かまぼこの足について-XII

“もどり”の現象

抄録

A sticky paste, prepared by braying fish meat with 2 or 3% NaCl, turns to a tough and elastic gel, “kamaboko”, on cooking processes, such as steaming, boiling, or broiling.
It has been experienced that if the processes are unsuccessfully conducted rather fragile gels sometimes yield. In the previous paper, the authors showed that in such cases the paste should be kept for a long time at a temperature range between 50°C and 60°C., the kamaboko gel lost its elasticity and became fragile.
In the present study, such phenomenon, the collapse of gel structure during cooking, was observed. Samples used were lizard fish meat paste packed in Kurehalon tubus of diameter 3cm. (Kureha Kasei Co., Ltd.), and the cooking was made in water bathes kept at various temperatures. Gel-strength was evaluated by the magnitude of the tensile strength of a ring-shaped specimen (Fig. 1) and also the score values obtained by an organoleptic test in 10-point scale. Results are summarized as follows:
(1) Lowering in the gel-strength during cooking occurred at higher temperatures than 50°C., favourably near at around 60°C. and again at 90°C. (Fig. 2).
(2) Washing process on the raw chopped meat, by which a greater part of the water soluble matters was removed, raised the kamaboko-forming capacity of the meat paste, but had little effects on the change in gel-strength at 60°C. (Fig. 3). This may suggest that the water-soluble matters in the paste play a minor role in this phenomenon.
(3) Meat pastes brayed of aged meat (stored for 5 days at 4°-5°C.) were more easily subjected to the heat influence at 60°C. than those of fresh meat (Fig. 3).
(4) Initial pH of the paste seemed to have no significant influence on the occurrence of the phenomenon (Fig. 4).
(5) Stability of the kamaboko gel to heating at 60°C. was quite different with the conditions, under which the paste had been kept prior to the cooking. Gels produced by pre-cooking at 80°C. and 90°C. for 20minutes did not change their strength even after heating for long time at 60°C., while those pre-cooked at lower temperatures than 70°C. were significantly damaged on the gel structure (Fig. 5).