The study was conducted to determine the effect of location on the microbial assay and proximate composition to raw meat samples in Ogo oluwa local government area of Oyo State. A total of four raw meat samples were purchased randomly from meat sellers in the local government area. The raw meat samples were wrapped in a sterilized container to prevent contamination and then transported to the laboratory for microbial analysis and proximate composition immediately after collection in the morning, afternoon and evening.
Two different organisms were isolated from the meat samples collected in the local government area with Clostridium sp. and Staphylococcus aureus. The proximate composition of the raw meat samples analyzed revealed that there was significant (p<0.05) difference among the meat samples collected from various meat sellers in the local government. According to the results, it can be deduced that meat samples collected in the morning possessed a higher and more favorable proximate composition and nutritive value compared to those collected in the afternoon or evening. Although, the microbial loads observed in this study were lower than those reported by previous researcher. None the less, effort should be geared towards preventing further increase of microbes on suya in the study area by ensuring perfect hygiene and sanitary condition.
Food habits of society have substantially changed due to rapid urbanization and hurried way of living, resulting in increased demand for ready to cook and ready to eat meat product. Consumers have become conscious in the selection of quality, concerned about value for money, freshness and health aspects of meat food products (Selvan et al., 2007). Meat is a nutritious, protein-rich food which is highly perishable and has a short shelf-life unless preservation methods are used. Shelf life and maintenance of the meat quality are influenced by a number of interrelated factors including holding temperature, which can result in detrimental changes in the quality attributes of meat (Olaoye and Onilude, 2010).
In developing countries, especially Nigeria meat is widely accepted and consumed as a source of protein; it is either eaten cooked or processed into other forms to avoid associated spoilage (Olaoye et al., 2010; Olaoye and Onilude, 2010). Meat is not highly susceptible to spoilage, but also frequently implicated to the spread of food-borne illness, various biochemical changes and microorganisms are associated with meat, during the process of slaughter, processing and preservation (Olaoye and Onilude, 2010). Chemically meat is composed for four major components including water, protein, lipid carbohydrate and many other minor components such as vitamins, enzymes, pigments and flavor compounds (Lamber et al., 1991). As cited in Olaoye (2011), the relative proportions of all these constituents give meat its particular structure texture, flavor, colour and nutritive value. However, because of its unique biological and chemical nature, meat undergoes progress deterioration from the time of slaughter unit consumption.
Approximately 69% of gram negative bacteria are known to cause bacterial food borne disease (Okonko et al., 2010). Several researchers have reported that the meats sample were contaminated with high level of Klebsiclla pneumonia, Enterobacter sp, Pseudomonas aeruginosa, Escherichia coli, Salmonella sp., Serratia marcescens and Proteus vulgaris, Staphylococcus aureus and Bacillus sp. (Okonko et al., 2010, Collins and Thato 2011).
On the other hand, food-borne pathogens are able to disseminate from contaminated meat to the surfaces (Gorman et al., 2002) and can spread infections in the community. Meat is considered to be spoilt when it is unfit for human consumption. Meat is subjected to changes by its own enzyme, by microbial action and its fat may be oxidized chemically by microorganisms that are grown on the meat causing visual, textural and organoleptic change when they release metabolites (Jackson and Megowan, 2001).
As cited in Abdel (2010), meat and meat products are highly perishable which spoil easily, soon become unfit for human consumption and possibly dangerous to health through microbial growth, chemical changes and breakdown by endogenous enzymes. Meat is high perishable, because it is high in protein and moisture and semi-neutral in pH which makes it an ideal medium for bacterial growth (Warriss, 2000). Chemical composition of meat favors microbial growth to unacceptable levels contributing significantly to meat deterioration or spoilage. When large number of microorganisms are present in raw meat, there will be changes such that it becomes unappealing and unsuitable for human consumption (Fung, 2010; Gram et al., 2002). The initial microbial load of meat depends on the physiological status of the animal at slaughter, the spread of contamination into slaughter houses and during processing, while temperature and other conditions of storage during distribution can also influence the rate of spoilage (Nychas et al., 2008).
The different microbial groups that will potentially contribute to meat spoilage depend on:
- The storage conditions applied and
- Their competition.
The development of such microbial association is reported to significantly affect the type of spoilage. There are two possible situations in the case;
- One which facultative anaerobic or anaerobic Gram-positive micro-biota determines the change in the ecosystem (e.g. meat stored under low oxygen availability with or without the presence of anti-microbial gases) and
- Another where aerobic or facultative anaerobic Gram-negative bacteria (meat stored aerobically and/or under high oxygen tension) dominate the microbial succession (Agapi et al., 2010).
Meat from open abattoirs in several market contain higher microbial load because of the large amount of exposed surface area, more readily available water, nutrient and greater oxygen penetration. In spite of the obvious unhygienic environment that animal are slaughtered, there is increase demand in the consumption of meat due to the improvement in the standard of living, increased urbanization, higher deposable income, and the human desire for a greater variety in their diets (Sofos, 2008). The production of hygienic meat is of utmost importance so as to safeguard the health of the consumers. Therefore, this research work aims to investigate the microbial quality of raw meat available in common abattoirs in the study area.
Because meat is one of the richest source of protein which is needed for repair of worn out tissues and body building in human, determination of the microbial assay and proximate composition of raw meat ready for consumption and also to know the best time to buy meat from meat sellers in the study area (Ogo Oluwa Local Government Area of Oyo State) becomes very necessary in order to devise methods to reduce or eliminate the microorganisms associated with raw meats.
1.2.1 General Objective
To determine the microbial assay and proximate composition of raw meat ready for consumption in Ogo-Oluwa Local Government of Oyo State.
1.2.2 Specific Objectives
- To assess the effect of microbial load on quality of raw meat in Ogo-Oluwa Local Government of Oyo State.
- To determine the proximate composition of raw meat in Ogo-Oluwa Local Government of Oyo State.
iii. To evaluate the microbial assay of raw meat in Ogo-Oluwa Local Government of Oyo State.