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The aim of this investigation was to study the influence of freezing and frozen storage on properties of protein isolates obtained from rohu and pangas processing waste through pH shift processing (pH 2.0 and 13.0). Quality changes were measured for a period of 3 months at −18°C. Increase in storage period decreased the myoglobin content, pigment content, and cooking yield (p <.05). Increase in frozen storage period increased thiobarbituric reactive substances to a range of 4.09–4.98 mg MAD kg−1. L* values of isolates decreased with the advancement of storage time (p <.05). Quality of protein gels was also affected by freezing and frozen storage. At the end of the storage period, pangas acid, pangas alkali, rohu acid, and rohu alkali isolate gels had folding test scores of 2.0, 1.0, 1.0, and 1.0, respectively. Gel strength values also decreased significantly from 1131.36, 1001.80, 847.57, and 746.88 g cm to 325.63, 226.77, 224.98, and 203.95 g cm for pangas acid, pangas alkali, rohu acid, and rohu alkali isolates, respectively. The effect of frozen storage was found to be high on pangas alkali isolate, which was evident by the drastic fall of G' and G" values (p <.05). [ABSTRACT FROM AUTHOR]