Forcing chilled shelf-life

With increasing pressure to develop and launch new products as quickly as possible, part of the product development cycle is to set a suitable shelf life. As 'real-time' testing is often too time consuming, there is demand for "accelerated shelf life testing" (ASL) that reliably predicts the actual life.

Currently no validated methods exist to perform ASL studies. For chilled food products there is a concern that the use of accelerated conditions to speed up the spoilage process, for example elevated storage temperature, could induce growth of different microorganisms to that which would occur under normal storage conditions.

However, initial results suggest that elevated temperature may be appropriate for accelerated shelf life testing of some chilled foods. We looked at the effect of elevated storage temperature on the growth of the natural microflora of cottage cheese. Samples were stored between 5 and 30°C, and tested over shelf life for pH, Aw, and various groups of microorganisms.

The main group of microflora in the cottage cheese product was lactic acid bacteria, and there was good agreement between the observed and predicted growth rate variation at the higher temperatures, suggesting that ASL would be suitable for products of this type. Work on other products is on-going.

Contact: Annette Sansom
+44(0)1386 842263
annette.sansom@campdenbri.co.uk