Shelf life assessment of hot smoked African catfish stored under different storage conditions from Lake Kenyatta, north coast, Kenya

Abstract

Catfish (Family Clariidae) from Lake Kenyatta in coastal Kenya was smoked using an improved smoking (Chorkor) oven and subjected to storage under different packaging conditions. Biochemical, proximate composition and sensory parameters were used to determine the shelf life of the product for a period of 30 days. Peroxide values for samples stored under open, ambient air, and vacuum packaging increased significantly (p < 0.05) from 7.296 megO₂/kg to 24.890 meqO₂/kg, 28.940 meqO₂/kg and 18.729 meqO₂/kg, respectively. Thiobarbituric acid reactive substances increased from 0.459 mg/kg to 4.653 mg/kg, 1.473 mg/kg and 0.339 mg/kg during storage under open, ambient air, and vacuum packaging, respectively. Total volatile bases-nitrogen increased significantly with storage days, from 1.349 mgN/100g to 5.182 mg N/100g, 6.700 mgN/100g and 2.001 mgN/100g for open, ambient air, and vacuum packaging, respectively. During storage, proximate composition for the stored samples differed significantly between the open and ambient air package only, while sensory changes were observed on day 30 only. Texture remained the same to day 30 for all samples stored under difference storage conditions. Water activity ranged between 0.7 and 0.79 during the same period in the three packaging conditions. In general, the 30 days storage period did not compromise the acceptability of smoked products.