Muhammad, Abrar (2009) Occurrence of Aflatoxin in Groundnut and Spices During Storage. PhD thesis, University of Agriculture, Faisalabad .
Aflatoxins are secondary metabolites produced by the species of Aspergillus, specifically Aspergillus flavus and Aspergillus parasiticus. The aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds implicating as causative agents in human hepatic and extra hepatic carcinogenesis. The present project was divided into three parts. In the first part (Study I), the chemical changes in spices and groundnuts were studied under different packaging materials and storage conditions. There was no aflatoxin was detected in all groundnut varieties and spices. Cumin, red chillies and black pepper samples stored in jute bags showed maximum moisture contents as compared to high density polyethylene (HDPE) bags. Moisture content in cumin samples also increased significantly at 85% RH. Moisture content in all the samples increased as a result of storage and humidity. The storage, humidity and packaging materials showed non-significant effect on ash, protein, fat, fiber, nitrogen free extract (NFE) and total phenolics in groundnut varieties. The total fungal count, Aspergillus count and total aflatoxin in all spices was significantly (p< 0.01) affected due to packaging material, relative humidity, storage intervals and interactions of these variables. However, low level of total aflatoxin was detected in spices as compared to groundnuts. The chemical constituents like crude protein, crude protein, crude fiber, ash and NFE differed significantly among different groundnut varieties. However, storage intervals, packaging materials and interactions between these variables non-significantly affected the proximate composition of groundnuts varieties except moisture content which was increased during storage. In study II, after 120 days of storage the contaminated samples were packed in HDPE and irradiated by gamma radiation @ 2, 4 and 6 kGy and stored at room temperature and relative humidity in paper carton box along with control (0 kGy) for 90 days. The gamma radiation showed significant effect on total fungal count and aspergillus count as compared to control. Irradiation and storage showed non-significant effect on proximate composition and total phenolics of spices. The third (Study III) comprised the use of groundnut oil in cookies as to replace normal shortening and its effect on quality attributes of cookies during two month of storage period. The physico-chemical analyses and fatty acid profile of groundnut oil was performed. The results regarding fatty acids profile of groundnut oil indicated that GNO contain low level of saturated fatty acids; myristic acid (0.04%), palmitic acid (9.85), stearic acid (2.53), arachidic acid (1.21), behenic acid (2.52) and lignoceric acid (2.42%) while higher level of un-saturated fatty acids oleic acid (55.36%), linoleic acid (26.96%) and Eicosenoic acid (1.36%.). The groundnut oil was used in cookies preparation @ 25, 50, 75 and 100 % along with control (0% groundnut oil) and packed in HDPE bags for 2 months of storage at room temperature. The cookies were evaluated for physical, chemical, sensory and storage stability analyses. The moisture content, crude protein and Thiobarbituric acid (TBA) no. of cookies significantly varied as a function of storage, where as crude fiber, ash and NFE content of cookies varied non significantly. The width, thickness and spread factor of cookies varied significantly due to variation of groundnut oil in cookies. The results of the present investigations indicated that spices and groundnuts can be safely stored in polyethylene bags for their better quality retention. The use of radiation can be helpful for the preservation of spices and groundnuts with respect to the production of aflatoxin during storage.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Aflatoxin, Aspergillus flavus, Aspergillus parasiticus, Phenolics.|
|Subjects:||Engineering & Technology (e) > Technology (e2) > Food Technology(e2.2)|
|Deposited By:||Mr. Javed Memon|
|Deposited On:||07 Jan 2010 12:27|
|Last Modified:||07 Jan 2010 12:27|
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