Content Variations of ATP-Related Compounds and Quality Assessment of Tilapia Fillets during Iced Storage

Abstract

To explore the biochemical changes of tilapia fillets during iced storage, contents of adenosine triphosphate (ATP) and its degradation products were monitored by high performance liquid chromatography (HPLC), along with ATPase and the freshness indicators such as the values ofK,Ki,H,Fr, total volatile base nitrogen (TVB-N) and thiobarbituric acid (TBA) were determined to evaluate the quality of iced tilapia fillets. The results showed that ATP, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in iced tilapia fillets degraded sharply into inosine monophosphate (IMP) at the first day of storage, then almost kept stable in a low level over the rest of iced storage time. Meanwhile, IMP degraded into hypoxantjine (Hx) and inosine (HxR) with the extending storage time, and Hx as well as HxR accumulated. The changes of values ofK,Ki,H,Frwith iced storage time presented a significant linear correlation (P<0.01, r=0.945, 0.943, 0.924, -0.943, respectively). ATPase activities were associated with the degradation of ATP. The contents of IMP, Hx, HxR, values ofK,Ki,H,Frand ATPase activities can be used as practical and effective indicators for quality assessment of tilapia fillets during iced storage instead of TVB-N and TBA.