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.