Effect of smoking and oven-drying on shelf stability and sensory properties of antic mackerel fish fillets

Thesis Abstract

The work was carried out to determine the effectiveness of smoking and oven drying onthe shelf stability and sensory characteristics of Atlantic mackerel fish fillets duringstorage. In the study, mackerel fish was eviscerated and cut into fillets, weighed andmeasured, cleaned and dipped in 75% saturated brine for 1 minute. It was smoked at atemperature of 60-70oC for 4hours. Products were then divided into four (4) batchesafter smoking and cooling. One batch was kept at room temperature as control whilethe remaining 3 batches were oven dried at 70-80oC for 1hour, 2hours and 3hours

respectively.

The smoked and dried fish fillets were later stored at room temperatureincluding the control (sample A) for 21days and were analyzed for physical, chemical,microbial and sensory qualities. Result indicated that moisture content and wateractivity of the products decreased as storage period increased. The thiobartituric acid(TBA) value and peroxide value increased during storage and decreased with dryingtime. It was noticed that the mould count increased with storage period but decreasedwith drying time and the same was also applicable to the total viable count. The sensoryevaluation studies showed a significant difference (p<0.05) within samples in respect ofappearance, flavour, tastes, saltiness and colours. The result of the sensory evaluation atthe later storage days gave a general preference for the 3hours oven drying sample.Based on the result obtained from the treatments a drying period of three (3) hours wasrecommended. This was because this treatment (sample D) gave a product with the bestgeneral acceptability and also gave a product of low moisture content, low water

activity and was more shelf stable.