Pakistan Research Repository


Title of Thesis Occurrence of Aflatoxin in Groundnut and Spices During Storage
Author(s) Muhammad Abrar
Institute/University/Department Details National Institute of Science and Technology, University of Agriculture, Faislabad.
Session 2009
Subject Food Technology
Number of Pages 170
Keywords (Extracted from title, table of contents and abstract of thesis) Aflatoxin, Aspergillus flavus, Aspergillus parasiticus, Phenolics.
Abstract 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.


Download Full Thesis				676 KB

S. No.	Chapter	Title of the Chapters	Page	Size (KB)

1	1	Introduction	1	107 KB

2	2	Review of Literature	7	175 KB
	2.1	History	7
	2.2	Morphological characteristics	9
	2.3	Biosynthesis	9
	2.4	Occurrence	10
	2.5	Legislations	11
	2.6	Metabolism	12
	2.7	Toxicity of aflatoxins	14
	2.8	Aflatoxins in spices	21
	2.9	Aflatoxin in groundnut	21
	2.10	Effect of gamma irradiation on aflatoxin production	25
	2.11	Effect of storage conditions on aflatoxin production	27

3	3	Materials and Methods	30	165 KB
	3.1	Procurement of raw materials	30
	3.2	Storage of groundnut and spices	30
	3.3	Proximate analyses	30
	3.4	Packaging and storage of samples	32
	3.5	Irradiation	33
	3.6	Mycological Studies	33
	3.7	Total phenolics	35
	3.8	Determination of Aflatoxins	35
	3.9	Extraction of groundnut oil	36
	3.10	Refining of oil	37
	3.11	Physico-Chemical analysis	37
	3.12	Fatty acid profile	41
	3.13	Utilization of groundnut oil in cookies	42
	3.14	Preparation of cookies	42
	3.15	Analysis of raw material and final product	42
	3.16	Physical analysis of cookies	43
	3.17	Sensory evaluation	43
	3.18	Statistical analysis	44

4	4	Results and Discussion	45	479 KB
	4.1	Effect of packaging materials, storage conditions and duration on different quality attributes of spices and groundnuts	45
	4.2	Effect of storage period and irradiation doses on contaminated spices and groundnuts	71
	4.3	Characteristics of Groundnut Oil (GNO)	100

		Summary	120	80 KB

		Literature Cited	124	184 KB

		Appendix	146	117 KB