PUBLIC HEALTH SIGNIFICANCE OF AFLATOXIN PRODUCING MOULD CONTAMINATION OF MAIZEAND MAIZE PRODUCTS FROM SELECTED MARKETS IN PARTS OF KADUNA STATE, NIGERIA
PUBLIC HEALTH SIGNIFICANCE OF AFLATOXIN PRODUCING MOULD CONTAMINATION OF MAIZEAND MAIZE PRODUCTS FROM SELECTED MARKETS IN PARTS OF KADUNA STATE, NIGERIA
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Date
2014-12
Authors
SULE, ENYISI ISAH
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Abstract
A study to determine the public health significance of mould contamination of maize and maize products in selected grain markets within Kaduna state was carried out from March 2010 - February 2011, using physical analysis, proximate composition analysis, mineral determination using atomic absorption spectrophotometer and mycological procedures.Aflatoxin production ability of isolated moulds was evaluated using the thin layerchromatography (TLC)technique and Enzyme Linked ImmunosorbentAssay (ELISA). The mean temperature, relative humidity and monthly rainfall from all the markets were 30oC, 48% and 3.2mm respectively. In terms of quality, the percentage wholesomeness to broken or damaged grains was found to be high and significant differences were found to exist between percentage whole, broken and damaged grains (P< 0.05).Proximate composition of maize and maize products at four weeks post storage in a low density polythene bags were in the range of 11.6- 20 .0% (moisture), 1.10 – 2.95% (Ash), 4.50 – 9.87% (protein), 2.17-4.43 (fat), 2.10- 26.70% (fibre) and 44.60- 69.60% (carbohydrate). Statistical analysis using ANOVA showed significant differences between the mean values of the nutrient content of all the products except for moisture. Mineral elements of the maize and maize products namely: phosphorus, magnesium and potassium were found to be higher than other elements: zinc, calcium,copper, sodium, manganese and iron. The bulk of these minerals were concentrated in the maize bran. The mean levels of fungal density ranged from log10 1.00 – 4.9 for old maize; log10 1.17 – 2.6 for new maize; log10 1.95 -4.90 for maize flour and log10 1.26 -5.34 for maize bran .The effect of seasonal variation of mould count was determined and result revealed a significant high total count (P< 0.05) of mould in all the products in wet season. A total of five fungal genera namely:
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Aspergillus,Penicillium, Rhizopus,,Fusarium and Botrytis were isolatedAspergillus was the most predominant following the orders: A. niger>A. tamari>A. flavus. Theaflatoxin production ability of theAspergillus species indicated that, onlyAspergillusflavusshowed the ability to produce aflatoxin. Higher aflatoxin contamination (100%) and (82.70%) of the maize and maize products had total aflatoxin levels above 4ppb and 20ppb recommended by Standard Organization of Nigeria (SON) and Food and Drug Administration of United States as tolerance levels. Significant differences existed between the mean aflatoxin contaminations of old maize, fresh maize, maize flour and maize bran.Emphasis on proper harvesting, drying, handling, transportation, storage and education of the populace especially those dealing with these foods should be taken into consideration by relevant authorities. In conclusion, the high level of aflatoxin in maize and maize products may highlight the problem associated with the consumption of these products with the toxin that could lead to adverse health effects such as liver, cervical, breast or oesophageal cancer.
Description
A DISSERTATION SUBMITTED TOTHE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD
OF A DOCTOR OF PHILOSOPHY IN MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY,FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY, ZARIA NIGERIA
Keywords
PUBLIC HEALTH,, SIGNIFICANCE,, AFLATOXIN,, PRODUCING,, MOULD,, CONTAMINATION,, MAIZE,, MAIZE PRODUCTS,, SELECTED MARKETS,, PARTS,, KADUNA STATE,, NIGERIA