Insolubilization frozen storage

According to Caboni, it is important to carry out HPLC analyses of the purified PL fractions without frozen storage, because the latter operation leads to selective insolubilization of some components, especially PE (32). 

Connell has proposed that insolubilization of actomyosin during frozen storage of cod muscle is attributable to the denaturation of myosin rather than actin (89). During 40 weeks storage at -14°C, extractability of actomyosin and myosin decreased in parallel, while that of actin appeared to remain constant. The decrease in extractability of myosin was biphasic, while that of actomyosin followed an exponential curve. 

These results led to the conclusion that denaturation and/or insolubilization of actomyosin and myosin during frozen storage is a result of aggregation caused by the progressive increase in intermolecular crosslinkages due to formation of hydrogen bonds, ionic bonds, hydrophobic bonds and disulfide bonds. 

Figure 7. Increase in the insolubilization of soybean protein during frozen storage at —5°C by the addition of small amounts of mercaptoethanol (ME), indicating the promotion of a sulfhydryl/disulfide interchange reaction by a disulfide bond splitting agent (lOj...

Japanese Society of Food Science and Technology Figure 13. Comparison of rates of insolubilization during frozen storage between soybean protein solutions frozen immediately after preparation (heated and unheated) and frozen after 2 days of storage (heated and unheated). The heated samples were held at 100°C for 5 min prior to freezing ( ll). 

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