Shelf life studies in fresh and processed freshwater fish

The aim of this study was to evaluate as objectively as possible the freshn ess of five different fish products, i.e. fresh fish, smoked fish, marinate d fish, fish salad and fish balls, which were all stored vacuum packed as w ell as not packed. Besides the kind of packaging, the storage temperature h as to be considered as one of the main shelf-life determining factors. With constant storage conditions the limit of fitness for consumption was reach ed for vacuum packed roach (Rutilus rutilus) on day 5 and for whitefish (Co regenus spp.) on day 7 when stored at + 7 degreesC, while at + 2 degreesC t he limit was on day 8 for whitefish. Not packed whitefish were not fit for consumption from the 3rd day of storage (at + 7 degreesC), respectively the 5th day of storage (+ 2 degreesC). The shelf-life of vacuum packed smoked white fish was determined as one to two weeks (+ 7 degreesC), respectively three weeks (+ 2 degreesC). Marinated fish remained fit for consumption for three to four weeks when stored at + 7 degreesC and for four to six weeks at + 2 degreesC. The salads showed a shelf-life of three to four weeks at 7 degreesC and of up to five weeks at + 2 degreesC. Vacuum packed fish bal ls were fit for consumption up to 30 days whereas those wrapped in paper ke pt for six or eight days. The applicaton of sensory tests for the examination of the freshness of vac uum packed and not packed fish products allowed the assessment of the fitne ss for consumption with sufficient reliability. Additional microbiological examinations in combination with chemicophysical tests can be recommended, as the former are anyway indispensible to determine the hygienic and microb iological quality of the products.