Cheese, please
3 Feb 2003
As generations of students have discovered, milk can turn into cheese with apparently blinding speed. But in the cheesemaking industry, where the leave-the-carton-on-the-window-sill technique isn't practical, speed of cheesemaking is a critical issue.
According to researchers in New Zealand, genetic modification could provide an answer, although it's likely to be a controversial one.
The researchers, led by Goetz Laible of Agrisearch, based near Hamilton, implanted genes to overproduce two varieties of a milk protein, casein, into cow embryoes, the team reports in a current issue of Nature Biotechnology.
The enhanced milk has properties which give it advantages in cheesemaking. One of the proteins, kappa-casein, increases the heat stability of the milk, while the other, beta-casein, reduces the clotting time of the milk proteins and increases the expulsion of whey. The cows produce milk with 8-20 per cent more beta-casein, and twice as much kappa-casein as normal milk.
Using enhanced milk could help cheese producers save considerable amounts of money by reducing production times, the researchers say. However, opposition from anti-GM campaigners is likely to be fierce.
