Quartz crystal microbalance gas sensor arrays for the quality control of chocolate

• A procedure to fingerprint chocolate headspace using porphyrin based and gold nanoparticles-peptide based gas sensor arrays has been developed.
• Gas sensor arrays have been tested on artificially prepared off-flavoured samples.
• Good discrimination was obtained using PLS-DA with higher performances for the gold nanoparticles-peptide based array.

Analysis of chocolate flavour through gas sensor arrays has been carried out. Two different set of sensors have been tested to assess the performance of the different sensor arrays: metallo porphyrins and gold nanoparticles peptide coated quartz crystal microbalances. Two series of chocolate samples containing differently formulated products (dark, white and milk) have been tested: the former made of samples obtained under standard process conditions, the second including samples added with some volatile compounds associated to degradation processes and/or low quality raw materials to obtain artificially off-flavoured samples.Analysis with both gas sensor arrays resulted in a good discrimination between standard and artificially off flavoured chocolate samples. The best performance was obtained using the gold nanoparticles peptide sensors with over 90% of correctly assigned samples.