抄録
It has been well known as a setting phenomenon that sticky paste produced when fish muscle is ground with an adequate quantity of salt, turns on standing to an elastic jelly getting rid of adhesiveness. Presence of salt is indispensable with the case. The process is deemed to involve two stages-peptization of muscle protein (myosin) and gelation of the sol thus formed. The reason why two opposite reactions, peptization and gelation can take place under the same condition, that is, in the presence of salt which may favour solvation of protein, has been left unsolved.
Intending to throw light on this problem, we have examined the iufluence of different salts on the setting of horse mackerel meat. Salt was added so as to form 0.5 mol solution when assumed to be completely dissolved in water in the meat. Results are summarized in Table 1 to 3.
Salts can be divided into three groups with respect to the effect on the setting of meat.
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Salts of alkali metals belong to either Group I or II, and exert different effects according to the kind of anions, while no appreciable differences are observed when cations differ. Speciality observable in Mg salts, acetates of alkali-earth metals, sulfates of Mn, CoII, FeII and NiII is obviously due to influences of cations. The influences of heavy metal salts are deemed to have something to do with firm and extensive formation of metal-protein complex. However we have no evidence for further interpretation of the case.
Ability of anions to cause setting is found qualitatively by organoleptic observations, to be in the following order
Cl-<Br-, NO-3<I-<CNS-
Thus presence of lyotropic series is recognized. Inversely, then, we can predict the extent of ability of anions in causing the following series with regard to volume contraction of solutions, which is a phenomenon due to hydration of ions,
CO--3>Fe (CN)-IV6>F->SO--4>H2PO-4>Cl->I->Fe (CN)-III6>CNS-
Then K4Fe (CN)6 will be expected to fail, while K3Fe (CN)6 to be very effective in making meat set. This presumption is proved actually (Tab. 3).
In conclusion, we are in an opinion that the settng phenomenon occurs when muscle proteins are strongly hydrated under the influence of anions, and that important role played by salt in this phenomenon consists in its ability to make protein hydrated.
