83B-13 |
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S. MIN and J. M. Krochta. Dept. of Food Science & Technology, Univ. of California, Davis, 1 Shields Ave., Davis, CA 95616-8598 Application of antimicrobial-containing edible films has advantages over the direct application of antibacterial agents onto food because edible films can be designed to slow antimicrobial diffusion from the surface of food. Lactoferrin and lactoperoxidase are components of whey protein that are separated and concentrated for their functional properties, including antimicrobial properties. Thus, edible films based on whey protein isolate (WPI) could be compatible matrices to hold these antimicrobial compounds at the surface of food. The first objective was to study effects of lactoferrin (LF), lactoferrin hydrolysate (LFH) and lactoperoxidase systems (LPOS), both directly and incorporated into WPI films, on the inhibition of Penicillium commune. The second objective was to compare the elastic modulus (EM), tensile strength (TS), and percentage elongation at break (%E), oxygen permeability (OP), and color of WPI films incorporating LPOS with those of WPI films without LPOS. The concentrations of LF, LFH and LPOS were in the range of 0.05-3, 0.05-3 and 0.01-1% (w/w), respectively. Inhibition effects were examined by measurement of inoculated media turbidity, inhibition zones on inoculated agar, and direct WPI film surface inoculation tests. EM, TS, and %E and OP were measured by following ASTM standard methods D882-01 and D3985, respectively. Hunter L, a, b, values were measured for film color determination. LF and LFH at 1% (w/w) or higher inhibited P. commune in 1% peptone water, but not in potato dextrose broth. Only WPI films incorporating 1% (w/w) LPOS inhibited growth of P. commune. The mechanical and physical properties of WPI films were not significantly changed by incorporation of LPOS (P>0.05). WPI films incorporating LPOS may be applied to foods to control the growth of P. commune with identical mechanical and physical properties to those of regular WPI films.
Session 83B, Food Packaging: Applications of edible coatings, antimicrobial films, and sensors in food packaging
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