Microbial Analysis of Expired Canned Food Product (Liquid Canned Milk)
CHAPTER ONE
OBJECTIVE OF STUDY
To determine the presence of Micro organism in expired canned milk product and it’s effect in human system.
CHAPTER TWO
LITERATURE REVIEW
Chemical composition of canned food (CANNED MILK) milk is composed of milk fat, lactose (Milk Sugar) proteins, vitamins, minerals and water. The non-fat portion of milk is termed skimmed milk ever when not separated from the whole milk. Normal milk also contains the immunoglobulins, which protect the young from infections disease (Jennes and Patton, 1999).
TYPES OF DAIRY FOODS
In 2005, world milk production was estimated at 644 million tons, of which 541 million tons was cows’ milk. The leading producers of milk were the European union at 142 million tons, India at 88 million tons, the united state at 80 million tons (20.9 billion gallons), and Russia at 31 million tons in western Europe and 4.8 million tons in united state (Anonymous, 2007, Kutzemeier, 2006). The vast array of products made from milk worldwide leads to an equally impressive array of spoilage micro-organisms. A survey of dairy products consumption revealed that 6% of us consumers would eat more dairy products if they stayed fresher longer (lermpart, 2004). Products range from those that are readily spoiled by micro-organisms to those that are shelf table for many months, and the spoilage rate can be influenced by factors such as moisture content, PH, processing parameters, and temperature of storage.
CHAPTER THREE
MATERIALS AND METHODS
The materials used for this work include, petridishes, conical flask, test tubes, cotton wool, Aluminum foil, wire loop, slides, pipette, Bunsen burner, Autoclave etc.
COLLECTION OF SAMPLE
Five different brands of expired canned milk was purchased in owerri main market and transferred to the laboratory for analysis.
MEDIA USED:
The media used in this work include; nutrient agar, MacConkey agar, Eosine methylene blue agar, distilled water, all media were prepared following the manufacturer’s instructions.
STERILIZATION OF MATERIAL
The sterilization was done using the procedure stated by ogbulie et al; (2001), the glass wares were first washed with detergent and rinsed with tap water. It was allowed to dry and then oven dried at 16ooc for I hour before sterilization in autoclave at 121oc for 15 minutes.
ANALYSIS OF SAMPLE
Each sample was serially diluted using sterile distilled water as diluents and 1ml of 104 and sample was plated-in duplicate using the pour plate method on nutrient agar, macConkey agar and Eosine methylene blue agar media the plates were incubated at 37oC for the 24hrs. To estimate the total heterotrophic bacteria count of the expired canned milk samples. The colonies that develop on media plates were counted and used to determine the total bacterial count of expired canned milk sample (CFU/ml) the isolate colonies on the plates were subculture on fresh media plates to obtain pure cultures of the isolate, the pure cultures were then transferred into Eosine methylene blue agar for biochemical identification.
CHAPTER FOUR
ANALYSIS AND RESULT
ANALYSIS
The five samples (Peak, Nunu, Lunea, Loyal, three crown milk) Of expired canned milks from Owerri main market, Imo State were analyzed for microbial contamination which revealed the presence of staphyloccous aureus in peak milk, streptococci Spp. In Nunu milk staphylococcus aureus, in lunea milk and Escherichia coli in loyal, as, show in Table 1 below.
From table2 below, the result on macConkey agar revealed the presence of staphylococcus aureus in peak milk and loyal, streptococci in nunu and Esheriachia Coli in three crowns. Table 3, on Eosine methylene blue agar, this revealed the presence of staphylococcus aurens in peak milk, Lunea milk. In Nunu milk streptococci Spp. Was found while in Loyal and three crown milk Escheriachia Coli was identified. The number of isolate in each of the five (5) samples were as follow:
Peak Milk (8.4×10-5, 6.0×10-6, and 19.2×10-5).
Nunu Milk (3.0×10-6, 3.7×10-6, 3.7×10-6, 8.6×10-6).
Lunea Milk (1.0×10-6, 2.0×10-6, 1.5×10-6).
Loyal Milk (7.4×10-6, 3.0×10-6, 7.4×10-6, 9.4×10-6).
Three Crown (1.8×10-6, 9.0×10-6, 1.0×010-6).
CHAPTER FIVE
DISCUSSION AND CONCLUTION
A total of five different expired canned milks in owerri main market Imo state were analyzed for microbial contamination.
The results of the total heterotrophic bacterial and coliform count of expired canned milk using pour plate techniques reveales the presence of staphylococcus aureus, Escheriachia coli and streptococci Spp. This may be as a result of preparation, either through the hands of the people handling the product. Also this may be as a result of the use of wasterilized canns in cuppling the milk product. This presence of microorganism in the canned milk product can be as a result of contamination through the environment, due to micro organism are ubiquitous in the environment from which they contaminate the cow, equipment, water, and milkers hands since milking
machines exert about 38 cm (15in,) of vacuum on the teats during milking, and since air often leaks into the system, bacteria on the surfaces of the cow or in water retained from pre milking preparation can be drawn in to the milk. Also, when inflation clusters drop to the floor, they pickup microorganisms that can be drawn in the milk. Escheriachia coli and staphylococcus aureus were more dominant as a result of accidental Feacal released in the environment when milk is being manufacture.
This is agreement with the study carried out by marshall, 1976, chrisope and marshall, 1976 who isolates staphylococcus aureus, escheriachia coli, pseudomas and streptococci spp.
CONCLUSION
The conclusion drawn from this research work was that, the microbial content of expired canned milk product is a result of an indication of possible feacal contamination of the product by potentially pathogenic organisms and public health which causes a wide range of food borne-diseases some of the sources of microbial contaminants are from the food handlers, the container used for filling and the plant sanitation.
RECOMMENDATION
The food handlers should make use of protective clothes while working as well as observe aseptic techniques while working.
- Quality control test should be carried out on any product immediately after production before it is marketed, it possible the quality control test should be done at every stage of the production to help reduce the presence of feacal contaminants.
- There should be a provision for an agency that would enlighten the consumers to avoid consuming expired canned milk products as well as ensure that the production companies have an expiry data on each of their products.
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