Condition‐dependent adenosine monophosphate decomposition pathways in striated adductor muscle from Japanese scallop (Patinopecten yessoensis)

Abstract

The purpose of this study was to confirm inosine monophosphate (IMP) generation and to clarify the decomposition pathway of adenosine monophosphate (AMP) by investigating the properties of AMP, IMP, and adenosine (AdR) decomposition enzymes in Japanese scallop (Patinopecten yessoensis). The results showed that IMP accumulated due to AMP decomposition via endogenous enzymes in scallops stored at both 4 °C and 20 °C. The AMP decomposition rate was highest in the supernatant of homogenized scallop adductor muscle, followed by the suspended solution and precipitate, while IMP could not be decomposed in scallop. The results indicated that the activity of AdR deaminase was very high, and this enzyme was involved in an intracellular process in scallop. Moreover, 1 min of heating exerted little influence on the AMP and AdR decomposition rates, while 5 min of heating induced enzyme denaturation. The IMP generation rate increased dramatically in scallop crude enzyme solution containing 5 mM ethylenediaminetetraacetic acid (EDTA). This suggests that the major pathway of AMP decomposition might change with variations in metal ion concentrations in Japanese scallop.Practical ApplicationIMP generation in Japanese scallop (Patinopecten yessoensis) caused by endogenous enzymes was confirmed. IMP is very important for the umami taste (a pleasant savory taste) of aquatic products. As IMP accumulation might be achieved by changing the concentration of divalent metal ions and no IMP 5’‐nucleotidase activity was detected in scallop, a suitable process to produce good flavor scallops with high IMP contents might be developed.

Differentiation between fresh and frozen‐thawed scallop adductor muscle as raw materials for sashimi during cold storage

“…AMP was converted to inosine (HxR) and then to hypoxanthine (Hx) during cold storage while the production of HxR and Hx correlates with a loss of freshness in some fish species (Ocaño‐Higuera et al., 2011). As it was reported that there are two AMP decomposition pathways in scallop striated muscle, the conversion of AMP to HxR via adenosine (AdR) or IMP and the AdR pathway is faster (Wei et al., 2020b). Once AdR was produced, it will be immediately decomposed to HxR and Hx so that the existence of AdR can hardly be detected.…”

Determination of Adenylate Nucleotides in Amphipod Gammarus fossarum by Ion-Pair Reverse Phase Liquid Chromatography: Possibilities of Positive Pressure Micro-Solid Phase Extraction

“…Ultrasonication usually requires more sonication cycles, and it can cause a substantial increase in local temperature of the sample media. Hydrolysis of ATP, ADP, and AMP due to temperature increase was noted in several studies [30][31][32]. Recently, global molecular profiling was used for investigation of the effect of heating on small molecules such as triphosphate nucleotides (ATP, UTP, and GTP).…”

Mitochondrial activity as an indicator of scallop (Mizuhopecten yessoensis) adductor muscle in early cold storage

“…During 0−12 h cold storage, mitochondria still produce ATP, the level of ATP had no significant change. During 12-48 h, mitochondrial activity was greatly reduce, hydrolysis of ATP could produce large amounts of IMP and AdR, and although IMP could not be decomposed in scallop, and no large amount of HxR and Hx were gener- (Wei et al, 2020), resulting in rapid increase of K value. ArP, as the phosphagen scallop adductor muscle, is converted into ATP for rapid supplementation and consumption during the severe exercise of scallops (Grieshaber, 1978).…”