Taste–aroma interactions in a citrus flavoured model beverage system: Similarities and differences between acid and sugar type

A model citrus flavoured beverage was created to investigate the effect of varying levels of sugars and acids on flavour and taste perception. Two naturally occurring sugars; glucose and fructose, and two organic acids; citric and lactic acid, were studied using D-optimal design spaces created using experimental design software (Design Exp). Perception was studied using the scaling technique of magnitude estimation by a panel of trained assessors. Alterations in aroma volatile release profiles and viscosity were measured instrumentally using APCI-MS and rheometry, respectively. Aroma release profiles were unaffected by varying tastant levels and only the highest level of glucose (150 g/l) resulted in a small increase in viscosity. However, flavour perception was increased on addition of tastants, although, interestingly, glucose showed a different profile to fructose despite equi-sweet levels being used. This data provides evidence for taste–aroma interactions within this citrus flavoured system which are not due to physico-chemical interactions within the beverage matrix. This study has also uncovered apparent differences between effects of fructose and glucose on flavour perception, again not due to alterations in physical factors, and raises the intriguing possibility of different receptors/receptor mechanisms between the two monosaccharides.