Quantification of lipid oxidation in dairy powders
Kieran Kilcawley, David Mannion, Holly Clarke
Industry impact: Lipid oxidation is a major contributor to the deterioration of food quality, resulting in the formation of undesirable compounds, odours and flavours in dairy powders, which can limit shelf life and product quality. The sensory perception and composition of milk powders is heavily dependent on the milk from which it was derived; and on processing parameters such as temperature, drying time, packaging material and storage conditions. Traditional methods to evaluate lipid oxidation in dairy powders can both under- and overestimate the problem. Identification and quantification of the key volatile compounds arising from lipid oxidation known to influence the sensory perception of dairy products is a significant step forward. A new method was developed and validated using headspace solid phase extraction gas chromatography mass spectrometry to quantify 13 critical lipid oxidation volatile aromatic compounds below their sensory perception thresholds. This method is already being used by producers of dairy powders to monitor quality and potentially predict shelf life.
Funding: Teagasc funding project 0044 (Profiling Milk from Grass).