Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nan...Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nanocellulose suspension(1.5%,in mass)with the desired concentration of the pH-sensitive indicators,either red cabbage(RC)extract,black carrot(BC)extract,or chlorophenol red(CPR).The responsiveness of the colorimetric pH indicators,assessed visually and by CiE-Lab quantitative analysis,to the freshness of raw beef steaks stored under MAP conditions at 4℃ or 20℃,was analysed over7d.Results:All the indicators showed a colour change for beef steak stored at 4℃ for 7 d that was noticeable with the naked eye and had a △E value>12.The sensitivity of the RC pH indicator was superior to that of the BC and CPR pH indicators.A study linking total microbial count(aerobic+Escherichia coli+coliform)and the quantitative colorimetric response of the indicators(△E)revealed a strong linear correlation.Conclusions:The developed colorimetric pH indicators could be used to monitor the freshness of raw beef and as an alternative to the bestbefore date commonly used in pre-packagedmeat.展开更多
基金co-funded by Meat Livestock Australia(MLA)under the Monash Graduate Research Industry Partnership(GRIP)Program(project P.PSH.0889).
文摘Objectives:To deveop on-pack visual indicators for the real-time monitoring of raw beef steaks in a modified atmospheric packaging(MAP).Materials and Methods:Three indicators were prepared by spray deposition of a nanocellulose suspension(1.5%,in mass)with the desired concentration of the pH-sensitive indicators,either red cabbage(RC)extract,black carrot(BC)extract,or chlorophenol red(CPR).The responsiveness of the colorimetric pH indicators,assessed visually and by CiE-Lab quantitative analysis,to the freshness of raw beef steaks stored under MAP conditions at 4℃ or 20℃,was analysed over7d.Results:All the indicators showed a colour change for beef steak stored at 4℃ for 7 d that was noticeable with the naked eye and had a △E value>12.The sensitivity of the RC pH indicator was superior to that of the BC and CPR pH indicators.A study linking total microbial count(aerobic+Escherichia coli+coliform)and the quantitative colorimetric response of the indicators(△E)revealed a strong linear correlation.Conclusions:The developed colorimetric pH indicators could be used to monitor the freshness of raw beef and as an alternative to the bestbefore date commonly used in pre-packagedmeat.
