Screening of volatile compounds composition of white truffle during storage by GCxGC-(FID/MS) and gas sensor array analyses

Abstract

White truffle (Tuber magnatum Pico) is one of the most valuable delicacies of the Italian and French cuisine. Previous works on truffle aroma report sulfur compounds and short-chain aldehydes as typical constituents which abundance is influenced by storage conditions. In this study, the head space of truffle aroma has been evaluated by two different (innovative) approaches: HS-SPME extraction and comprehensive two-dimensional gas chromatography (GCxGC), exploiting a dual-stage loop-type modulator within a GC system with simultaneous FID and MS double detection, analysis and Gas sensors array system analysis. Gas chromatographic peak identification was carried out by means of dedicated laboratory-made GC–MS libraries and comparison of Retention Indices with those retrieved from literature, while peak quantification by means of a specifically designed software for comprehensive GC. The truffle samples were stored at +8 °C for four days in three different ways: wrapped in blotting paper or covered by rice or under vacuum. Eighty compounds were identified with high confidence (>90% of mass spectra similarity). PCA of compounds relative percentages showed differences among the fresh product and truffles stored in rice and under vacuum; on the contrary no significant volatiles composition modification was observed for truffles stored in paper.