effect of pH on the formation of Maillard-derived aroma volatiles using a cooked meat system

The effect of pH on the formation of volatile compounds was investigated using minced beef in which the pH was adjusted within the range 4.0-5.6, by the addition of hydrochloric acid before cooking. The strong buffering capacity of the meat ensured that the pH did not vary during heating. Volatiles were analysed using headspace concentration and gas chromatography-mass spectrometry. The total quantity of volatile compounds increased as the pH decreased. A number of furanthiols and their oxidation products were preferentially formed at acid pH; some of these compounds had strong meaty aromas. The formation of other heterocyclic compounds such as thiazoles and pyrazines were favoured by higher pH.