Conclusions
An intelligent and biobased indicator packaging material system was obtained mainly for food products that alter the pH value during the deteriorative process. Chitosan intelligent films presented a colour variation in function of pH range, in which it was observed a pink colour at acid pH, bluish-green at neutral pH and yellow at basic pH. The C-ATH films were insoluble in water and reduced in 27% the WVTR compared to CF. The ATH presence in chitosan matrix films could reduce the free sites that might interact with water molecules. The E and TS did not alter significantly in C-ATH as compared to CF, but the flexibility was reduced 47% (lower 3r) as a consequence of the lower moisture content. The C-ATH could offer an efficient alternative to trace down food packaging giving a safe and quality product package due to the pH variation information during the transport and storage.