MICROORGANISM ASSOCIATED WITH SPOILAGE OF TOMATOES (CANNED TOMATOES)
TABLE OF CONTENT
2.0 Literature review
2.1 History of canned tomato
2.2 Types of canned Tomatoes
2.3 Nutrition facts of canned tomatoes
2.4 Common additions of canned tomato
2.5 causes of canned tomatoes spoilage
2.6 Control/preservation of canned tomato
3.0 Materials and Methods
3.1 Place of experimental work
3.2 materials used
3.2.1 Reagent used
3.3 Collection of sample
3.4 Medium preparation
3..4.1 Preparation of nutrient agar
3.4.2 Preparation of potato dextrose agar
3.5 Sample preparation
3.6 Microbiological Analysis of the Sample
3.6.1 Determination of analysis load (bacterial and Fungi Load)
3.7 Preparation of pure cultures pf Isolate (bacteria and fungi)
3.7 Identification of bacteria isolates
3.7.2 Colonial or cultural characteristics
3.8 Gram Staining
3.8.1 Indole test
3.8.2 Motility Test using stab cultures techniques
3.8.3 Methyl Red (Mr ) Test
3.8.4 Volies –proskader (VIPs) test
3.8.5 Identification of fungi
3.9 Microscopic Examination
3.10 biochemical Reactions
4.0 Microbial Load or bacteria Associated with canned Tomato spoilage
The micro-organism, associated with spoilage of tomatoes shows that tomato contain large amount of water which makes them more susceptible to spoilage by the action of various micro-organism. Out of the (3) three sources of samples used in the assessment revealed that Bacillus species identified in the spoiled sample are the major causes of canned spoilage while the fungi isolates are peniucillum species etc which revealed by the assessment are also the cause of tomato spoilage. In this assessment carried out, it was found out that bacterial species were the source of spoilage rather than bacteria because it dominated all the plates.
Canned tomatoes are tomatoes usually peeled that are sealed into a canned after having been processed by heat.
This product are considered important world wide (Robinso, et al, 1994). In Nigeria tomato paste is the most important tomato product because of its wide spread use for preparation of various food/menus. It contain on the average about 6.4% total solids, of which 3.5% is invert sugar, 0.5% citric acid,0.6% ash, 0.9% protein, 0.53% crude fibre and about 0.05% fat. When spoil as a result of the life processes of bacteria, yeast and molds, the sugars are rapidly used up being changes into acetic acid, lactic acid, alcohol and carbon dioxide, the amount of these substances depending on the types of organism which are most active in the particular sample in question.
Until recent years, nearly all the tomato paste consumed in Nigeria was important from European countries with Italy being the leading country. However, today, limited brands are produced locally. Although both the imported and the local brands are available on the market, consumers prefer the former in spite of its relatively higher cost.
In general, adequate heat processing is given to tomato paste to achieve commercial sterility (speck, 1984), but subsequent abusive post-process handling/storage may lead to undesirable microbiological changes (Anon, 1980). It is public knowledge that can of tomato paste often show external evidence of spoilage under tropical retail conditions. In addition, and interestingly, these d effective products are sold (especially to the less informed) at the same cost as the normal (non-defective- product.
The structural systematic approach for the control of food safety “Hazard Analytsis and critical control point-HACCP” identifies, evaluated and controls hazards that are significant for food safety. The control parameters include various factors such as time of harvesting, temperature and moisture during storage, selection of agricultural products prior to processing, decontamination conditions, addition of chemicals at final product storage ((Sango, 1995).