A thesis submitted in partial fulfillment o f the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development

Thesis (M. Sc.) - Asian Institute of Technology, 2016

Nile tilapia is one of the important specie for consuming and exporting in Thailand. The study of Nile tilapia supply cha in in Thailand was determined with the handling techniques that can affect quality of Nile tilapia. There were two handling methods; oxygen supply and ice covering. The effects of both techniques to quality of Nile tilapia fillets were examined within insp ected time for 1, 2 and 4 hours . They were no correlation between handling techniques on physical, chemical, microbial growth, but the trends in texture profile analysis, lightness and sensory score affected. In addition, fluctuation temperature cycle on storage had effects on quality of tilapia meat. Drip loss was fluctuated, and imped ance decreased exactly at 100 kHz . Tilapia meat seemed to be softer with time as seen in texture profile analysis, firmness and cutting strength. Chemical parameters as TVB - N and pH rose in abu- sive group significantly, and quality index method and 9 point Hedonic scale can be used to determine freshness of tilapia when temperature fluctuation occurred. Moreover, freezing rates from 26.37, 28.91, and 33.97 ° C /h had some charac teristic with Nile tilapia quality. Freezing loss, drip loss and cooking loss was lower when the rates were high. Physical and chemical parameters were not changed with the freezing rates, but number of total viable bacteria reduced in each condition signi ficantly. Sensory score determined quality of the frozen fillets, and it was the highest in the fastest freezing rate. Lastly, implementation of temperature traceability within storage or processing can be achieve d by using wireless sen- sor networking for m onitoring temperature and humidity in storage condition.