魚肉ねり製品の研究-XIX

生魚肉の吸水率と塩溶性蛋白質量に及ぼす塩類濃度の影響

抄録

As already reported, OKAMURA found that water affinity of fish flesh as appraised by the factor of water intake he proposed was reduced to a minimum by a certain small addition of salt.
In the present work, the authors, employing a refrigeratory centrifuge improved in enabling said factor to be measured even in hot summer days, made again certain of the above OKAMURA's disclosure and further determined the salt concentration which suppressed the protein solubility of fish flesh to a minimum. The results obtained are summarized as follows:
i) By means of said refrigeratory centrifuge, determination of the factor of water intake can be carried out quite neatly without causing denaturation even in summer; statistical error range of the present method was less than 8.2% as the factor of water intake, the factor of water intake being evaluated on 5 % significance level.
ii) In perfect agreement with the OKAMURA's proposition, a salt such as NaCl, MgCl₂, MgSO₄, K-phosphate^†, Na-pyrophosphateft^††, and Na₃-citrate, at a certain concentration according to his previous definition reduces the factor of water intake to a minimum value (†: Equimolar mixture of K₂HPO₄ and KH₂PO₄ ††: Na₄P₂O₇ was used after neutralization with HCl.).
iii) While the amount of soluble protein in centrifugal supernatant is also minimized at a certain salt concentration, this concentration is somewhat lower than that which corresponds to the minimum of the factor of water intake.