Aroma delivery from spray dried coffee containing pressurised internalised gas

A non-chemical, ingredient free method of enhancing aroma delivery during the preparation of instant coffee is presented. The approach detailed introduces a method for entrapping high pressure internalised gas within the pores of spray dried soluble coffee by cycling of both pressure and temperature. The headspace delivery of volatile aroma compounds during powder hydration was tracked by an atmospheric pressure chemical ionisation-quadrupole mass spectrometer, with a modified ion source. The release of pressurised gas on hydration caused a burst of volatile aroma compounds into the headspace, which was both faster (77%) and more intense (60%) than could be achieved using standard instant coffee or through the use of chemical effervescent agents alone (sodium hydrogen carbonate and citric acid). In addition, the process of natural gasification selectively accelerated the delivery of individual aroma compounds, with the time to maximum headspace intensity being reduced for both 2,3 butanedione and acetaldehyde. (C) 2012 Elsevier Ltd. All rights reserved.