Chitosan-glucose combo eyed as novel preservative
shelf-life of lamb in laboratory tests by two weeks, and may offer
industry with a novel and efficient preservative for meat products.
Writing in the journal Food Chemistry, lead author Sweetie Kanatt from the Bhabha Atomic Research Centre in Mumbai report that by heating chitosan with glucose produces a chitosan-glucose complex (CGC) via the Maillard reaction, and this complex has excellent antioxidant and antimicrobial activity. "CGC seems to be a novel natural preservative endowed with both antibacterial as well antioxidant activity and may find applications in the food industry," wrote the authors. Suspicion over chemical-derived synthetic preservatives has pushed food makers to source natural preservatives such as rosemary extract instead, and market analysts Global Information pitch the global food preservative market at €422.7bn ($575bn), reaching €522bn ($710bn) by 2008. The researchers tested the complex's antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and report that the IC50 value of CGC, a measure of the concentration at which 50 per cent of the free radicals are scavenged, was 51.1 micrograms per millilitre. When testing the antimicrobial activity of the complex against E. coli, Pseudomonas, Staphylococcus aureus and Bacillus cereus, the common food spoilage and pathogenic bacteria, Kanatt and co-workers report that the activity of CGC was similar to chitosan, with a minimum inhibition at concentrations of 0.05 per cent. The researchers then took the step of testing the complex in model meat products, formulating lamb meat and pork cocktail salami. Significant increases in shelf-life are reported, with extensions of 14 and 28 days reported for the products, respectively. "From the present studies that the chitosan-glucose complex (CGC) is a better preservative than chitosan alone. It showed superior antioxidant activity as compared to chitosan/glucose alone," wrote the researchers. "The antimicrobial activity of the CGC was identical to that of chitosan against the common food spoilers and pathogens such as E. coli, Pseudomonas spp, S. aureus and B. cereus." "CGC is endowed with both antioxidant and antimicrobial activity and thus is a promising novel preservative for various food formulations," they concluded. Source: Food Chemistry (Elsevier) doi:10.1016/j.foodchem.2007.06.036 "Chitosan glucose complex - A novel food preservative" Authors: S.R. Kanatt, R. Chander, A. Sharma