Changes in flavour and aroma compounds of ultra‐high‐temperature processed and aseptic‐filled milk caused by storage conditions (temperature and duration)

The changes during a 4‐month storage period at 5 or 25°C were investigated for sensory characteristics, volatiles and odorants of indirect (plate‐type) ultra‐high‐temperature processed and aseptically filled milk. Quantitative descriptive analysis (QDA) showed that “plastic odour” and “smoothness” were stronger in the milk stored at 25°C for 2 and 4 months versus 5°C. Principal component analysis (PCA) of gas chromatography–mass spectrometry data revealed that the volatile profile change was larger at 25°C versus 5°C and that the storage duration at 25°C affected the volatile profile. Gas chromatography‐olfactometry (GC‐O) confirmed that similar changes were dependent on the storage temperature. A “coconut” odour contributed to the change in the odour profile. The QDA and GC‐O results suggest that the increase in the “plastic odour” was a specific change associated with the 25°C stored milk and that ( Z )‐6‐dodecen‐4‐olide, which had the strongest “coconut” odour, was related to the “plastic odour”.