High quality whey proteins for food
The production of cheese and casein produces large quantities of whey. 81 million tons per year come together with the aqueous residue in the EU alone. Approximately 40 percent of it is already processed via filtration to whey concentrate and further to various whey products. Most of the whey, however, remains unused. In addition to milk sugar and minerals, whey mainly contains valuable milk proteins. "As natural binders and emulsifiers, proteins could be used in the food industry," Dr. Ana Lucia Vasquez, who directs the project at the IGB, the economic potential and goal of the new project. »They are also suitable for functional nutritional supplements, eg. In baby food or as a source of protein in athletic drinks, "says the expert.
For these applications, however, the proteins from the whey must first be purified. There are already approaches to extract specific milk proteins, for example the antithrombogenic casein macropeptide, from whey. However, the chromatographic methods used are complex and are not suitable for high throughput. Whey concentrate is obtained via ultrafiltration. In this process, the small molecules in whey - water, minerals, and lactose - pass through the pores of a membrane while proteins are retained. However, the proteins are only concentrated in their entirety, but not separated according to functional protein fractions. In addition, residues are quickly deposited on the membranes. This fouling worsens the filtration performance, so that the membranes have to be cleaned frequently.
In order to selectively enrich proteins and add them to foods according to their nutritional or technological-functional properties, the Whey2Food project aims to further develop an electromembrane process developed at the University of Hohenheim. “The process combines pressure filtration through a porous membrane with an electric field. The proteins are not only separated according to their size, but also according to their charge, ”explains Vasquez. Compared to ultrafiltration, this increases the yield and reduces the cleaning effort. "In preliminary tests, we were able to show that the electromembrane process can be used to separate peptides or protein fragments such as casein macropeptides from two other typical whey proteins, alpha-lactalbumin and beta-lactoglobulin," says Professor Dr.-Ing. Jörg Hinrichs from the Institute for Food Science and Biotechnology at the University of Hohenheim.
Now the researchers want to optimize the process for industrially relevant quantities and according to the hygiene and cleaning standards prescribed for food companies. "We will then use an automated pilot system to test the process in continuous operation at our project partners Rovita and Schwarzwaldmilch under real conditions," says Vasquez. Another advantage of the electromembrane process is reduced fouling. This reduces operating costs and energy consumption.
The project “Whey2Food - Enhanced protein fractionation from protein sources for their use in special food applications” has been running since 1. November 2013 funded in the 7th Research Framework Program of the EU (Grant Agreement No. 605807). The German research partners Fraunhofer IGB and the University of Hohenheim as well as the Belgian VITO are developing the process together with a European consortium of companies.
Source: Stuttgart [IGB]
