I=
Pakistan Research Repository Home
 

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