3. EVALUATING SPECIFIC ICE MELTING RATE (K) OF INDIGENOUSLY DEVELOPED FISH VENDING AND DISPLAY UNIT AND QUALITY ASSESSMENT OF ICED INDIAN MACKEREL (RASTRELLIGER KANAGURTA, CUVIER, 1816) STORED IN THE UNIT by AMITHA,
The aim of this study was to evaluate the specific ice melting rate (k) and influence of icing on quality changes of Indian mackerel (Rastrelliger kanagurta) stored in the indigenously developed fish vending and display unit. The unit had a capacity of 224 L and dimension was 86× 45 × 58 cm (L×B×H). This unit was made out of food grade stainless steel (SS) that is inner SS 304 and outer SS 202. The insulating material used was polyurethane foam with a thickness of 1.5 inches. The insulating capacity of the unit was tested in the shade for a period of 7 days by loading crushed ice. Specific ice melting rate (K) was estimated with a regular intervals of 2 h with an average temperature of 24.5 °C. The K was observed to be 1.15 kg/h on initial day and 0.66 kg/h on the final day, indicating the rate of ice melting was 20 % per day. The influence of ice storage on mackerel was evaluated for 14 days. The ice and fishes were arranged in the unit with a ratio of 1:1 (ice: fish). Quality parameters like pH, Total Volatile Base Nitrogen (TVB-N), Trimethylamine Nitrogen (TMA-N), Peroxide value (PV), Thiobarbituric acid reactive substance (TBARS), Free fatty acid (FFA) and Total plate count (TPC) increased significantly and Alpha amino nitrogen (AAN) was decreased during the storage period (P < 0.05). The sensory scores for overall acceptability were found to be decreased significantly. This study showed that, the fish vending and display unit is effective in extending the keeping quality of fish up to 12 days in iced condition and can be recommended for marketing of fresh fish over existing counterparts in the market.
KEY WORDS: Specific ice melting rate (K) · Fish vending and display unit · Indian mackerel · Quality assessment · Ice storage.