Food safety issues caused by foodborne pathogens cannot be ignored,and packaging film is an efficient manner to prevent food contamination.The sandwich-like nanocomposite films were designed by the layer-by-layer asse...Food safety issues caused by foodborne pathogens cannot be ignored,and packaging film is an efficient manner to prevent food contamination.The sandwich-like nanocomposite films were designed by the layer-by-layer assembly technique,and the structure of these films was further densified by the chemical cross-linking of ferulic acid and the physical cross-linking of polyvinyl alcohol.The highest antibacterial efficiency of the nanocomposite film under light response,close to 100%,was achieved when N-Nb2CTx/TpPa-1/m-WO3-x of 0.2%was added.Simultaneously,the tensile strength of the nanocomposite film reached 10.67 MPa,the elongation at break was 140.83%,the water solubility decreased to 22.03%,the water vapor permeability decreased to 0.34 g mm/h⋅m^(2)⋅kPa,the oxygen transmission rate decreased to 5.19 cm^(3)/m^(2)×d×0.1 MPa,the water contact angle was 81°,and the scavenging rates of DPPH and ABTS were 46.55%and 65.08%.Finally,the shelf life of chilled beef wrapped with nanocomposite films was prolonged by 7 days compared with the control group and 5 days compared with PE film,which provided a novel concept for food packaging technology.展开更多
Endogenous protease degradation and pH dependence limit the practical application ofε-polylysine(ε-PL)as an antimicrobial agent in raw meat preservation.To expand the usage ofε-PL in raw meat,the study investigated...Endogenous protease degradation and pH dependence limit the practical application ofε-polylysine(ε-PL)as an antimicrobial agent in raw meat preservation.To expand the usage ofε-PL in raw meat,the study investigated the synergistic inhibitory effects ofε-PL and punicalagin(PU)against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)using micro checkboard method.The synergistic effects were quantified using fractional inhibitory concentration index(FICI)and fractional bactericidal concentrations index(FBCI).Bothε-PL and PU at the ratio of 1/4 MICε-PL+1/4 MIC PU showed FICI of 0.5≤0.5 and FBCI of 0.266≤0.5 for both S.aureus and E.coli,suggesting that the two have a synergistic effect.The actual inhibitory zone diameters ofε-PL/PU for S.aureus and E.coli were significantly higher than the theoretical summed values(p<0.05).The colony number of S.aureus and E.coli were reduced by 1000 times byε-PL/PU after 8 h and 12 h,compared to single treatments.Mechanistic studies revealed thatε-PL/PU synergistically disrupted cell membranes,increased leakage of alkaline phosphatase and proteins,and inhibited ATP production.ε-PL/PU demonstrated synergistic antioxidant effects in DPPH,ABTS,and lipid oxidation assays.Through application to the beef preservation,ε-PL/PU inhibited the rise in pH,microbial growth,maintained texture,and extended shelf life from 4 d to 8 d at 4◦C,and 1 d-3 d at 20◦C and 30◦C,respectively.Thus,ε-PL/PU is a potential synergistic strategy for food preservation.展开更多
基金supported by The National Key Research and Development Program of China(2022YFD2100500).
文摘Food safety issues caused by foodborne pathogens cannot be ignored,and packaging film is an efficient manner to prevent food contamination.The sandwich-like nanocomposite films were designed by the layer-by-layer assembly technique,and the structure of these films was further densified by the chemical cross-linking of ferulic acid and the physical cross-linking of polyvinyl alcohol.The highest antibacterial efficiency of the nanocomposite film under light response,close to 100%,was achieved when N-Nb2CTx/TpPa-1/m-WO3-x of 0.2%was added.Simultaneously,the tensile strength of the nanocomposite film reached 10.67 MPa,the elongation at break was 140.83%,the water solubility decreased to 22.03%,the water vapor permeability decreased to 0.34 g mm/h⋅m^(2)⋅kPa,the oxygen transmission rate decreased to 5.19 cm^(3)/m^(2)×d×0.1 MPa,the water contact angle was 81°,and the scavenging rates of DPPH and ABTS were 46.55%and 65.08%.Finally,the shelf life of chilled beef wrapped with nanocomposite films was prolonged by 7 days compared with the control group and 5 days compared with PE film,which provided a novel concept for food packaging technology.
基金supported by the National Natural Science Foundation of China(32402084).
文摘Endogenous protease degradation and pH dependence limit the practical application ofε-polylysine(ε-PL)as an antimicrobial agent in raw meat preservation.To expand the usage ofε-PL in raw meat,the study investigated the synergistic inhibitory effects ofε-PL and punicalagin(PU)against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)using micro checkboard method.The synergistic effects were quantified using fractional inhibitory concentration index(FICI)and fractional bactericidal concentrations index(FBCI).Bothε-PL and PU at the ratio of 1/4 MICε-PL+1/4 MIC PU showed FICI of 0.5≤0.5 and FBCI of 0.266≤0.5 for both S.aureus and E.coli,suggesting that the two have a synergistic effect.The actual inhibitory zone diameters ofε-PL/PU for S.aureus and E.coli were significantly higher than the theoretical summed values(p<0.05).The colony number of S.aureus and E.coli were reduced by 1000 times byε-PL/PU after 8 h and 12 h,compared to single treatments.Mechanistic studies revealed thatε-PL/PU synergistically disrupted cell membranes,increased leakage of alkaline phosphatase and proteins,and inhibited ATP production.ε-PL/PU demonstrated synergistic antioxidant effects in DPPH,ABTS,and lipid oxidation assays.Through application to the beef preservation,ε-PL/PU inhibited the rise in pH,microbial growth,maintained texture,and extended shelf life from 4 d to 8 d at 4◦C,and 1 d-3 d at 20◦C and 30◦C,respectively.Thus,ε-PL/PU is a potential synergistic strategy for food preservation.
