Development of antiviral and bacteriostatic chitosan‐based food packaging material with grape seed extract for murine norovirus, <i>Escherichia coli</i> and <i>Listeria innocua</i> control

Abstract

Edible coatings and films based on chitosan, and containing grape seed extract (GSE), were developed and their activities tested against murine norovirus (MNV-1), <i>Listeria innocua</i> and <i>Escherichia coli</i> K12. Grape seed extract concentrations of 1%, 1.5%, and 2.5% dissolved in deionized water resulted in MNV-1 plaque reductions (<i>p</i> < .05) of 1.75, 2.60, and 3.58 log PFU/ml, respectively after 3 hr. Two percent (w/w) chitosan solutions incorporated with 2.5% and 5% GSE also significantly (<i>p</i> < .05) reduced MNV-1 titers by 2.68 and 4.00 log PFU/ml, respectively after 3 hr. Additionally, incorporation of the GSE into the chitosan films also showed antimicrobial efficacy against MNV-1, <i>L</i>. <i>innocua,</i> and <i>E</i>. <i>coli</i> K12. Chitosan films containing 5%, 10%, and 15% GSE caused MNV-1 reductions of 0.92, 1.89, and 2.27 log PFU/ml, respectively, after 4 hr of incubation. Also, after 24 hr, the 5% and 10% GSE films reduced MNV-1 titers by 1.90 and 3.26 log PFU/ml, respectively, while the 15% GSE film reduced MNV-1 to undetectable levels. For <i>E</i>. <i>coli</i> K12, there were reductions of 2.28, 5.18, and 7.14 log CFU/ml after 24 hr exposure by the 5%, 10%, and 15% GSE films, respectively. Also, <i>L</i>. <i>innocua</i> counts were reduced by 3.06, 6.15, and 6.91 log CFU/ml by the 5%, 10%, and 15% GSE films, respectively. This study demonstrated that GSE in edible films and coatings is effective against the organisms tested, and this shows that they are effective against foodborne microbes of public health concerns.