Characterization of ginger starch-based edible films incorporated with coconut shell liquid smoke by ultrasound treatment and application for ground beef.

The aim of the present study was to investigate the structural and physicochemical properties of ultrasound-treated ginger starch-based edible films incorporated with coconut shell liquid smoke (CSLS), and determine the inhibitory effect of the films against Escherichia coli O157:H7 in ground beef during the storage at 4 °C. Ultrasound-treated CSLS-ginger starch films presented a better mechanical, barrier, thermal, and antibacterial properties. The antibacterial effect of CSLS against E. coli, S. aureus, E. coli O157:H7, Listeria monocytogenes, Salmonella Enteritidis, and B. cereus increased significantly with ultrasound treatment. The CSLS-films showed antibacterial activity against E. coli O157:H7 without negatively affecting the sensory attributes of ground beef. The films containing 15% CSLS reduced E. coli O157:H7 populations by 1.33 log cfu/g in ground beef during the 12-day-storage. The CSLS-starch films effectively inhibited lipid oxidation in the ground beef samples during the refrigerated storage. These results indicated that ultrasound-treated CSLS-ginger starch film has the application potential as a novel antimicrobial active packaging for proteinous foods.