ONION IS ASSOCIATED WITH MICRO-ORGANISMS WHICH ARE CAPABLE OF CAUSING SPOILAGE

Onion is associated with micro-organisms which are capable of causing spoilage. Onions with rots were examined microscopically. A solution of it was made and the serial dilution of 1:10-1ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ�ÂÂ� to 1:1-5  were made from 10ml of the onions sample. From the dilution, 1ml of each diluent was plated on nutrient and saboor and  dextrose  agree to permit the grouth of the common bacterial and fungi, from the roffen onions. Duplicate plates were performed for each dilution. The plates was sivirled of gently to ensure even distribution of diluent and was incubated in inverted position  of 370 c for 24 hours. After 24 hours, the colorues  were counted, with vales yielding 30 to300 (to avoid TFTR and TNTC), the viable count per ml was defermined by multiplying the average number of colories of the duplicate plates by the corresponding factor (MPN table). Gram staining was carried out on the colories and examined microscopically. Representative colories were seperately sus-cultored on nutrient agar slopes for confirmatory characterization of the organism present Biochemical test for identification was also carried out. The result showed a mixed flora of bacterial and fungi including moulds as the organism responsible for spoilage of onions. The fungi isolated were  Mucor spp rhizopus spp, Aspergilus spp and saccharomycis spp. The bacteria isolated from the sample were staphylococcus aureus, streptococcus pyogenes and Bacillus spp.

Table 2: Composition of Raw onion Components                        --------------12

Table 2: total plate counts                                                              ---------------25

Table 3: Isolate from onions Sample                                            ---------------26

Table 4: Identification of  Bacterial isolates From onoins sample   -------------28

Table 5: Biochemical test for identification of bacterial isolates      ------------29                                                              

Title page              

  Certification                                                                                                 

Dedication                                                                                                     

Acknowledgement                                                                                          

  Abstract                                                                                                           

 List of tables                                                                                                  

Table of content       

1.0 Introduction                                                                 1.1 Background information                                                              

1.2 Aims of this research project

1.3 Statement of problems

1.4    Hypothesis

1.5   Significance of study

1.6   Limitation of this project 

2.0 literature review

2.1 Introductions

2.2 Species of onions  

2.3 Composition of raw onions

2.4 Dehydration of onions and uses of dehydrated onions

2.5 Basic principles involve in preventing microbial spoilage of onions

2.6 Spoilage of micro organisms

3.0 Materials and method

3.1 sample collection

3.2 materials used for the preparation of the medium

3.3 preparation of media

3.4 Preparation of sample

3.5 Microbial counts staining and microbiological work          

3.5.1 Biochemical test for identification          

3.5.2 Motility test           

3.5.3 Sugar fermentation test

4.0 Result  discussion

4.1 Result

4.2 Discussion

 5.0 conclusion and recommendation     

5.1 Conclusion

5.2   recommendation