ABSTRACT

Twenty samples of frozen chicken from five different sellers were analyzed to determine their bacteriological load; the samples were collected from Gwagwalada market. All the frozen chicken samples from the five sellers examined were contaminated with some bacterial species namely, Bacillus cereus, Escherichia coli, Staphyloccus aureus, Staphylococcus epidermidis, Proteus vulgaris, Klebsiella pneumonia, Pseudomonas aeruginosa. The total bacteria counts for all the chicken examined from the different sellers was in the range of 0.7 × 102

cfu/ml to 8.5 × 102 cfu/ml and the coliform counts obtained for all the chicken samples ranged from 0.1 × 102 cfu/ml to 3.2 × 102 cfu/ml. These finding suggest that most of the frozen chicken parts stored in the open market may constitute sources of bacterial food poisoning consequently public health hazard.

CHAPTER ONE

1.0                                 INTRODUCTION

The first consumer right is to have a product of good quality and not constituting any health hazard. Poultry meat products are highly desirable, palatable, digestible and nutritious for all ages. Poultry meat is comprised of about 20–23% protein, other are water and fat, phosphorus, iron and vitamins. Comminuted products, such as frankfurters, bologna and sausages typically contain about 17–20% protein, 0–20% fat, and 60–80% water (Smith, 2001).Quality products are those that meet some need or expectation of consumers and are safe and wholesome as well. (Sahooet al., 1996).The microbiological safety and quality of poultry meat are equally important to producers, retailers and consumers. Two quite different groups of microorganisms are relevant: on the one hand certain foodborne pathogens, and, on the other, organisms that are generally harmless to human health, but, being psychrotrophic, are able to multiply on the product during chill storage. Spoilage results mainly from off- odour development, and product shelf-life is determined both by the number of spoilage organisms present initially and the temperature history of the product at all stages of production and subsequent storage and handling (Pooni and Mead, 1984). For chill- stored poultry, Viehweget al. (1989) demonstrated that virtually all the odorous substances found at spoilage could be attributed to microbial growth and metabolism. Contamination of poultry meat with foodborne pathogens remains an important public health issue, because it can lead to illness if there are malpractices in handling, cooking or post-cooking storage of the product.

Fresh (uncooked) foods such as chicken carries natural microflora that may contain organisms potentially harmful to humans. The microbial flora of table poultry is largely confined to the skin surface or visceral cavity. Isolates from poultry and poultry products could include members of the following general Enterobacter, Alcaligenes, Escherichia,Bacillus, Flavobacterium, Micrococcus, Proteus,Pseudomonas, Staphylococcus, Corynebacteriumand Salmonella. (Frazier and Westhoff,1988).

Contamination of the skin and lining of the body cavity occurs during washing, plucking and evisceration. Bacterial numbers vary considerably on the surface of chickens. This variation however is greater between birds than is between different areas of the same birds. The type of organisms isolated depends upon where the samples were taken and upon the stage of processing (Frazier and Westhoff, 1988). Fresh poultry products like meat are known to undergo deterioration due to microbial action, chemical and physical changes. In normal handling and storage of poultry meat, this deterioration changes are attributed to micro biological contamination and activity.

Poultry and poultry products are frequently contaminated with several types of microorganisms. This problem is even more severe under temperature-abused conditions as well as improper or inefficient refrigeration commonly observed in retail chicken sold in open markets. Poultry can be kept in good condition for months if freezing is prompt and rapid and the storage temperature is low enough. Poultry should freeze fast enough to retain most of the natural bloom or external appearance of a freshly dressed fowl. The storage temperature should be below 17.8oC and the relative humidity above 95 percent to reduce surface drying. Most poultry is sharp-frozen at about 29oC or less in circulating air or on a moving belt in a freezing tunnel. Other spoilage micro-organisms are introduced into the poultry products by the workmen during cutting and evisceration, through water, and air in the dressing, cooling and cutting room environment (Allenet al., 2000). However, various methods are used in the preservation of these poultry products in order to reduce the incidence of these organisms. These include asepsis, use of heat, use of low temperature, chilling, freezing, preservatives such as acetic, adipic, succinic etc. at pH 2.5 and use irradiation (Frazier and Westhoff, 1988). Despite these methods of preservation, contamination of poultry products remains the order of the day before it gets to the final consumer.

1.1   AIMS AND OBJECTIVES

Various bacteria are associated with poultry products; this project is aimed at achieving the following objectives:

i.       To isolate the various microbial isolates associated with frozen chicken purchased from different sellers in Gwagwalada market.

ii.       To characterize and identify these micro-organisms.

iii.      To speculate on the significance of these isolates.

iv.      To compare the level of contamination of the samples (frozen chicken) collected from different parts of the market.