Potential of a smart gelatine hydrogel-based package to extend fresh black truffle (Tuber melanosporum) shelf-life preserving its aroma profile

Abstract

Many post-harvest technologies have been applied to prolong the shelf life of black truffles; however, most of them negatively modify the genuine fresh truffle aroma. A novel edible gelatine hydrogel-based package (GHP) was tested to extend the shelf life of truffles and trap the aromatic compounds released by fresh truffles. First, the key physicochemical properties and microbiological and sensory attributes of the materials were characterised. The aromatic profile (by gas chromatography and a trained panel) and microbiological populations were monitored for 35 days in truffles stored in GHP and gelatine. Truffle preservation in GHP was compared to that in microperforated modified atmosphere packages (MAP) and that in macroperforated packages (C). The gelatine hydrogel exhibited extraordinarily high oxygen permeability and maintained a low microorganism load during storage (<4 log CFU·g?1 after 28 days). Some key volatile organic compounds were detected in the gelatine after seven days. Gelatine from GHP reduced microbial growth in truffles compared to the C and MAP conditions at day 21. Firmness loss at day 28 was an indicator of spoilage behaviour; therefore, 21 days was selected as the shelf-life extension of truffles under GHP, obtaining fresh truffles with high quality and an edible gelatine hydrogel with truffle aroma.