Bacteriological Quality Of Frozen Chicken Sold In Gwagwalada Market

Project and Seminar Material for Microbiology

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 × 102cfu/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.

1.2 Aims And Objectives

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

To isolate the various microbial isolates associated with frozen chicken purchased from different sellers in Gwagwalada market.
To characterize and identify these micro-organisms.
To speculate on the significance of these isolates.
To compare the level of contamination of the samples (frozen chicken) collected from different parts of the market.

Chapter Five

Discussion, Conclusion And Recommendation

5.1 Discussion

According to international microbiological standards (Amon, 1974 and Refai, 1979), recommended limits of bacterial contaminants for foods are in the range of 101 – 102cfu/g of food for coliform organisms and less than 105cfu/g of food for total bacteria plate counts. The present study as shown in Table 1, however revealed that all the frozen chicken under the different designated retailers/sellers were within the acceptable range for total bacteria count i.e. seller 1 gave a range of 0.7× 102 –1.2 × 102cfu/g, seller 2 gave a range of 4.0 × 102cfu/g – 6.6× 102cfu/g , seller 3 gave a range of 3.0 × 102cfu/g – 10.3 × 102cfu/g, seller 4 gave a range of 3.6× 102 – 9.3 × 102cfu/g and seller 5 gave a range of 4.5 × 102 – 8.5 × 102cfu/g. For the coliform count only the frozen chicken from seller 1 was within the acceptable range of 0.1 × 102 – 0.5 × 102cfu/g while the frozen chicken from the other sellers were above the acceptable range i.e seller 2 gave a range of 0.9 × 102 – 2.8 × 102cfu/g, seller 3 gave a range of 0.5 × 102 – 2.4 × 102cfu/g, seller 4 gave a range of 1.1 × 102 – 3.4 × 102cfu/g and seller 5 gave a range of 1.1 × 102 – 3.2 × 102cfu/g. This is in agreement with the findings of other workers (Bryan et al., 1981; Van steenbergeret al., 1983; Bryan et al., 1986) concerning frozen chicken stored under different conditions giving a range of 1.4 × 102 – 3.1× 102 for total bacteria count and 1.2 × 101 – 3.2 ×101 for total coliform count of the isolates from chicken freezer depots, 1.5× 103 – 6 ×106 total bacteria count and 1.2 ×102 – 8.5 ×102 for total coliform count of the isolates from open markets and 1.1×101 – 1.5 ×101 for total bacteria count and 1.2 ×102 – 1.5 ×102 for total coliform count of the isolates from cold rooms. However, the result revealed a high microbial of pathogenic bacteria obtained from samples kept in the open market. This might have been as a result of contaminations resulting from poor hygiene on the part of the sellers, from various contaminating insects and during evisceration of the chicken during processing.

A total of 8 bacteria species were isolated from the examined frozen chicken samples i.eStaphylococcusaureus (20), Staphylococcusepidermidis (8), Bacilluscereus (5), Escherichiacoli (2), Proteusvulgaris(4), Klebsiellapneumonia (4) and Pseudomonasaeruginosa (5). The presence of Staphylococcusaureus and Staphylococcusepidermidis was high in the frozen chicken because they are frequently found on the human skin since they form part of the skin flora and they are easily transferred to the frozen chicken from the seller especially in the absence of hand gloves. They can also be spread through contaminated surfaces. Meanwhile the enteric organisms which are Escherichia coli, Proteus vulgaris, Klebsiella pneumonia and Pseudomonas aeruginosa are present in the frozen chicken as a result of faecal contamination and the presence of Bacillus cereus is as a result of soil contamination because they are soil dwelling. The presence of these organisms are also sources of diarrhea and or gastro intestinal disturbance to both adult and children when consumed and may lead to food intoxication.

Statistically, it was seen that there was more likelihood of contamination of the frozen chicken from the sellers (p<0.05) than from the place of storage (refrigeration) of the chicken (p>0.05).

5.2 Conclusion And Recommendation

From the studies, low microbial count was however experienced from seller 1as a result of proper hygiene and the use of hand gloves which reduces the risk of contamination and also proper refrigeration of the frozen chicken in cold room which maintained a very low temperature making it difficult for majority of the microorganisms to survive. The slighty high microbial count as observed in other sellers might have been due to poor hygiene on the part of the workers and might have been as a result of the constant exposure of the chicken parts to the open environment. Other factors can be poor sanitary conditions, open tables, perching by flies and other organisms, spores of bacteria from the open environment, knives and tables on which these chicken parts have been placed.
I suggest that frozen chicken should not be sold in open markets but rather in neat and organized shops in order to reduce the risk of contamination as a result of exposure to spores or poor hygiene. Materials such as tables, knives, chopping boards used in the processing of the chicken should be thoroughly cleaned with disinfectants and kept under aseptic conditions. Handlers should also wear hand gloves when processing and wrappers should be sterile before being used to package the chickens. Frozen chicken should be well packaged and sold whole rather than selling in bits. This is because microorganisms can be introduced through contaminated surfaces such as tables and chopping boards, and knives in the process of chopping/cutting/slicing it. Proper storage of frozen chicken in cold rooms and freezers is very important for adequate preservation and also to prevent contamination from the presence of microorganisms. Government can also set up agencies that will be responsible in making sure that handlers abide by the proper methods of processing frozen chicken in order to protect the public from food-borne diseases. If these basic practices are carried out, the public is assured of not only sumptuous chicken meals but also great improvement in general health and wellness.