Abstract
Shelf life of fresh and frozen fish is an important subject for marketing and the extension
of shelf life and maintenance of quality is essential for allowing the market to obtain good profitability. Adding one or two days to the product, shelf life allows the market to obtain good profit margin and assure repeat sales. In selling fish, the shelf life has a high consideration, calculating the remaining shelf life helps a fisherman, processor or retailer
to plan the length of time a product can be held, allowing control of the market. Shelf life determination is very essential because it indicates the time of storage of fish in iced condition, till the time the fish remain edible for the consumer. The present study implies different techniques of extending post-harvest shelf life of cage reared marketable tilapia (Oreochromis niloticus) during ice storage. The shelf lives of haor-cage and pond reared tilapia in ice stored condition were studied and compared to assess
these two different environmental effect on physical composition, quality and shelf life. Tea (Camellia sinensis) extract and pomegranate peel (Punica granatum) extracts were incorporated with ice to assess their efficacy as natural fish preservative in extension of shelf life of tilapia during ice storage. Commercial probiotics were added with feed and applied to culture system to assess the effect of probiotics in improving quality and extending shelf life of tilapia. The shelf life of tilapia storing in styrofoam (cork sheet)
fish box (SFB) and tank ice box (TIB) were studied and compared to assess the capability
of these two frequently used fish boxes in maintain quality and extending shelf life. The shelf life of tilapia in ice stored condition was assessed by applying sensory
characteristics (quality index method), biochemical parameters (pH, TVBN), microbiological changes and proximate analyses (crude protein, crude lipid, moisture
and ash). Different culture environment influenced the physical composition, quality and shelf life of tilapia. The shelf lives of haor-cage and pond reared tilapia was found to
be 12 and 15 days, respectively in ice stored condition. Tea extract and pomegranate peel
extract incorporating with ice extended shelf life of tilapia for 8 and 6 days, respectively
in ice stored condition in comparison to normal icing. Probiotics treatment extended shelf life of tilapia for 2 days in ice than normal icing. The shelf lives of SFB and TIB stored tilapia were found to be 12 and 18 days, respectively in ice stored condition and additional shelf life of 6 days was noticed in TIB in comparison to SFB. The values of quality index (QI) score, biochemical parameters (pH, TVBN) and total viable count TVC) were found to be increased with the increased storage period in ice. The percentages of crude protein, crude lipid and ash were found to be decreased during storage period. The information about the shelf life of tilapia from different culture environment would help the fishermen, seller and consumer to be aware of the shelf life and would help the industry to supply safe, high-quality and health promoting tilapia ish-product. The information obtained from this study of extending shelf life of post- narvest marketable tilapia demonstrated a better efficient method of fish preservation.
The present findings would be useful in leading to further experiments on the dentification and characterization of natural sources that are responsible for extending quality of food products. The extension of shelf life for a significant period of time could
pe useful to fish consumers, fish traders and nutritionists in the efficient management of ish products.