Antibacterial activity of pectic-based edible films incorporated with Mexican lime essential oil

Edible films have been used as carriers of foods additives such as antioxidant or antimicrobial agents. Lime essential oil has demonstrated to act as an antimicrobial agent on food systems which can be incorporated into a film matrix. In this research edible films were prepared with two different raw matters, lime bagasse pectic extract and lime pomace pectic extract at 0.70, 0.85 and 1.00% pectin equivalents. Mexican lime essential oil was incorporated to a film-forming solution at 0, 500 and 1000 mg L−1 and 0.70% glycerol was added as plasticizer. Edible films antibacterial activity against food-borne pathogenic bacteria (Escherichia coli O157:H7, Salmonella Typhimurium, Bacillus cereus, Staphylococcus aureus and Listeria monocytogenes) was investigated by the disc diffusion method, with zones of inhibition measured after 24 h of incubation. The higher inhibition zone was against E. coli (20.6 ± 1.17 mm). Edible films prepared with pectic extracts (Mexican Lime bagasse and pomace) presented higher inhibition against Gram negative bacteria, but those prepared with bagasse pectic extract were more effective against all five bacteria studied. Pectic extracts edible films incorporated with Mexican lime essential oil inhibited the growth of foodborne pathogenic bacteria and can be useful in the preservation of food to increase shelf life.