Program and Abstracts(PDF)

IMP changes the taste quality of Val in vivo. In addition the content of Val in mature and
immature gonads (which are edible part) of sea urchin, Hemicentrotus pulcherrimus were
examined. Val was 60-100mg/100g and its content was only 3-5% of total amino acids in the
gonads. Thus there is no difference between mature and immature, also ovary and testis.
Murata, Y. and Unuma, T. 2009. Concentration of Val, Met and IMP in gonads of seven edible
species of sea urchin in Japan. Jpn. J. Taste Smell Res. Vol.16, Pp 445-446.
(Japanese)
Valine (Val) and Methionine (Met) have a bitter and slightly sweet taste for humans and
contribute to the taste of sea urchins (Komata, 1964). In a previous CTA experiment with
C57BL/6J mice, the results suggested that the taste quality of Val and Met changed to have
umami after mixing with IMP. Also the concentration of Val in Hemicentrotus pulcherrimus
gonads was examined. In Japan, there are 7 species of sea urchins that are mainly eaten. The
taste of gonads differs among these species, however there are no scientific data to prove it. In
order to clarify the cause of this difference we investigated the concentration of Val, Met and
IMP in gonads from these 7 species of sea urchin. The content of Val and Met ranged
7~70mg/100g and 2~26mg/100g, respectively, and accounted for under 5% of total amino
acids in the gonads of each species. The content of IMP was the same level as Met, ranging
1.2~26mg/100g. These data suggest that the small content of Val and Met may contribute to a
pleasant bitterness and small content of IMP may change the taste quality of amino acids in
the gonads of each species of edible sea urchin.
Murata, Y., Okazaki, E., Kimura, M., Imamura, S., Hiraoka, Y., Kimura, I. 2010. Gel forming
ability and freeze tolerance of ground fish meat with a high content of ATP. Journal of
Fisheries Technology. Vol.2, Pp 105-110. (Japanese)
Muscle from horse mackerel was ground with a cutter mill immediately after instant killing to
prepare ground meat with high contents of ATP. The ATP level was kept high about 70% until
90 seconds after the grinding started. For comparison, the meat with high ATP was stored at
5℃ for 6 hours to prepare one with a low content of ATP. The ground meat with high ATP was
able to form a strong gel by addition of 3% or lower concentrations of NaCl. After storage at
-20 and -80˚C for 2.5 months, it formed a smooth gel by addition of NaCl and solubility of
myofibrilar proteins was higher than that of the ground meat with low ATP. A gel forming
ability of the ground meat with low ATP recovered to the same level of that with high ATP
after addition of ATP. These results suggest that it is important to keep the level of ATP in
ground fish meat at certain level for its gel forming ability and freeze tolerance.
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