CHANGES IN PHYSICOCHEMICAL PROPERTIES AND SHELF LIFE ABILITY OF KUTUM (RUTILUS FRISII KUTUM) SLICES DURING PACKAGING AND STORAGE IN ICE YASAMAN ETEMADIAN and BAHAREH SHABANPOUR 1 Faculty of Fisheries Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran 1 Corresponding author. TEL: +98-171-2245965; FAX: +98-171-22425886; EMAIL: bshabanpour@yahoo.com Accepted for Publication April 15, 2012 doi:10.1111/j.1745-4549.2012.00760.x ABSTRACT Under normal refrigerated storage conditions, the shelf life of fish products is limited by enzymatic and microbiological spoilage, so in this study applied methods like vacuum packaging with a cryoprotectant agent. Results of fresh Rutilus frisii kutum slices packed in vacuum with a cryoprotectant agent (sodium tripolyphosphate) and under ice storage conditions showed higher water holding capacity and a reduction of sulfhydryl groups’ oxidation. Thiobarbituric acid, total volatile base-nitrogen contents and psychrophilic bacterial count in samples treated with sodium tripolyphosphate and under ice storage conditions decreased during ice storage (P < 0.05). The pattern of gel electrophoresis did not show con- siderable difference between all treatments with increase in storage time. In total, the final results based on sensory evaluation and bacteria counts concluded that the shelf life of fresh kutum slices packed using vacuum packaging and sodium tripolyphosphate was longer than the shelf life of fresh kutum slices packed using only with a cryoprotectant agent. PRACTICAL APPLICATIONS We test changes in the level of information about phosphate effects with vacuum pack. Use of polyphosphates with vacuum packaging can cause more quality in foods. Polyphosphate treatment with vacuum packaging will increase water holding capacity. Polyphosphates are legally additives that use for improve eating quality of foods. INTRODUCTION Fish and other marine species give rise to products of great economic importance in many countries (Aubourg and Ugliano 2002). During processing and storage, fish quality may decline in result of several factors. One of the most important of them is the oxidation of highly unsaturated lipids (Ackman 1989), which is directly related to the pro- duction of off-flavors and odors. (Hsieh and Kinsella 1989). Inorganic polyphosphates are generally recognized as safe food additives and are widely used in the meat and dairy industry to enhance major functional properties (Akhtar et al. 2008). Also, the use of vacuum packaging and other methods to extend the shelf life of a large number of food products has been of great interest to many scientists during the last year. However, the shelf life extension of fish pro- ducts has remained problematic, owing to the high perish- able nature of these products. Because of this, some researchers have tried to use vacuum packaging and other preservation methods to extend the shelf life of the packed fish. Shakila et al. (2005) studied the shelf life of seer fish chunks under vacuum packaging, Ozogul et al. (2004) evaluated the shelf life extension of sardines (Sardina pil- chardus) under modified atmosphere packaging conditions, Manju et al. (2007) studies effects of sodium acetate dip treatment and vacuum packaging on shelf life of pearlspot (Etroplus suratensis) during chill storage and Alvarez et al. (1996) evaluated the shelf life extension of hake slices treated with sodium tripolyphosphate under modified atmosphere packaging conditions. In this article, the overall Journal of Food Processing and Preservation ISSN 1745-4549 1 Journal of Food Processing and Preservation •• (2012) ••–•• © 2012 Wiley Periodicals, Inc.