Polylactic acid/zinc oxide biocomposite films for food packaging application

Effect of PLA/ZnO Packaging and Gamma Radiation on the Content of Listeria innocua, Escherichia coli and Salmonella enterica on Ham during Storage at 4 °C

“…The main result from the DSC is that both the films, as obtained from the calender, are amorphous, that is the PLA does not crystallize, neither when there are the ZnO particles. This is in agreement with the spectra obtained by the X-ray which show clearly no presence of any crystallization peak [33]. Fig.…”

“…coli are in disagreement with the result in Marra et al [33], where for E. coli, it was reported that already after 1 day, the percent reduction was 99.99 (that is a value of CFU/mL close to 0), whereas, in this work a bacterial count of 2.82 log CFU/g at day 5 is obtained with the ham covered with the PLA/5% ZnO. The different results are very likely derived by to the diverse methodologies used; the methodology used in Marra et al [33] and those in the above reported literature consisted generally in the immersion of the plain ZnO or films with ZnO immersed in the bacterial solutions; this methodology can be defined as "experiment in solution"; whereas in this work the films were lying on the ham slice, which could be defined as "dry experiment".…”

“…The different results are very likely derived by to the diverse methodologies used; the methodology used in Marra et al [33] and those in the above reported literature consisted generally in the immersion of the plain ZnO or films with ZnO immersed in the bacterial solutions; this methodology can be defined as "experiment in solution"; whereas in this work the films were lying on the ham slice, which could be defined as "dry experiment". The two proposed mechanisms of efficiency of ZnO against bacteria require the presence of water (where H 2 O 2 can be formed or where the bacteria can have enough mobility to in contact with ZnO particles and so to be damaged).…”

“…In a previous paper [33], the effect of ZnO on the mechanical (tensile), permeability and antimicrobial properties of PLA based films was investigated. The study was performed on three films, with 1, 3 and 5 wt% of ZnO, and the antimicrobial test was done only with E.coli.…”

Assessment on the Effects of ZnO and Coated ZnO Particles on iPP and PLA Properties for Application in Food Packaging

“…[1][2][3][4][5][6][7]. Application of these technologies in food packaging is, therefore, considered highly promising since these technologies could also improve safety and quality of food and the research is oriented not only to materials with increased mechanical properties and reduced permeability but also those having antimicrobial properties [8][9][10][11][12][13][14][15][16][17]. It has been shown that the use of active agents, incorporated in the polymeric material for packaging, increases the shelf-life of the packaged product (life duration of a foodstuff before its consumption), acting on those mechanisms of degradation that cause food deterioration and reducing/inhibiting the growth of pathogens [18][19][20].…”