Ideas fermenting for new and improved cheeses

Starter cultures are at the heart of dairy research in Europe. A network of scientists will identify new tools to give Europe's dairy industry the competitive edge over USA, New Zealand and Australia.

Starter cultures are at the heart of dairy research in Europe. A network of scientists will identify new tools to give Europe's dairy industry the competitive edge over USA, New Zealand and Australia.

The consortium of scientists, co-ordinated by Nizo food research in The Netherlands, worked on debittering and highlysing starter cultures, which could allow an effective quality control and improvement of cheese.

Starter cultures produce the enzymes that contribute to cheese flavour development through the breakdown and conversion of milk fats and proteins, the flavour precursors.

Bacteria have initially enough energy to take the precursors inside themselves, but breaking these molecules down requires so much energy that this ability soon disappears.

So, flavour development can only happen when the starters crack open, liberating the flavour enzymes into the media that surrounds them.

According to the project researchers, although food technologists know how to enable this break - called lysis - they were largely in the dark as to the actual mechanism behind it. More importantly, claim the researchers, they were unaware as to what would happen by increasing and accelerating this process.

Taking on board this mysterious area, the project scientists set out to better understand starter lysis and its role in cheesemaking, selecting popular European cheeses such as Cheddar, Danbo or Gouda for the laboratory and at pilot scale.

According to the researchers, experiments carried out during the first two years 'generated some promising results'. For example, highly autolytic starters were selected, and taste panels showed that the addition of these strains to a bitter starter resulted in an improvement on the cheese's sensory traits. The autolytic strains were produced at industrial scale to be tested at trials.

The scientists hope that results from their work could lead to both the development of new cheeses, and the acceleration of existing manufacturing procedures.

They also assert that their work could promote future developments in industries using fermentations for the manufacture of foodstuffs other than dairy products.

More information on the project can be obtained from the project co-ordinators Dr Jeroen Hugenholtz and Dr Wilco C. Meijer.