Studies on the control of denaturation of fish muscle proteins during frozen storage. VI. Preventive effect of carbohydrates.

The preventive effect of carbohydrates on freezing denaturation at -30°C for 4 to 7 weeks was examined by using an in vitro model test system of the isolated carp actomyosin. The rate of denaturation was followed by estimating solubility, viscosity, ATPase activity as well as the degree of superprecipitation. The overall results can be summarized as follows: Additives exhibiting marked effect: glucosse, fructose, sucrose, lactose, melezitose, stachyose, glycerol, ethylene glycol, sorbitol, gluconic acid, glycolic acid, β-glycerophosphate, fructose-6-phosphate and glucose-1-phosphate. Additives displaying moderate effect: xylose, ribose, raffinose, inulin and erythritol. Additives with little or no effect: glyoxal, dihydroxyacetone, mannitol, starch, ascorbic acid and glucuronic acid. The preventive effect of tested additives was generally in agreement with the reported results with other substances such as red cells, bacteria, etc. The results suggest that the protection mechanism involved might be common with the different substances and thus be related with nonspecific bondings such as hydrogen bonding. It was also suggested that the influence of the amino carbonyl reaction should be considered.