Effect of smoking technologies on nutritional quality and concentration levels of polycyclic aromatic hydrocarbons (PAHs) in Mormyrus caschive and Oreochromis niloticus were determined to enable adoption and utilization of suitable facility that maintains good quality for sustainable supply of nutritious fish products in South Sudan. A total of 72 fresh M. caschive and O. niloticus were purchased, of which 24 were iced for reference and the other 48 were divided into two groups for pit and chorkor smoking. Experimental smoking of fish samples was conducted twice in a randomized design. Fish samples were analyzed for nutritional values using standard methods of the association of official analytical chemists and levels of PAHs using gas chromatography-mass spectrometry. Results revealed; the two smoking methods concentrated crude protein, fat and ash contents. However, fish smoked using chorkor had significantly higher nutritional values than fish smoked using pit kiln. About seven types of PAHs comprising of low and medium molecular weight were recorded from the two smoked fish species. Naphthalene and fluorene were the two dominant PAHs with fish smoked using pit kiln having significantly higher concentration levels of naphthalene (5.86±4.16 µg/kg) and fluorene (3.83±0.10 µg/kg) than fish smoked using chorkor oven. The study concluded that chorkor oven has better quality smoked fish than pit. Hence, its utilization and adoption for artisanal fisheries in South Sudan is recommended.

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Background: Lysine is one of the essential amino acids required in the human diet. However, it is easily lost when fish is subjected to different processing methods which may compromise the human dietary requirements. Methods:We determined changes in lysine content of four fresh water fish species, namely Bagrus docmak, Rastrineobola argentea, Brycinus nurse and Distichodus niloticus. The fish were obtained from lakes Victoria, Kyoga, Edward and Albert in Uganda. Lysine was determined before (baseline) and after processing the four fish species using artisanal methods, namely sun-drying, salting, smoking and deep-frying. Results:The baseline lysine content varied significantly among fish species (6.1-17.6%). Lysine content of B. docmak from L. Victoria and Rastrineobola argentea from L. Kyoga reduced significantly by 43.2 and 55%, respectively, when deep-fried. Smoking also significantly reduced lysine content in R. argentea by 50%. Distichodus niloticus occurs in only L. Albert, and its lysine content decreased with processing method by 49.5% in deep-fried and 7.3% in sun-dried. Processing method did not significantly change lysine content of Brycinus nurse.Conclusion: Generally, the nutritional quality with regard to lysine content of four fish species was not significantly affected by three artisanal processing methods: drying, salting and smoking. However, deep-frying significantly reduced lysine content in three species which has a bearing on public health. In this regard, awareness creation among processors and consumers about deep-fried fish products would alleviate the nutritional insecurity attributed to deep-frying. In addition, modification of the existing artisanal processing methods is necessary to avert a possible predisposition to lysine deficiency.