Conclusions
A novel active packaging approach that extends the shelf-life of
packed fresh mushrooms has been studied herein. The active
packaging exhibited antioxidant properties without being in direct
contact to mushrooms. It is worth pointing out that developing a
new active packaging for extending the freshness of white sliced
mushrooms is not an easy task to achieve. Various obstacles and
limitations can be mentioned, such as difficulties in finding an
appropriate antioxidant that works comprehensively, is safe and
can be incorporated into the packaging material without any
problems. Nevertheless, the work here presented shows that it is
feasible. The use of sulphur dioxide incorporated into the packaging
improved the quality of mushrooms during their shelf-life. This
improvement was supported by visual evaluation (photos), by
measuring the mushroom whiteness and by the evaluation of
consumers' acceptance from a trained panel. The ratio of citric acid
to sodium metabisulphite was critical to maintain the white colour
of fresh sliced mushrooms without yellowing the edge of the surface,
which led to consumers' rejection. It was proved that sulphur
dioxide was not present in the samples after the storage time, as its
concentration was below 3.2 mg sulphur dioxide/g of mushrooms,
which fulfils the European legislation.