Effects of different heating methods on the contents of nucleotides and related compounds in minced Pacific white shrimp and Antarctic krill

Abstract

The effect of heating methods (microwave and water bath, and combined microwave and water bath heating) on 6 nucleotides and related compounds (NRCs) in minced Pacific white shrimp and Antarctic krill was investigated at 25, 40, 55, 65, 75, 85, and 95 °C. In Pacific white shrimp, the main changes of NRCs were in adenosine monophosphate (AMP) and inosine monophosphate (IMP). High temperature (85 and 95 °C) can inhibit the ATP degradation by water bath heating. In Antarctic krill, the main change of NRCs was in inosine (HxR) that decreased in microwave heating treatment at 95 °C. The different methods were compared in terms of IMP content and flavor/bitter ratio, which are related to flavor of aquatic products. The best heating method was pre-heating at 75 °C in water bath followed by microwave heating at 95 °C (IMP content and relatively flavor/bitter ratio were 4.34 μmol/g and 3.00, respectively) for pacific white shrimp and pre-heating at 65 °C in microwave followed by water bath heating at 95 °C (IMP content and relatively flavor/bitter ratio were 0.18 μmol/g and 0.06, respectively) for Antarctic krill, respectively. Chemical analysis, microbiological analysis and sensory evaluation showed that the K value is not suitable for assessing the freshness of Antarctic krill.