activity of NAT coatings could be exerted by direct contact rather
than through a progressive release of the active substance to a food
product. This can represent a great advantage since a very little
amount migrates to food. Moreover, the liquid environment
employed to test the release kinetics most probably leads to overestimate
the result when compared to the real amount that may
migrate to a solid product as a cheese sample.
Our results can also be considered an indirect way to assess the
stability of the coatings when placed in water, since even at the
highest content of PVOH (CoD samples), contact with water does
not affect the integrity of the network.
In the insert of Fig. 4, the linear plot obtained by calculating the
percentage of released NAT with respect to the entrapped one is
reported. It can be seen that this value shows a positive correlation
with the percentage of PVOH. In addition, this behaviour is related
to the above-mentioned swelling process: the loosening of the network
with extremely mobile chains, deriving from water contact,
facilitated the loss of NAT.