Aroma analysis, truffle

We have previously carried out studies on fresh black truffle aroma by strip and trap / dynamic headspace analysis. Experiments were carried out with truffle flesh (1,2), entire truffles ( Talou,... 

Modification of Flavor Due to Thermal Processing. Despite the similarity of the chromatographic profiles of headspace volatiles of canned and fresh truffles, a sensory analysis carried out by a panel of experts reported a marked difference between the two aromas. 

Plant material Fresh Black Perigord Truffles (Tuber Melanosporum) for analysis were purchased by Pebeyre Ltd., a company specializing in truffle marketing. Collected essentially in the South East of France, they were fully ripe (4) and released their characteristic aroma. Received the day after gathering in wicker-baskets,-truffles were hsmd-picked and then stocked in a cold storage of 15 m. ... 

Sensory Validation of Sampling and GC Techniques The sensory evaluation was carried out by a panel of three judges (employees of Pebeyre Ltd.). For this study, an external odor port was attached to the gas vent (5) of the D.C.I. System and the rotary valve (4) was not switched (analysis using the Desorption - Concentration mode). Thus, after the thermal desorption of the volatiles from the trap, the rotary valve was positioned so that the unresolved aroma Isolate went to our sniffing port. The response was measured as similarity or dissimilarity to Black Truffle aroma. 

Sensory Evaluation of the contribution of identified compounds to the aroma In order to identify those compounds mainly contributing to the characteristic flavor of the Black Truffle, the odor of the individual components of the headspace analysis were tested by a panel of eight judges (trained in sensory evaluation of truffles). The compounds tested were diluted in vegetable oil, in a range of concentrations from 30 to 300 ppm. 5 point scales (5 = exceptionally good full truffle aroma, 1 = not different from solvent) were used for flavor imitation and intensity. 

F. Pelusio, T. Nilsson, L. Montanarella, R. TiUo, B. Larsen, S. Facchetti, and J. Madsen, Headspace solid-phase microextraction analysis of volatile organic sulfur compounds in black and white truffle aroma, J. Agiic. Food Chem. 43 2138 (1995). 

Table 1 lists volatiles identified in white and black truffle aromas by head-space SPME (lOO-pm PDMS) GC/MS, and Table 2 lists results by purge-and-trap (Tenax) GC/MS. Results obtained by HS-SPME-GC/MS agreed well with those obtained by headspace Tenax adsorption GC/MS for the volatile organic sulfur compounds, and the expected discrimination of the polar or very volatile compounds by HS-SPME was confirmed. Pelusio et al. concluded that HS-SPME-GC/MS is a powerful technique for analysis of volatile organic sulfur compounds in truffle aromas, but because HS-SPME (with PDMS fibers) strongly discriminates more polar and very volatile compounds, it is less suited for quantitative analysis. 

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