Packaging of Fresh Sliced Mushrooms with Essential Oils Vapours: A New Technology for Maintaining Quality and Extending Shelf Life

The use of vapour of essential oils (EOs) through an innovative pilot-plant packaging device was studied to preserve the quality of sliced mushrooms during storage. A mix of EOs (eugenol, bergamot EO, and grapefruit EO) was vaporized (100 and 125 mu L L-1) and applied during packaging of sliced mushrooms under modified atmosphere packaging (MAP); then, the product quality was studied during cold storage up to 12 days. The highest colour changes of EOs125 samples, which were observed in the mushroom stipe, were not observed with the EOs100 atmosphere. Thus, the high polyphenoloxidase activity observed in untreated samples after 5-7 days was highly controlled with the vapour EOs atmospheres. Furthermore, the visual appearance scores of EOs100 samples were still over the limit of usability, while untreated samples were already below this threshold after 5 days of storage. A strong bacteriostatic effect was achieved with vapour EOs, reducing the Pseudomonas spp. (the main microbial genus in cultivated mushrooms) growth by approximate to 1.7 log CFU g(-1), regardless of the EOs dose, after 12 days. The activity of phenyl ammonia lyase was also reduced up to approximate to 0.4 enzymatic units with the EOs100 treatment. Conclusively, packaging of sliced mushrooms under an atmosphere enriched with 100 mu L L-1 EOs vapour highly controlled the quality loss of sliced mushrooms owing to their enzymatic inhibition and high bacteriostatic effect.

Automated summary

In this study, the use of essential oil vapor was effective in preserving the quality of sliced mushrooms during storage by controlling enzymatic activity, color changes, and microbial growth. The vaporized essential oils showed high bacteriostatic effect and reduced phenyl ammonia lyase activity, contributing to the overall quality maintenance of sliced mushrooms.