ALADE, MAZEEDAT BOLUWATIFE and Covenant University, Theses (2021) MYCOFLORA, AFLATOXIN ASSESSMENT AND SHELF-LIFE STUDY OF Cyperus esculentus (TIGERNUT) AND TIGERNUT MILK USING Cymbopogon citratus. Masters thesis, COVENANT UNIVERSITY.
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Abstract
Aflatoxins produced by Aspergillus flavus and Aspergillus parasiticus, are secondary metabolites that pose a major threat to global food security. This could result in detrimental impacts on human and animal health. In this study, the presence of aflatoxigenic fungi and aflatoxins in Cyperus esculentus L. (tigernut) seeds and tigernut milk were assessed. Also, the shelf extension using Cymbopogon citratus (lemongrass) was determined. Samples were obtained from three major dealers in Ota, Ogun State using the snowball sampling technique. The seeds were cleaned and processed into tigernut milk, thereafter stored for further studies. The organisms were identified using morphological and molecular methods using the internal transcribed spaces ITS 1 and ITS 4. Qualitative and quantitative assessments of the toxigenic potential of the fungi were carried out using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) methods respectively. For the shelf-life study of tigernut milk, three different formulations were used (10ml, 15ml and 20 ml of lemon grass extract). Data obtained from this study were analyzed using descriptive statistics in form of mean and standard deviation. Total fungal count in tigernut and tigernut milk ranged from 1.47 × 103cfu/g - 6.94 ×105 cfu/ml. The predominant fungi in both samples were Aspergillus flavus (OK172340), Aspergillus orzyae (OK172339) and Aspergillus brasiliensis (OK17234). The aflatoxin levels detected ranged between 1.4 - 2.03ppb in tigernut samples while the tigernut milk samples were free of aflatoxin. Total fungal counts of the fortified tigernut milk ranged between 9.9×105 -1.28×106 cfu/ml. The fungal isolates identified over the 14 days shelf-life storage were Aspergillus spp., Penicillium spp. and Rhizopus spp. for each day. From the results obtained from the test panel, there was a general acceptance of the sensory quality; LA104 had higher general acceptance while LA267 had the least acceptance. The shelf-life was extended for 14 days without loss in the organoleptic properties of the tigernut milk. In conclusion, the tigernut and tigernut milk analyzed had aflatoxin content below the acceptable limit 4ppb with respect to National Agency Food and Drug Administration and Control (NAFDAC) guidelines. In addition, lemongrass improved the shelf life of tigernut milk over a period of 14 days under refrigerated condition.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Aflatoxins, Cympbogon citratus, HPLC, Tigernut, TLC |
| Subjects: | Q Science > Q Science (General) Q Science > QH Natural history > QH301 Biology |
| Divisions: | Faculty of Medicine, Health and Life Sciences > School of Biological Sciences |
| Depositing User: | Mrs Hannah Akinwumi |
| Date Deposited: | 22 Feb 2022 10:13 |
| Last Modified: | 22 Feb 2022 10:13 |
| URI: | http://eprints.covenantuniversity.edu.ng/id/eprint/15649 |
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