Have you ever spotted pink discoloration on cheese? It happens, and it results in millions of euro lost by the Irish cheese industry, says Bhagya Rekha Jonnala.

Science Week

Second-year PhD student Bhagya Rekha Jonnala is trying to find the source of pink discoloration on cheese and, in doing so, learn to prevent it.

Working at the Teagasc Food and Agriculture Research Centre, she has already used DNA extraction techniques to identify the bacteria she believes is responsible for the discoloration, which results in millions of euro lost by the Irish cheese industry (because no one wants to eat pink-spotted cheese).

As Jonnala explained during her Researchfest presentation at Inspirefest 2017, this particular Thermus bacterium is not harmful but it is known to produce carotenoids, the vivid pigments that make tomatoes red and carrots orange.

Isolating the bacterium that makes cheese blush is just the start. Jonnala also needs to find out what other factors – such as light, temperature or other conditions – are influencing the pink discoloration. And so, her cheesy research continues.

Words by Elaine Burke