Abstract:

The purpose of this research was to explore a new method to predict the shelf-life of tilapia. This study
investigated the quality of vacuum-packed tilapia fillets by monitoring the changes in texture, pH, conductivity, aw and total
volatile basic nitrogen (TVB-N) value when stored at -5, -20 and -40 ℃ for different periods of time, respectively. The
Pearson correlations between the changes in texture parameters and those in quality parameters were analyzed. According
to the results, cohesiveness and springiness were selected as the optimal indicators of the quality changes and shelf-life for
frozen vacuum-packed tilapia fillets. The present research showed that cohesiveness up to 0.20 or springiness up to 0.65 was
the end of fish shelf-life; the first order kinetics equations between either cohesiveness or springiness and storage time was
established as well as the Arrhenius kinetics equations describing the rate constants for the changes in both texture parameters
as a function of storage temperature. The reaction activation energy Ea was 53.532 kJ/mol, and the pre-exponential factor
k0 was 215.64 based on cohesiveness; the Ea was 89.866 kJ/mol, and the pre-exponential factor k0 was 1 620.68 based on
springiness. From experimental results, the shelf-life of tilapia fillets stored at different temperatures was estimated and the
measured values were in the acceptable range as compared with the real values. Therefore, the cohesiveness and springiness
of frozen tilapia fillets could be used to predict their shelf-life.

Key words: frozen tilapia fillets, shelf-life, texture, kinetics model, Arrhenius equation