Effect of lyophilisation in the black truffle (Tuber melanosporum) aroma: a comparison with other long-term preservation treatments (freezing and sterilization)

The aim of this work was to evaluate the effect of different preservation methods (freeze-drying or lyophilisation, traditional freezing and canning) on the aroma profile of Tuber melanosporum truffles.
Volatile compounds were extracted by a solid-phase microextraction (SPME) technique and further analysed by gas-chromatography olfactometry, in order to monitor changes occurring in key-aroma compounds as a result of the technology applied.
Samples were also submitted to descriptive sensory analysis by a panel of trained judges, and to a preference (ranking) test by a group of truffle experts.
Data revealed that the aromatic profile of T. melanosporum freeze-drying truffle was less modified with respect to the genuine truffle aroma than the rest of products.
Freeze-drying was the only treatment able to keep truffle key-compounds such as dimethylsulphide (DMS) and dimethyldisulphide (DMDS), evoking a typical black olives aroma.
On the contrary, several aldehyde compounds (methional, hexanal and Z-4-heptenal) appeared as important odour molecules, which could influence the final aroma of the product.
Descriptive analysis and expert’s ranking showed the relative proximity among fresh and freezed-drying truffle, and confirmed the deep changes occurring in aroma as a consequence of the traditional freezing and canning process.
Freeze-drying arises therefore as an adequate technique to better preserve the original aroma of fresh truffle.

VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits – Ethical and Technological Issues

P. Marco, E. Campo, R. Oria, D. Blanco, M.E. Venturini

truffle aroma, preservation methods, freezed-drying, olfactometry, sensory profile

https://doi.org/10.17660/ActaHortic.2018.1194.117