Performance and quality assessment of smoke curing of Bairn (Mastacembelus pancalus), Kaika (Xenentodon cancila) and Chapila (Gudusia chapra)

Abstract

Present study implies different techniques of smoke-drying to preserve three freshwater small indigenous species (SIS) of fishes of Bangladesh viz ., chapila (Gudusia chapra), kaika (Xenentodon cancila) and baim (Mastacembe/us panca/us) using smoke curing method . Smoke curing of chapila , kaika and baim fish was conducted in an improved type of traditional smoking kiln by using tamarind wood chips and rice husks as smoke Source . The experimental chapila, kaika and baim fish samples were treated with four different treatments namely, Unsalted (US), Salted (S), Salt+ Turmeric (S+ T) and Salt+Garlic (S+G) . Performance, quality assessment and shelf life study of the smoke-dried chapila, kaika and baim fish products were done . This study assessed the comparative changes in sensory characteristics, microbiological quality , water reconstitution time and biochemical aspects of fresh and smoke-dried freshwater SIS fish, chapila, kaika and baim during storage at room (26-31 dc) and refrigeration (4 D C) temperature using standard methods of analyses . In fresh process condition water reconstitution rate was faster in salt treated (S) smoke-dried chapila , kaika and baim fish products but slower in Unsalted products . Remarkably kaika fish exhibited an enormOUSly rapid initial rate of reconstitution . Important mineral composition e.g. Ca , Mg , Fe, Zn , Cu and Mn were also determined in fresh fish and fresh smoked fish products and found that smoke-dried fishes is a good source of minerals . Results of the freshly collected chapila , kaika and baim fish had been found to contain moisture, protein, fat , ash, TVB-N and TVC 76.41±0.02%, 10.53±0.03%, 11.62±O.03%, 1.50±O.03% , 2.40±O.03 mgN/100g and 3.1x105 cfu/g ; 77 .67±0.03% , 14.27±O.03%, 4.66±O.01% , 2.94±O.04% , 4.92±0.04 mgN/100g and 4.1x105 cfu/g and 77.21±O.08%, 15.17±0.03% , 6.13±0.03%,1.72±O.03% , 3.16±0.02 mgN/100g, and 5.8x104 cfu/g respectively. After smoke-drying moisture (%) and TVC (cfu/g) decreased whereas protein (%), fat (%), ash (%) and TVB-N value (mgN/100gm) increased in the smoke­ dried fish samples when compared to fresh fish samples . Salt (NaCI) content in the freshly prepared smoked products ranged between 2.87 and 3.75 %. During storage at room and refrigeration temperature the percentage of moisture, TVB-N value (mgN/100g) and TVC (cfu/g) was increased whereas protein, fat ash and salt content were found to be decreased . Direct relation was observed between moisture and TVB-N and moisture and TVC whereas inverse relation was revealed between sensory score and TVB-N value. However, there was also a general decline in sensory characteristics and scores on color, odor, texture , general appearance and mean of general acceptability score of all the smoke-dried fish products as storage duration XIX increased and the acceptability score <3.5 was considered as rejected or spoiled for all the smoke-dried fish samples . On the other hand mineral elements were detected in the decreasing order of Ca followed by Mg , Fe , Zn , Cu and Mn in fresh fishes. The shelf life of US , S, S+ T and S+G treated smoke-dried chapila, kaika and baim fish products varied considerably during storage at room and refrigeration temperature. From the overall performance , smoke-dried baim fish showed better shelf-life than smoke-dried chapila and kaika fish . However, all the smoke-dried fish products stored at refrigeration temperature (4°C) showed a longer shelf life (except S+ T treated Kaika) than room temperature (26-31 o C) . The highest shelf life was found to be 27 months in case of ' S+ l' treated smoke dried baim fish with all its sensory qualities as good conditions during storage at refrigeration temperature . On the contrary the lowest shelf life was observed in 'US ' smoke dried chapila, kaika and baim fish products. Among the three fish species , 'US ' smoke dried chapila and kaika fish were found lowest shelf life and the duration was 4 months during storage at room temperature . The information obtained in this study of smoke curing demonstrated a better efficient method of fish processing in terms of the retention of protein value having good sensory scores and reduction in the moisture content which could be useful to fish consumers, processors and nutritionists in the efficient management of fish resources by increasing its shelf life for a significant period of time.