Enhancing the functional properties of whey
Research project: “Thermal inducement of secondary and aggregation structure of non-fractionated whey proteins and their influence on technofunctional properties”
Each year about 27m tons of milk are processed in Germany in 246 dairies and milk-processing enterprises. 30% of this volume is processed into cheese and cheese products while generating high amounts of rennet and acid whey as by-products. The whey’s composition and protein structure differs from company to company thus aggravating a standardization and uniform quality of the whey products.
Because of its protein content, whey has a high nutritional value; it also has superior potential foaming and gelling properties. These so-called technological-functional properties of untreated whey are, however, not optimal. An additional heat treatment to change the native structure of the proteins improves these properties which are so important for the industry. The precise reactions taking place during denaturation including any possible intermediate stages have not yet been systematically researched to the extent as to allow a selective adjustment of the functional properties of whey.
This research project was aimed at the investigation of the interrelation between the protein properties, or, more precisely, the initial structure of the whey proteins (secondary structure elements, aggregates) and the technological-functional properties of whey. Based on these findings, recommendations for the industry were developed on how to achieve the desired gelling and foaming properties of whey products.
The results from the comprehensive analysis show what impact treatment time, temperature and length as well as minor components have on the structure and technological-functional properties of whey. For example, it was found that treatment temperature and length have a significant influence on the foaming capacity with the temperature being the most decisive factor. Regarding their suitability for foaming and gelling, whey proteins require very different thermal conditions. Only a low introduction of thermal energy is required for optimal foaming, other than for gelling. Added to that, minor components such as calcium or lactose have a significant influence on the protein structure. All in all, it was found hat there is a very differentiated interrelation between the individual variables.
Based on the results of this study, the reactions taking place in the denaturation process were understood much better and interactions between the different components elucidated. Now, the results should be specifically applied to the respective situation in the individual company in order to optimize existing products and processes and to develop new products. Because the findings can be easily implemented into practice, SMEs can well benefit from them.
The specific adjustment of the functionality via heat treatment is an important contribution towards an improvement in the quality, standardization, stability and safety of whey products. This allows the company to create a higher value.
The present project was supported within the scope of the “program for promoting joint industrial research (IGF)” by the Federal Ministry for Economy and technology (via AiF) through the Research Association of the Food Industry (FEI). (AiF project no 15514 ZN, term 2008-2010).
Apart from the DIL as research institute, the Association of the German Dairy Industry, Berlin, participated in the project as industrial group.
If you would like to learn more about how you could benefit from the research results for the optimization of your products and processes, please contact at the DIL:
Dr. Ulf Strijowski
Telefon: +49 (0)54 31.183 – 224
Telefax: +49 (0)54 31.183 – 114
E-Mail: u.strijowski@dil-ev.de
Dr. Ute Bindrich
Head of research platform
Structure and functionality
Telefon: +49 (0)54 31.183 – 130
Telefax: +49 (0)54 31.183 – 114
E-Mail: u.bindrich@dil-ev.de
For further information, please refer to the project abstract:
Figure: Gel structure of whey proteins after different thermal treatment
