Pierre Giampaoli

Furan quantification in bread crust: development of a simple and sensitive method using headspace-trap GC-MS

ABSTRACT To study reactivity in bread crust during the baking process in the pan, we followed furan mainly resulting from Maillard and caramelisation reactions in cereal products. Furan quantification is commonly performed with automatic HS-static GC-MS. However, we showed that the automatic HS-trap GC-MS method can improve the sensitivity of the furan quantification. Indeed, this method allowed the LOD to be decreased from 0.3 ng g–1 with HS-static mode to 0.03 ng g–1 with HS-trap mode under these conditions. After validation of this method for furan quantification in bread crust, a difference between the crust extracted from the bottom and from the sides of the bread was evident. The quantity of furan in the bottom crust was five times lower than in the side crust, revealing less reactivity on the bottom than on the sides of the bread during the baking process in the pan. Differences in water content may explain these variations in reactivity.

Searching the missed flavour: chemical and sensory characterisation of flavour compounds released during baking

Abstract An original ‘on-line’ system coupled with SPME (solid phase microextraction) and GC-MS analysis was developed in order to extract and analyse aroma compounds released during baking. Four different SPME fibres were used in order to investigate their extraction efficiency and how well they represented the odour produced during baking. A similarity test showed that the global odour emerging from SPME extracts was close to that of the reference (the odour of the baking cake). The hedonic test on SPME extracts and gas-chromatography coupled to olfactometry allowed to identify key odorant zones related with the ‘tasty’ odour of cake baking.

Evolution of Volatile Compounds during the Distillation of Cognac Spirit

Cognac wine spirit has a complex composition in volatile compounds which contributes to its organoleptic profile. This work focused on the batch distillation process and, in particular, on volatile compounds specifically produced by chemical reactions during the distillation of Cognac wine spirit, traditionally conducted in two steps with charentais pot stills. The aim of this study was to characterize these volatile compounds formed during distillation. Sampling has been performed on the distillates and inside the boiler during a typical Cognac distillation. The analysis of these samples allowed us to perform a mass balance and to point out several types of volatile compounds whose quantities strongly increased during the distillation process. These compounds were distinguished by their chemical family. It has been found that the first distillation step was decisive for the formation of volatile compounds. Moreover, 2 esters, 3 aldehydes, 12 norisoprenoids, and 3 terpenes were shown to be generated during the process. These results suggest that some volatile compounds found in Cognac spirit are formed during distillation due to chemical reactions induced by high temperature. These findings give important indications to professional distillers in order to enhance the products quality.