Water holding capacity (WHC) of myosin-fraction (“M”) gel was determined under varied pH conditions by centrifugal method (8, 000rpm, 20 min.).
1. WHC of “M” gel is greater than that of muscle homogenate, being maximum in isoelectric zone in contrast with the latter which is minimum in this region.
2. WHC of isoelectric “M” gel decreases if pH is shifted to ?? 4.5 or ?? 8. Similarly decreases WHC of “M” gel formed in the alkaline side on readjustment of pH to ?? 4.5.
3. If pH of “M” gel formed in acid or alkaline side is brought to isoelectric zone, WHC is not only less than that of isoelectric gel, but also of the original gel.
4. If pH of isoelectric or alkaline gel is brought to ?? 4.5, WHC of the reformed gel is smaller than that of gel formed at pH ?? 4.5.
Results 1 and 2 might be interpreted by an assumption that firmness of structure sufficient to hold water against pressure applied in measurement of WHC has a decisive influence on WHC in the case of gels with relatively weak structure as “M” gel. In Result 3 WHC decreases, though the structure of reformed gel is supposed to be thickened by pH adjustment. This might be probably due to that syneresis has more pronounced effect than firmness of structure. Result 4 can not be explained either by loosening of structure nor syneresis.