Retardation of post-mortem changes of freshwater prawn (Macrobrachium rosenbergii) stored in ice by legume seed extracts

Meat quality of freshwater prawn (Macrobrachium rosenbergii) treated with soybean and bambara groundnut extracts at different concentrations was monitored during 10 days of iced storage. During storage, the control sample (without treatment) had a higher pH, TCA-soluble peptide content, heat soluble collagen content, proteolytic activities and psychrophilic bacterial count than did samples treated with soybean and bambara groundnut extracts. Conversely, shear force value and likeness scores of the control sample decreased (p<0.05), more likely associated with softening of muscle. The decrease in myosin heavy chain in the control sample was found after 6 days of storage. However, no changes in protein patterns of samples treated with soybean extracts at 2.5 mg/mL were found after 10 days of storage. Therefore, the injections of legume seed extracts, especially soybean extract, at a sufficient concentration, could be a means to retard muscle softening and maintain the qualities of freshwater prawn during iced storage.