Instrumental taste and texture measurement

We investigate the taste and aroma compounds of fermented foods that contribute to their flavour. We do this by measuring free amino acids, volatile compounds (by GC-MS), small metabolites (by NMR) and peptides that are products upon fermentation.

Amino acids and small peptides activate human taste receptors, and contribute to the distinct sensory properties that fermentation imparts on food organoleptic properties. They are important determinants of the sensory experience.

Small proteins and peptides are able to activate specific human taste receptors that correspond to bitter taste, savoury (umami) and creaminess (kokumi) mouthfeel. 

Peptide fingerprinting uses minimal sample preparation in combination with matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry to allow for a rapid means to differentiate fermented products based on a distinctive pattern of peptides and thus the chemical composition of different fermented products.  

We use a peptidomic approach to identify and characterise peptide sequences, and allow for further comparison of relative quantities of peptides of interest, contrasting peptide modifications between products and predict peptide functionality. 

Peptides typically exert their functional properties by binding to target proteins, such as receptors. Interactions of peptides with receptors can be modelled in silico to predict which peptides might bind. Using molecular docking software, virtual screening of large numbers of peptides can be done in a high throughput fashion. Examples of applications include identification of peptides that could enhance creamy mouthfeel (kokumi) through activating the calcium sensing receptor (CaSR).

Below, the images shows how molecular docking software allows us to pinpoint the position and visualise the binding of a peptide of interest within the binding pocket of the receptor.