Papers by Author: Dong Hong Liu

Abstract: Time-Temperature Indicator (TTI) is an intelligent or smart package. It is a simple device that can be attached to food packaging to indirectly reflect the full or partial temperature history and quality status of the food product. TTI is utilized widely throughout food processing and distribution of cold chain. An alkaline lipase TTI has been developed, which based on the reaction between alkaline lipase and glycerol tributyrate. Experiments under several isothermal conditions (1.3°C，6.1°C，10.9°C，15.5°C，20.6°C，25.4°C) were conducted and the Arrhenius parameters of the TTI were derived. The developed TTI chemical reaction system showed an Arrhenius behavior, the activation energy was 45.07±2.25 kJ/mol.

Abstract: Cylindrical liquid can of water and CMC was simulated by solving the governing equations for continuity, momentum and energy conservation, using “COMSOL®” multiphysical coupling field software package which based on finite element method of analysis. Through finding out cold spot of 100 °C, 105 °C，110°C and 115°C in the can and sterilization minimum value spot, temperature and sterilization value were compared. The results indicated that there were differences between cold spot and F minimum value spot. thus, in order to ensuring food safety, the original sterilization time should be moderately prolong, especially for thinlyfluid.

Abstract: A non-contact ultrasonic system to monitor the yogurt fermentation process through a stainless steel reactor wall is described. During the process, the acoustic impedance was determined by using multiple reflections of ultrasound within the stainless steel wall. Thus, the wall was part of the measurement system. By basing on measurement multiple reflections, the instrument sensitivity is increased by the power of the reflection coefficient. Experimental results show that the acoustic impedance changes continuously while pH declines. It is very useful, especially on production scale for yogurt that the acoustic impedance measurement does not demand a liquid transparent to ultrasound. Also, this noncontact sensing method can reduce the risk of food contamination from measuring instrument, and contribute to hygienization for food manufacture industries.