Functional properties of clay nanofillers used in the biopolymer-based composite films for active food packaging applications - Review

Biocomposite films (derived from polysaccharides, proteins, gums and microbial origin) have poor physical and mechanical properties. The nonbiodegradable synthetic polymers have good film characteristics, but it has unavoidable environmental concerns. In order to meet the food packaging demand and the environmental concerns associated with commercial packaging, biopolymer matrix with nanoclay reinforcements could be used as an alternative solution. Nanoclays, as filler materials in biopolymer matrix, helps to improve functional characteristics, such as: mechanical strength, optical, thermal, rheological, gas and water vapor barrier properties of biocomposite films. Nanoclays are administered as filler materials because of their high aspect ratio in the individual layers and specific chemical properties. However, uniform and complete dispersion of filler materials in the biopolymer matrix is necessary for a well-ordered morphology and structure of films. Nanoclays are capable of creating better reinforcement with greater impact on the tensile strength and gas barrier properties of food packaging films. This review aims to focus on the importance of nanoclay fillers in influencing the characteristic parameters of biocomposite materials. Although nanoclays are conveniently used, the toxicity profiles of nanoclays are least known. We have also discussed the toxicity and migration of nanoclays in food stimulants thereby, resolving the utility and safety of nanoclays on food packaging materials.