Cheese manufacturers can use animal-free proteins in their regular production process by making micelles from casein proteins derived from precision fermentation. Photo Shutterstock. Laurens Antuma (Food Process Engineering) is to obtain his PhD in the artificial forming of micelles from casein proteins obtained from precision fermentation. These micelles are needed to produce cheese, are they not?
‘Precision fermentation (a process in which micro-organisms are genetically modified to produce, for example, lactoproteins), enables us to make casein, the key protein used in the production of cheese. That process yields individual proteins, while cheese manufacturers use protein in the form of micelles, or protein in a ball-like shape, to make the hard cheeses with which we are familiar’, Antuma explains. He studied how to make micelles from these individual animal-free proteins, so that producers can use them in their regular production process and, ultimately, make animal-free dairy products.
Antuma compares micelles to tennis balls. ‘Dairy milk contains four key casein protein varieties, which all differ slightly, but which we can all reproduce through precision fermentation. Three proteins react with calcium phosphate crystals, forming the internal structure of the spheres, while the fourth latches onto the exterior, forming a stable ‘fuzzy’ ball: the micelle.’ The fuzz is removed from the micelle by an enzyme in the cheese-making process, after which the spheres coagulate. ‘The resulting coagulated mass is curd, a semi-finished product of cheese.’
Scalable
‘You could simply toss these different types of casein together with calcium and phosphate ions in water to obtain micelles’, Antuma explains. ‘But that would mean you have no control over the process.’ Hence, he took a more scientific approach. We started with water and added the four casein types in different ratios, along with varying amounts of calcium phosphate, to reconstruct the micelles found in dairy milk. That works fine on a small scale in the lab, but to reproduce this within the food processing industry requires more efficient methods.’
The power of precision fermentation lies in our ability to reproduce the key resource in the production of cheese with precisely the same proteins the cow makes
Laurens Antuma, PhD candidate Food Process Engineering
He made a scalable testing setup with membranes to make the methods more relevant to the industry. ‘If you add small amounts of calcium and phosphate ions and the casein molecules to water, the calcium phosphate does not crystalise, and no micelles are formed. Slowly removing water from the solution increases the concentration, and micelles eventually form. Thus, tiny crystals are formed, which enable the production of better micelles in a controlled way. Moreover, this process is continuous and much faster.’
Without micelles
Antuma is frequently asked whether it is possible to make cheese from artificial casein proteins without first transforming them into micelles. ‘Humans have been making cheese from milk with micelles for some seven thousand years because micelles occur naturally in milk. Hence, cheese production methods are based on this approach’, Antuma states. He believes it may be possible to make cheese without micelles, but ‘that would require reinventing the (cheese) wheel.’
‘The power of precision fermentation lies in our ability to reproduce the key resource in the production of cheese with precisely the same proteins the cow makes. It would be great if we could process these proteins in precisely the same way we currently process animal proteins. But that requires proteins in the form of micelles.’ Nevertheless, he leaves the manufacturing of cheese to others. ‘My thesis provides new, fundamental knowledge of micelles and simultaneously provides insights into solutions to practical problems. It is now up to commercial businesses to produce cheese with animal-free casein micelles.’
