MICROBIAL EXAMINATION OF VEGETABLE SOUP

ABSTRACT

This study was carried out on the microbial examination of vegetable soup. Five samples of vegetable (fluted pumpkin leaves) soup collected from different food vendors in (Campus 3) of the Institute of Management and Technology, Enugu were studied for bacteria spoilage. Different media were prepared and they include: MacConkey agar medium, nutrient agar medium, and blood agar medium.  After 24 hours of culturing on the media, observation of the plates incubated aerobically show heavy and profused growth of Bacillus cerus, moderate growth of Escherichia coli and Klebsiella aerogenes as well as scanty growth of Streptococcus feacalis and Staphylococcus aureus. The presence of E. Coli and Streptococcus feacalis indicated faecal contamination of the soup as these two organisms are known to be indicator organisms. They are usually associated with poor hygienic handling of foods, water, utensils and vegetables. Having known the spoilage organisms, the shelf life of vegetable (fluted pumpkin leaves) soup could be extended and improved by subjecting the soup to a more advanced preservation methods such as canning and drying.

CHAPTER ONE

INTRODUCTION

1.1   Background of the study

Vegetable soup is a generally warm soup that is made by combining ingredients such as meat, vegetable with stock, water, pepper, Onions, palm oil and others liquid. Vegetable soup are characterized by boiling solid and liquid ingredients in a pot until the flavours are extracted. Vegetable soups are eaten in a variety of ways as part of main meals and snacks.

Francis et al., (2001), point out that vegetable soup are consumed for their nutritional and medicinal benefits. The nutritional content of vegetable soup aeries considerably, though generally they contain little protein or fat and varying proportions of vitamins such as vitamin A, vitamin K and vitamin B6, provitamins, dietary minerals and carbohydrates.

In southern Nigeria because of their pleasant taste the leaves are generally considered as a great soup that has high concentration of icon and used by anemia patients to build up the blood cells (Ladeji et al., 1998).

Biochemical changes in food when perceived undesirable are called spoilage. Microorganisms can contribute to the degrading of the food quality that leads to spoilage. Because, foods are excellent sources of nutrient, microorganism grow rapidly and make what once was an attractive and appealing into a sour, foul smelling mass suitable only for the garbage can.

In other words, food can also serve as vehicles for disease transmission. The detection and control of pathogens in food spoilage micro-organisms are important parts of food microbiology.

During the entire sequence of food handling from the producer to the final consumer, microorganisms can affect food quality and human health (Joanne et al., 2008). The number and types of micro-organism present in food are influenced by the general environment from which the food items were originally obtained. The microbiological quality of the food in its raw state, sanitary condition under which the food are handled and processed as well as the adequacy of subsequent packaging, handling and storage are conditions in maintaining the flora at a low level (Jay, 2003). Fluted pumpkin leaves (vegetable) belongs to the family cucurbitaceous and grows in pods with seeds that are covered with a mucilaginous coating (Offonry and Achi, 1998). They are used as the major ingredients in preparation of a traditional soup called vegetable soup, which is popularly consumed in West Africa, particularly in Igbo tribe of Nigeria. The seeds can be roasted and eaten or ground as flour and used as a soup thickner. Various vegetable soups are favourites in Nigeria. In West Africa, plants and seeds of cucurbitaceous as well as soup, cakes and stews made with them are all called vegetable (Bankole et al., 2005).

1.2   Statement of the problem

One major problem that characterizes vegetable soup is that it deteriorates quickly, because the soup is rich in nutrient, it serves as a culture medium for bacterial growth (Bankole et al., 2005). Fluted pumpkin leaves “vegetable” soup is prone to fast spoilage than other soup especially during hot weather which results in food poisoning when consumed. As a result, majority of the populace prefer other soups than “vegetable” soup despite its cheap and easy method of preparation. Because of this, the aim of this work was to isolate and identify the spoilage bacterial of “vegetable” soup, which would help in the choice and type of preservative methods to be used in prevention of this spoilage.

Annous et al., (2005), explain that vegetable soup contains micro-organisms some of which are pathogenic and other are non-pathogenic. Moreover Wiswanathan et al., (2001). Highlight that the pathogenic micro-organisms in vegetable soup produce serious threat to the safety of the consumer and reduces quality as well as the acceptability of the products in vegetable soup. The above statements have prompted the need for a project work on bacteriological examination of vegetable soup.

1.3   Aim and objectives of the study

The main aim of this study is to carry out a microbial examination of vegetable soup.

The following are the specific objectives of the study:

1. To ascertain microbial safety of vegetable soup
2. To isolate micro-organisms associated with vegetable soup
3. To Identify the microbial types
4. To determine the microbial load of the sampled vegetable soup
5. To determine the microbial load, of each type

1.4   Significance of the study

The results of this project work would reveal the microbial safety of vegetable soup. The results would equally reveal if the microbial load of the sampled vegetable soups was high or low and if the microbial types involved were pathogenic or not. If the microbial load was high and the microbial types were pathogenic, then hygienic practices were not observed during the preparation of the vegetable soups and should be introduced. But if the microbial load was low, the microbial types were pathogenic, then hygienic practices were observed during the preparation of the vegetable soups and should be encouraged.

1.5   Limitation the study

This project was limited to microbial examination of vegetable soup.

Another problem encounter was poor Financial status on my part as a student which was a big problem during the project work.

Moreover, the cost of media and reagents was high, thus limiting the number of samples ran during the project analysis.

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