Influence of mastication and saliva on aroma release in a model mouth system

The influence of mastication, saliva composition and saliva volume on aroma release from rehydrated diced bell peppers and French beans was studied in a model mouth system. Released volatile compounds were analysed by gas chromatography combined with sniffing port and flame ionisation detection. Compounds were identified by gas chromatography/mass spectrometry, resulting in more than 40 compounds to be identified in each vegetable. Mastication increased release from bell peppers significantly and increased the number of volatile compounds with detectable odours in sniffing port analysis from six to 10 compounds. Addition of artificial or human saliva resulted in the same aroma profile for bell peppers. The amylase activity of artificial saliva consisting of human or porcine alpha-amylase was in the same range as amylase activity in human saliva at 37 degrees C. Bacterial alpha-amylase had lower activity. Human and porcine alpha-amylase in artificial saliva added to rehydrated French beans did not differ significantly in starch breakdown and affected aroma release similarly. Increase in saliva volume decreased release of aroma compounds from rc:hydrated French brans significantly. The artificial saliva with porcine or human alpha-amylase sufficiently simulated human saliva with regard to aroma release. The three parameters mastication, saliva composition and saliva volume were shown to be important factors in aroma release from rehydrated vegetables. (C) 2000 Elsevier Science Ltd. All rights reserved.