Influence of Storage Conditions on Shelf-Life of Dried Beef Product (Kilishi)
Abstract: The effects of storage methods on the shelf-life of dried beef product (Kilishi) were studied under ambient conditions for a period of forty-two days to compare traditional production and packaging system with a potassium sorbate (anti-fungal agent) treatment and modern packaging system. Changes in proximate composition and microbial counts for the control and treated samples were significant. Moisture and water activity results indicated that the experimental kilishi was sufficiently dried to minimize microbial growth. Fatoxidation levels measured by percent free fatty acid (FFA) on extracted fats were unacceptably high and maybe a reflection of the quality of peanut cake paste added as a condiment in dried beef processing. A decrease in mineral nutrient of kilishi was also observed.. Results suggest that treatment of kilishi with 10% (w/v) potassium sorbate led to low and acceptable level of mould growth during the storage period, indicating that kilishi is not susceptible to excessive mould contamination. Aflatoxin levels far exceeded recommended safe limits and may be due to the peanut cake paste used as a condiment.
Key words: Storage conditions % Shelf-life % Kilishi % Chemical compositions % Microbiological counts
INTRODUCTION
The main method of meat preservation transferred by the medieval Arabs in the 12th century was that of sundrying. A variety of traditional products have been developed that rely on the interaction of preservation techniques involving a restriction of water activity by drying, use of salts and sugar to further control water activity and to act as selective inhibitors of microbial and enzymatic action and use of spices to further limit microbial growth and to impact characteristic flavour.
The curing of meat is a process that depends on the inhibition of microbial growth by the use of sodium chloride and control of water activity, with optional additional use of nitrite salts to stabilize meat colour; and smoking to give further microbial control and a desirable cured meat flavour. As a result, many traditional processes have been developed to give products of distinctive character. Although modern methods of meat preservation such as refrigeration and freezing method might be preferred by consumers, refrigeration equipment are expensive to install and difficult to maintain in developing countries.
There are many methods used to prepare dried meat. These include exposure of strips of lean meat to the sun, as in the manufacture of Pemmica by North America Indians, or a combination of salting followed by air drying, as in the preparation of Charqui in South America and Biltong in South Africa [3]. The dried beef product Kilishi is a delicacy in Africa equivalent to Pemmica and Charqui.
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