Results and discussion
3.1. Optimisation of the active packaging
Creation of a novel active packaging based on antioxidants that
are able to prolong freshness and whiteness of mushrooms is a
huge challenge due to the difficulties in working with fungus. The
first challenge to cope with is an enzymatic deterioration of samples.
Without exception, in an enzymatic reaction direct contact
between the antioxidant and the enzymes taking part in the reaction
of discolouration is required to stop their activity. Most of the
publications in the scientific literature suggest total immersion (or
washing) of mushrooms in the active solution. However, active
packaging for fresh mushrooms does not assume direct contact
between the product and the active agent. Therefore, other
approach needs to be applied. As food safety must be necessarily
ensured, the used active agents need to be approved for being used
in contact with food by European legislation. Consequently, the
range of substances that can be tested is limited. Moreover,
mushrooms are very susceptible products. They are susceptible not
only to mechanical injuries but also to excess of active agents what
can make them quickly brown. So it is extremely difficult to find an
antioxidant working in this case. In addition, packaging needs to
provide appropriate exchange of gases. High respiration rate of
mushrooms results in high humidity level. When the humidity
level is too high, water condenses on the surface of packaging and
then drops down, causing quicker deterioration of mushrooms. But
if the humidity level is too low, mushrooms loose water and they
become dehydrated.