Starch-based food packaging films processed by reactive extrusion/thermo-molding using chromium octanoate-loaded zeolite A as a potential triple-action mesoporous material (reinforcing filler/food-grade antimicrobial organocatalytic nanoreactor)

Abstract

Starch-based films have two main problems, which must be addressed before being regarded as food packaging materials: high water sensitivity and poor mechanical properties. Keeping this in view, the present research work aimed to evaluate and analyze, in terms of the structural, thermal, physicochemical, surface, morphological, mechanical, rheological and antimicrobial properties, the effect of the addition of the Cr(Oct)3-loaded LTA as a potential triple-action mesoporous material (reinforcing filler/food-grade antimicrobial organocatalytic nanoreactor) of TPS-based films processed under REx conditions. The results of this study demonstrated that LTA can act well as a reinforcing filler for TPS-based films. Nonetheless, the innovative approach of using Cr(Oct)3-loaded LTA as a food-grade organocatalytic nanoreactor for TPS-based films did not diminish the water sensitivity as much as desired, nor did it increase the film's mechanical performance as much as expected (with respect to the TPS film system as a control). In contrast, the film containing the food-grade organocatalyst presented the best physicochemical and mechanical performance of the analyzed films, due to the organocatalytic crosslinking of the starch chains, thus obtaining SW, MC, WS, WA and SM values as low as 24 ± 3%, 17.3 ± 0.2%, 27 ± 1, 6 ± 1% and 0.5 ± 0.1%, respectively, while their mechanical properties: σm, εb, E and T were as high as 0.9 ± 0.1 MPa, 11 ± 1%, 0.121 ± 0.004 MPa and 6 ± 2 × 103 J/m3, respectively.