleanability of food industry splash zone components. This knowledge is used to develop a method for measuring the cleaning success on the basis of the mechanical cleaning using brushes and sponges as well as falling film cleaning.
Next to the correlation of the surface characteristics with the cleaning efficiency, the focus also is on the change in the plant surface over time. Through the mechanical and chemical stress of daily cleaning in industry physical and chemical changes occur. With increasing surface aging, the properties and thus also the observed and analyzed characteristics of the surface change. The impact of these changes on cleaning and cleaning efficiency should be included in the correlation.
Aging is expected to depend on various factors and can be quantified by characteristic surface patterns.
Participating institutions:
Department of Process Engineering and Food Powders (150c)
Research department of Festo SE & Co. KG
Sponsors: Festo SE & Co. KG
Original project title: Reinigbarkeit von Oberflächen im Spritzbereich der Lebensmittelindustrie
Fluidized bed agglomeration is widely used in the field of food processing to improve the product characteristics of food powders, especially their dispersing and dosing capabilities. This is an investment and energy-intensive process. The integration of fluidized bed agglomeration into a spray drying process could significantly increase the energy efficiency of this process step.
Aim of this research project is the development of a modified spray drying process to produce agglomerated food powders. Based on the use of milk powder (skimmed and whole milk) as well as multi-component powders, it is intended to demonstrate that the process is suitable to significantly improve product quality. The integration should lead to better flowability, higher mechanical stability and improved dispersion behavior of the powder through optimized particle size distribution and stronger particle binding. Besides the higher process control stability and improved product qualities, the proposed procedure of integrating the fluidized bed agglomeration into the spray dryer in one unit operation is also more energy-efficient and economical than the individual processes, spray drying and downstream fluidized bed agglomeration.
Participating institutions: Department of Process Engineering and Food Powders (150c)
Sponsors: BMWi via AiF via FEI
FKZ: AiF20952 N
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Publications:
Frank, J., Raiber, T.V., Grotenhoff, L., Kohlus, R., 2023, Development of In-Line Measure-ment Techniques for Monitoring Powder Characteristics in a Multi-Stage Spray Drying Process. Processes, DOI: doi.org/10.3390/pr11071931 
Original project title: Mehrstufige Sprühtrocknung: Wirbelschicht-Sprühagglomeration zur kontrollierten Agglomeration von milchbasierten Mehrkomponenten-Systemen
The aim of the research project is to develop technologies for the pre-treatment of milk for the requirements of drying of dairy gel granules on the one hand and freezing of the granules on the other hand in order to create the prerequisites for the production of a storable intermediate. After reconstitution, the intermediate is to be used as a raw material for flexible cheese production. Furthermore, alternatives to the production of cheese from reconstituted skimmed milk powder and butterfat are to be examined in order to be able to evaluate their potential with regard to energy and water requirements.
Participating institutions:
Department of Soft Matter Science and Dairy Technology (150e)
Department of Process Engineering and Food Powders (150c)
Sponsors: BMWi via AiF via FEI
FKZ: AiF 21265 N
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Publications:
Frank, J., Schlitter, M., Hinrichs, J. & Kohlus, R., 2023, Fluidized bed drying of dairy gel granules supported by inline monitoring of the water content. Dry. Technol., DOI: 10.1080/07373937.2023.2216774
Schmidt, F., Graf, B., Hinrichs, J. & Kern, C., 2022, Continuous microwave-assisted extrusion for high moisture texturized foods: A feasibility study. Inn. Food Sci. Emerg. Technol. 78, 103020, DOI: 10.1016/j.ifset.2022.103020 (2022).
Original project title: Lagerfähige Milchgelgranulate als neuer Grundstoff für das Herstellen von Käseprodukten
Herbs are seasonal products with a very limited shelf life. Good storability of the raw materials is usually achieved by drying. However, during this and the subsequent grinding, a change in the aroma profile and a loss of aroma intensity can be observed. In addition, significant off-flavors can arise. These aroma changes or losses could be reduced by changing the process and using short-term drying. The aim of the research project is the exemplary improvement of the drying process of herbs and spices with regard to their aroma content in comparison to the freeze-dried product (using the example of basil) and compared to the fresh product (using the example of ginger).
