THE EFFECT OF EATING ON AROMA RELEASE FROM STRAWBERRIES

The aroma of strawberries was sampled directly from the expired air of people eating strawberries and by a headspace method which had been d esigned to mimic maceration in the mouth. Comparison of the aroma prof iles showed that, using the modified headspace technique, it was possi ble to produce headspace profiles for the esters, very similar to the profile observed in the nosespace. The C6 aldehydes hexanal and (E)-2- hexenal were present at higher amounts in the headspace than the noses pace. The amounts of these volatiles in the headspace of strawberries increased as the homogenisation period increased. Reducing the duratio n of homogenisation before headspace collection resulted in lower amou nts of C6 aldehydes and headspace profiles virtually identical to the nosespace profiles. The rate of release of aroma volatiles from strawb erries during eating was also investigated. This demonstrated that the maximum concentration of aroma volatiles occurred at the point of swa llowing. Prior to this, volatile concentrations were 40-60% of the max imum level observed: this is likely to have been associated with swall owing the juice and saliva present in the mouth at this time, resultin g in transfer of volatiles to the nasal cavity. The volatiles which pe rsisted the longest in the nosespace were the smaller esters, methyl a cetate and ethyl acetate. This may be due to the differences in polari ty between these compounds and other less-polar esters such as methyl butanoate.