Resumen de Cold-triggered/heat-destroyed emulsions composed of phospholipids and triacylglycerols as thermal history indicators for cold-chain distribution systems
Kohdai Nagata, Tatsuya Mizoguchi, Makoto Kitsunai, Kumi Hirose, Akira Hirasawa, Kazuhiro Chiba
BACKGROUND: Recently, cold-chain distribution systems have come to play important roles in worldwide food processing/storage/transportation networks. To ensure the maintenance of the quality and safety of foods, it is necessary to develop thermal history indicators for products involved in cold-chain distribution systems. To provide a record of the occurrence of a high-temperature event during a cold-chain system, a temperature-related phase change in a material within the indicator is needed to indicate that the high-temperature event occurred. Preferentially, for safety, the materials of the indicators should be edible and easy to handle. It should be possible to store the indicators at ambient temperature before use, and they should be triggered automatically just by cooling at the start of a cold-chain system. Furthermore, if the indicator is heated even once during the cold-chain distribution system, its appearance must be irreversibly altered to provide evidence of the high-temperature experience. RESULTS: Based on the edible materials composed of lyso-lecithin (15 g), lecithin (2 g), triacylglycerol (150 g), and water, we successfully constructed a stable emulsion that could be triggered just by cooling to 4 °C or lower for more than 12 h. After triggering, it was immediately destroyed by heating up to 20 °C or higher. Furthermore, the mechanism of cold-triggering and heat-destruction has been studied by nuclear magnetic resonance. CONCLUSION: The cold-triggered/heat-destroyed emulsion should be applied as a new thermal history indicator that can be automatically triggered just by cooling down and irreversibly change its appearance after a high-temperature experience in cold-chain distribution systems. Copyright © 2008 Society of Chemical Industry
