Effects of Nanoparticle Concentration and Plasticizer Type on Colorimetric Behavior of Polydiacetylene/Silica Nanocomposite as Time-temperature Indicator

Novel Color Change Film as a Time-Temperature Indicator Using Polydiacetylene/Silver Nanoparticles Embedded in Carboxymethyl Cellulose

Time-temperature indicators (TTIs) can be important tools in product applications to monitor food quality losses, especially for fruits and vegetables. In this context, the effects of silver nanoparticles (AgNPs) and glycerol on the color change of polydiacetylene/AgNPs (PDA/AgNPs) embedded in carboxymethyl cellulose (CMC) film as time-temperature indicators (TTIs) were investigated. A CMC film prepared with 30 mg/L AgNPs and a 1:3 (v/v) PDA:AgNP ratio exhibited a faster color change than under other conditions. At 35 °C, the films with PDA/AgNPs changed color from purplish-blue to purple and purple to reddish-purple over time due to the higher thermal conductivity of AgNPs and larger PDA surface area exposed to specific temperatures. The total color difference (TCD) of PDA/AgNP-embedded CMC film directly changed with regard to time and temperature. However, adding glycerol to the system resulted in a symmetrical chemical structure, a factor that delayed the color change. Scanning electron micrographs showed AgNPs embedded in the CMC films. Transmission electron micrographs indicated a core-shell structure of PDA/AgNP vesicles in the CMC matrix. PDA/AgNP vesicles were confirmed by second derivative Fourier transform infrared spectroscopy, with a new peak at 1390-1150 cm-1. The kinetics of TTIs from PDA/AgNP-embedded CMC films yielded an activation energy of 58.70 kJ/mol.

Emerging Meat Processing Technologies for Microbiological Safety of Meat and Meat Products

A consumer trend toward convenient, minimally processed meat products has exerted tremendous pressure on meat processors to ensure the safety of meat and meat products without compromising product quality and the meeting of consumer demands. This has led to challenges in developing and implementing novel processing technologies as the use of newer technologies may affect consumer choices and opinions of meat and meat products. Novel technologies adopted by the meat industry for controlling foodborne pathogens of significant public health implications, gaps in the technologies, and the need for scaling up technologies that have been proven to be successful in research settings or at the pilot scale will be discussed. Novel processing technologies in the meat industry warrant microbiological validation prior to becoming commercially viable options and enacting infrastructural changes. This review presents the advantages and shortcomings of such technologies and provides an overview of technologies that can be successfully implemented and streamlined in existing processing environments.