Participating institutions:
Dept. Process Engineering and Food Powders (150c)
Dept. Flavor Chemistry (150h)
Sponsors: BMW via AiF via FEI
FKZ: AiF 20752 N
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Publications:
Liang, J., Shalaby, N., Rigling, M., Wagner, T., Heimbach, J., Fries, A., Kohlus, R. & Zhang, Y., 2022, Characterization of hay-like off-odor in basil samples after various processing and strategies for reducing the off-odor. Food Res. Intern. 162, Part B, 112080, DOI: 10.1016/j.foodres.2022.112080
Liang, J., Stoeppelmann, F., Schoenbach, J., Rigling, M., Nedele, A., Zhang, Y., Hannemann, L., Hua, N., Heimbach, J., Kohlus, R., Zhang, Y., 2023, Influence of peeling on volatile and non-volatile compounds responsible for aroma, sensory and nutrition in ginger (Zingiber officinale). Food Chemistry 419, DOI: 10.1016/j.foodchem.2023.136036
Original project title: Erhalt des Aromaprofiles von Kräutern und Gewürzen mittels Kurzzeittrocknung am Beispiel von Basilikum und Ingwer
Spray drying is one of the most important industrial drying techniques. With this, large volumes with high energy requirements are processed. About two thirds of this energy is tied up in the vaporization enthalpy of the evaporating water. The use of superheated steam enables the "recovery" of the evaporation enthalpy through steam condensation and achieves a product quality specific to the process through atomization in steam atmosphere. The aim of the research project is to optimize the energy requirement for spray drying food by using the heat of condensation during spray drying with superheated steam. In addition to energy saving, there are two product-specific issues that need to be investigated: the temperature load and the particle structure effects.
Sponsors: BMWI via AiF via FEI
FKZ: AiF 45 EWN
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Publications:
Linke, T., Kirsch, R., Kohlus, R., 2021, A barometric approach for high temperatrue water desorption istotherm determination. LWT, 140, 110750, DOI: 10.1016/jlwt.202.110750
Linke, T., Happe, J., Kohlus, R., 2020, Laboratory-scale superheated steam spray drying of food and dairy products. Dry.Tech. DOI: 10.1080/07373937.2020.1870127
Original project title: Energieeffiziente Sprühtrocknung von Lebensmitteln mit Heißdampf: Charakterisierung und Optimierung limitierender Einflussfaktoren
The extrusion of highly concentrated suspensions (pastes) is a common processing operation in (food) industry. To optimize the extrusion process, information regarding the rheological behaviour of the paste is required. Rheological characterization is nonetheless difficult, since flow regions co-exist, creating a complex flow profile.The aim of this research is to measure and describe paste flow as a function of its constituents, in relation to the different flow regions.
The solubility of dried foods, especially spray-dried dairy-based powders, is critical to their functionality and marketability. Dairy-based powders offer decisive advantages over the liquid form regarding storage and transport and are used in a wide range of applications. The powders are dissolved before use, with the products sometimes differing significantly in their rehydration behavior. The causes of a fluctuating or poor solubility are complex: the interaction of the influencing factors and their control have not yet been sufficiently clarified. It would therefore be of great benefit for companies producing dairy powders to know how relevant product characteristics, e.g. size and shape of the particles, surface quality and internal structure, influence the rehydration behavior in order to be able to produce the appropriate powder qualities and thus better position themselves in the narrow market. The aim of the research project is therefore the development of a standard measurement technique for characterizing the dissolution behavior of dairy-based powders. The measurement method is intended to depict the parameters of specific energy input, temperature and rehydration time and can be used in product development, quality control and product specification.
Participating institutions:
Department of Process Engineering and Food Powders (150c)
HS Anhalt, Department Food Process Engineering/Dairy technology
Sponsors: BMWi via AiF via FEI
FKZ: AIF 19360 BG
Short project report (in German)
The final report is available to the interested public at the research department (in German).
Publications:
Schulnies, Frank; Teichmann, Heike; Kohlus, Reinhard; Kleinschmidt, Sebastian; Kleinschmidt, Thomas (2022): Photometric extinction measurements to study dissolution kinetic of skim milk powder. In: International Dairy Journal 130, S. 105210. DOI: 10.1016/j.idairyj.2021.105210.
Original project title: Anwendungsspezifische Charakterisierung und Optimierung der Rehydratation von sprühgetrockneten Milchprodukten basierend auf physikalisch-mechanistischer Modellbildung
Process management and quality optimization of high-quality products made from microalgae ingredients
Microalgae do have a vast amount of high quality ingredients that offer substantial nutritional potential, but are so far rarely used in food. In this project, the suitability of proteins and lipids from microalgae as a food ingredient will be evaluated. The main objective is to partially or fully replace animal protein and fat, while preserving the familiar food characteristics.
Proteins and lipid fractions from microalgae will be examined for technofunctional properties (e.g. emulsification and gelation), mixing behavior with conventional food ingredients (protein, fats and carbohydrates from plant and animal sources), and their behavior during the manufacturing processes. Subsequently, these properties will be transferred to possible applications in food systems and specific quality parameters will be evaluated and compared with conventional foods. Main products are lipid and fat powders that can serve as a storable, readily manageable form of ω3-, or ω6-fatty acids and protein powders as alternative for conventional food proteins.
Project duration: 01.04.2015-31.07.2018
FKZ: MWK 7533-120-5-87
Laufzeit: 2015 – 2018
Project duration: 01.01.2014 – 31.12.2017
FKZ: (EU FP7-SME 613968)