Cryoprotective effects of polyphosphates on Rutilus frisii kutum fillets during ice storage

Polyphosphates have profound effects on the functional properties of the food products. In this study, the effects of (2% w/v) solutions of tetrasodium pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) and a mixture of them on the shelf life of filleted Rutilus frisii kutum during ice storage were examined. Common zipper pouches were used for packing fish fillets. The packs were placed beside ice with a fish/ice ratio of 1:1 (w/w) in an insulated box and were maintained at 4 °C. The control and the treated packs were analysed periodically for chemical, microbiological (psychrophilic bacterial counts), textural and sensory characteristics. Control samples were found to have a shelf life of about 6 days, whereas samples treated with polyphosphate were found to be acceptable up to 9 days. Thus being treated with polyphosphates was found to delay the spoilage and extend the shelf life of R.f. kutum in ice.