Abu-Tor,, E. (2002). QUALITY CHANGES AND SHELF - LIFE OF HOT SMOKED FISH FILLETS. Journal of Food and Dairy Sciences, 27(10), 6847-6861. doi: 10.21608/jfds.2002.256866
EL-S. M. Abu-Tor,. "QUALITY CHANGES AND SHELF - LIFE OF HOT SMOKED FISH FILLETS". Journal of Food and Dairy Sciences, 27, 10, 2002, 6847-6861. doi: 10.21608/jfds.2002.256866
Abu-Tor,, E. (2002). 'QUALITY CHANGES AND SHELF - LIFE OF HOT SMOKED FISH FILLETS', Journal of Food and Dairy Sciences, 27(10), pp. 6847-6861. doi: 10.21608/jfds.2002.256866
Abu-Tor,, E. QUALITY CHANGES AND SHELF - LIFE OF HOT SMOKED FISH FILLETS. Journal of Food and Dairy Sciences, 2002; 27(10): 6847-6861. doi: 10.21608/jfds.2002.256866
QUALITY CHANGES AND SHELF - LIFE OF HOT SMOKED FISH FILLETS
Department of Food Science and Technology, Faculty of Agriculture, EI· Chatby, Alexandria University, Alexandria, Egypt.
Abstract
Hot smoked Kapreeta (Scombromorous sp < /em>.) fish fillets packed in laminated films- double layers (treated foil/ polyethylene) bags sealed under vacuum were used in this study. Data on changes occurring in the quality and shelf-life and spoilage rates during storage at ambient temperature (25-28 °c ),chilled storage (0 to 2 0c) and refrigerated storage (10 :t 2°C) are presented.
A method of presenting the data to allow decisions to be taken on the shelf - life of chilled and refrigerated products is discussed. The results obtained are as follows:
1- Initially the fillets were golden brownish in colour, showed signs of desiccation after <6, 35, 49 days storage at 25-28 °c, 10°C and 0-2 DC; respectively which increased in further storage and the fillets finally became dull brown with yellow discoloration inside. The firm and juicy texture of the smoked fillets changed to rubbery and soft at the end of the storage period. The rate of spoilage at room temperature (RT), therefore, approximately 5 and 7 times greater than at refrigerated and chilled storage, respectively.
2- The chilled and refrigerated smoked fillets recorded the least, and the fillets stored at room temperature, the highest values of all the indices of quality attributes namely, free fatty acids (FFA), thiobarbituric acid (TBA) , peroxide value (PV), total volatile basic nitrogen (TVB-N), trim ethyl amine (TMA) and alpha amino nitrogen. Total viable counts, moulds & yeasts, hallophilic and psychrotrophic bacteria number also showed a similar trend.
3- At 0-2 °C, The FFA increased from 0.65% (as oleic acid) to 1.5%, the TVB-N from 6.50 to 33 mg/100g. The TBA, PV and TMA values also showed a similar trend of increasing. However, alpha amino nitrogen decreased from 50.60 to 20mg/1 ~Og. The moisture content showed a similar trend.
4- The bacterial metabolic end products (TVB-N and TMA) were less useful as objective measurements of freshness, whereas it could be used as an
indicator of the onset of bacterial spoilage. -
5- The pH was not a good indicator of early storage changes, TBA, PV and FFA could be used to determine loss of acceptability or end of shelf-life. Moreover, it showed correlation with taste panel results.
6- Smoked kapreeta fish (Scombromorous sp.) fillets could be kept in good quality up to 7 weeks if the temperature is maintained below 2°C. Fluctuating and high temperature in the cold stores are the limiting factors in the quality of fish products.