Tailoring microstructure of superabsorbent film for active food packaging using carboxy methyl cellulose and biogenic vaterite CaCO3-Ag hybrid microspheres

Eliminating microbial growth and preventing food degradation from excess moisture is an important technological advance in packaging. This article describes the development of a novel antimicrobial superabsorbent pad for food packaging, which uses carboxy methyl cellulose (CMC) as a polymer matrix and biogenic vaterite calcium carbonate microspheres loaded with AgNPs (CaCO3-Ag). The spherical vaterite CaCO3-Ag hybrid was obtained by precipitating CaCO3 from discarded eggshells in silver colloid. The vaterite CaCO3-Ag microspheres were incorporated into the CMC matrix, which underwent physical cross-linking initially and was further chemically cross-linked during film surface treatment. The resulting three-layer film exhibits improved hardness and modulus of 0.09 and 3.30 GPa, respectively. The crystallinity was enhanced, and water absorption capacity attained was 13.87 times of film weight. The antimicrobial activity with inhibition zones of 6 and 14 mm against Escherichia coli and minced pork bacteria, makes it suitable for use as an antimicrobial superabsorbent pad in meat packaging applications.