Scientist - News - 02-10-2009:
Encapsulation protects probiotics against heat
Beintema, Nienke
Danisco recently presented a new technology to make probiotics
heat-resistant. The discovery fits into a trend in the food and health
industry: encapsulation. This technology opens up possibilities of widely
expanding the range of probiotic products.
The vast majority of probiotic products are dairy products, such as
yoghurts, which are sold fresh and refrigerated. The reason for this
is primarily traditional: this used to be the only way to deliver probiotic
bacteria to our digestive tract alive. Today, however, encapsulation
technologies are available that allow for a much wider range of probiotic
products: dry products, and products with a long shelf life, for instance.
Probiotic muesli bars, chocolate, chewing gum and sports drinks are
now entering the market.
Shelf life
Danisco is currently opening up a new range of applications: probiotics
in food products that have to be heated during production, such as cheeses.
Temperatures above 40 degrees Celsius are usually fatal for probiotics,
but the Danisco technology – soon to be patented – brings
temperatures above 50 degrees within reach, and in the long term even
higher. So far its trials have found that the technology achieves a
tenfold increase in Lactobacillus acidophilus heat resistance.
In addition, the encapsulated probiotic retained 60% viability after
five months’ storage at room temperature in a moist muesli bar.
In dry products, shelf life even exceeds 24 months. Moreover, when tested
in a cheese application, these probiotics proved 2,500 times more resistant
to processing conditions than non-encapsulated controls.
Polymers
Encapsulation is generally applied for three reasons: it protects the
bacteria from influences of the food in which they are administered;
it extends the products’ shelf life; and it protects the bacteria throughout
the first part of the digestive tract, notably against stomach juices.
The technologies range widely; several hundreds are available today,
and a similar number of companies and research institutions are working
on them. Conferences are held each year focusing just on this topic,
and there is even a scientific journal called Encapsulation.
In most cases, the capsules consist of a biodegradable polymer material,
such as polysaccharide gels. Some companies even work on capsules made
out of milk protein. Capsules are typically below a tenth of a millimeter
in diameter. Danisco has not yet released the details of its technology,
pending the patent application, but aims to achieve not only better
bacterial survival, but also cheaper and easier manufacture.
More information:
Danisco press release
Overview of technology in the journal Encapsulation
Abstract on encapsulation presented at the 14th European Congress on Biotechnology (Barcelona, 13/16-09-09)