Dried fish is a rich source of protein, lipid and minerals that can serve as a promising source of nutrients to alleviate malnutrition in low-income countries. Nowadays, fish drying is becoming an increasing practice to extend the shelf life of excess catch in areas where other preservation mechanisms such as cold storage are scarce. However, since the drying is often performed in a rural setting with poor hygienic conditions, the microbial quality of such products is uncertain. This study was conducted to evaluate the microbial quality of traditionally dried fish products from sites around the lakes of Tana, Ziway and Chamo, where fish drying is commonly practiced in Ethiopia. Eighteen composite samples were analyzed to determine the microbial load and water activity. High microbial load was recorded in most of the dried fish samples as indicated by total viable count (10 5 to 10 7 cfu/g); lactic acid bacteria (90 1 to 10 8 cfu/g); total coliforms (<10 to 10 4 cfu/g), and yeast and molds (10 3 to 10 5 cfu/g). The water activity value of all the dried fish samples was below 0.80, indicating the adequacy of the drying since the growth of pathogenic bacteria is not expected at a water activity below 0.86. However, a lack of hygiene during processing and handling was generally noticed. Hygienic processing and process standardization are required to improve the microbial quality of the dried fish.

Proteases are one of the predominant groups of industrial enzymes and it represents for about 65% of the total global enzyme market. Proteases of microbial origin have great importance over plant sources because they minimize industrial production costs, increase characteristics of the desired products and widely used in biotechnological process. Among the protease enzymes, aspartic proteases are the most important groups of proteolytic enzymes which are mainly produced by plants, animals and many microorganisms to degrade large polypeptides into peptides and amino acids. Microorganisms are also mainly preferred in the production of aspartic protease since they have most of the characteristics desired for biotechnological application rather than plant protease. Aspartic proteases produced from microbial sources are widely used in pharmaceutical, protein hydrolysis, detergent, cheese-making, photographic, baking, meat, leather, food and beverage industries. Although acid protease is vital to enhance the demands of many food and other industries, there are factors affecting the production of aspartic protease. Hence, aspartic protease production using microorganisms is highly affected by various carbon and nitrogen substrates, divalent metal ions, pH, incubation temperature, time, agitation speeds, age of inoculum and density. This review highlights on the production and applications of microbial aspartic proteases.

Drying is one of the old aged food preservation techniques that can be done efficiently in a cost-effective way. Rural fish producing areas in Ethiopia commonly use drying technique when the need for preservation is necessitated. Despite the relevance of the information, nutrient composition of dried fish products found in Ethiopia are not well recorded. This study was designed to evaluate the proximate composition and some mineral content of traditionally dried fish from sites located around the lakes of Tana, Ziway and Chamo in Ethiopia. A total of eighteen composite samples were analyzed for proximate composition and mineral content determination. The dried fish products had high crude protein (52.21 to 70.88)%, crude fat (2.89 to 8.60)% and minerals such as Calcium (36.44 to 9078.44 mg/100g), Potassium (636.61 to 3073 mg/100g), Phosphorous (570 to 5330mg/100g) and Sodium (78.92 to 7433.26). Because of difference in water content of the final dried product, variations were observed on the major nutrient compositions. Dried fish products generally proved to be important source of protein, energy and minerals. Besides the composition, dried fish products can be stored for extended time, thus increase accessibility of nutritious food. However, improvement of the drying technique, including hygienic processing is necessary.