A high-throughput cheese manufacturing model for effective cheese starter culture screening

Discipline: starter culture; Keywords: industrial cheese manufacturing, enzymatic coagulation, protein separation, proteolysis.

Miniature cheeses can open up new possibilities to screen cheese starter cultures and study many other aspects of cheese production in the factory. The study was reported by H. Bachmann and coworkers in the Journal of Dairy Science (2009), Volume 92, pages 5868-5882, using the title: A high-throughput cheese manufacturing model for effective cheese starter culture screening.

Industrial cheese manufacturing is a process characterized by a number of steps. First there is enzymatic coagulation of the milk, which is followed by protein separation, then carbohydrate removal and finally an extended period of bacterial fermentation. The number of variables in each step that can influence quality characteristics is vast, to the extent that it makes development of new cheese manufacturing protocols time consuming and expensive. To save on costs, several models have been proposed in the past to miniaturize the manufacturing process, but these efforts failed to accommodate the through-puts required for systematic screening programs.

Bachmann and coworkers apparently overcame some of the challenges. In their paper they described a protocol that allows the parallel manufacturing of about 600 cheeses in individual vats, each with individual process specifications. They developed protocols for the production of miniaturized Gouda- and Cheddar-type cheeses which can be manufactured from as little as 1.7 milliliter of milk, the end-product being a mere 170 milligram! The results show that the miniaturized cheeses closely resemble conventionally produced cheese in terms of acidification profiles, moisture and salt contents, proteolysis, flavour profiles and microstructure. Flavour profiling of cheeses manufactured with or without mixed-strain adjunct starter cultures enabled them to distinguish between the different cheeses, whereas addition of single-strain adjunct starter cultures designed to over-express important flavor-related enzymes, resulted in effects similar to those described in industrial cheese. Furthermore, by benchmarking against industrial cheese produced from the same raw materials, they found good correlation between the respective proteolytic degradation products and the flavour profiles.

The miniature cheese (or micro-cheese) model described in this paper, in addition to others described previously, provide new opportunities to simulate cheese manufacturing processes. This will also facilitate the comparatively rapid and inexpensive studying of the complex of interacting physical, biochemical and microbiological variables of cheese-making.