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Onion Is Associated With Micro-organisms Which Are Capable Of Causing Spoilage
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The deterioration of raw onions may result
from physical factors; actions of their own enzymes, microbial or
combination of these factors. Mechanical damage resulting from action of
animals, birds or insects or from brushing, wounding, bursting,
cutting, freezing, desiccation or other mishandling may predispose
towards increased enzymatic action or entrance, and growth of
microorganisms. Also previous damage by plant pathogens may make the
part of the crop used as food unfit for consumption or may open the way
for growth of saprophytes and spoilage by them. Contact with spoilage
onions may bring about transfer of organisms causing spoilage and
increasing the wastage. Improper environment condition during harvest,
transit, storage and marketing may favor spoilage.
Genera of bacteria
usually present in onion include pseudomonas spp, Bacillus spp,
chromobacterium, Enterobacterium, flavobacterium, lactobacillus
serratia, staphylococcusspp, streptococcus spp and others and perhaps
genera containing plant pathogens, such as Erwinia and xanthomomes.
Grouwth of some micro-organisms may take place between harvesting and
processing or consumption of the vegetable. Adequate control of
temperature and humidity will reduce such growth (frazier and westhoff,
1978).
1.2 AIMS OF THIS RESEARCH PROJECT
The aims of this research project are:
1
to isolate, identify and characterize the different micro-organaniszs
that are responsible for the spoilage of onions.
2 To categorize the pathogenic micro-organisms associated with the spoilage of onions.
1.3 STATEMENT OF PROBLEMS
The
society is a place where a vegetable is been consumed everyday. This
project research goes a long way in identifying problems which is
encountered when spoilage occurs in onions; onion bulb that is
contaminated when consumed causes severe stomach ache (presence of
enterobacteriacea) because of the pathogenic micro-organisms present in
if and this inturn is hazardous to ones health. The pathogenic
micro-organisms present in the spoilage of onoins are deterimental to
humans e.g pseudomonas spp., staphylococcus spp, Erwinia etc.
Onions
been a member of the vegetable group is used widely in seasoning,
flavouring and sometimes cured and stored as spicing agent. The proper
storage of onions makes it available for use all year round and the
effect of spoilagemicro-organisms afecting it has an adverse efect on
the society at large because if makes onions not readily available to
the society; that is why studies is been carried out in this project
research to minimize and or stop spoilage of onions.
1.4 HYPOTHESIS
HO-A mixed flora of bacteria and fungi is found in spoilt onions.
Hi-bacteria
and fungi found in onion result in the onions own enzymatic actions
causing physical, microbial or combination of these factors leading to
entrance and or growth of micro-organisms.
1.5 SIGNIFCANCE OF STUDY
The
justification of this project research is to ascertain the different
micro-organism responsible for the spoilage of onions. In this process
bacteria and fungi were isolated identified and characterized because
they are the microorganisms associated with the spoilage of onions.
The
deterioration of raw onions can also result from physical factors,
actions of their own enzymes, microbial action or combination of these
factors. In physical factors; the storage patter can affect the raw
onions that is if it is stored in bulk or may be placed in palletized
bins and this does not make ventilation of the onions easily, so
improved bins design may be of great help. In action of their own
enzymes; if the raw onions is crushed during packaging, handling, this
may inturn allow the penetration of micro – organisms which will now
alter the enzymatic action of the raw onions and may lead to spoilage of
the onions flesh which is meant for food and if consumed could be
hazardous to health.
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ABSRACT - [ Total Page(s): 1 ]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 1:10-1¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬ 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 p ... Continue reading---
