EFFECT OF HYDRATION ON RELEASE OF VOLATILES FROM CEREAL FOODS

The aroma of food is commonly analysed by collecting the volatiles in the air above the food (the headspace) and identifying and quantifying the collected compounds by gas chromatography-mass spectrometry. Anal ysing the headspace of food prior to eating does not take into account changes to the food that occur in the mouth (such as increase in surf ace area, hydration or phase change), and aroma release under mouth co nditions is no longer a simple partition between the food and the air but a more complex phenomenon. For the first time, we have measured (i nstrumentally) the release of individual aroma compounds from dry cere al foods as they hydrate and have related this to the conditions found in the mouth. It is clear that different aroma profiles exist at diff erent times during eating This is important as people are capable of p erceiving changes in aroma as they eat a food and we are all familiar with sensations such as the initial burst of aroma on biting food and aftertastes. By measuring aroma release instrumentally and comparing t he pattern of release with sensory perception of the same food we may begin to understand the subtle factors that affect aroma release and o ur enjoyment of food. (C) 1996 Academic Press Limited