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Authors: Iqbal, Shahzad Z.
Keywords: Natural Sciences
Chemistry & allied sciences
Issue Date: 2011
Abstract: Chili is an important spice and used as salad, complementary dish, medicine, industrial product, or as decoration. It is consumed as fresh, dry, powder, paste or as sauce. It enhances food palatability, inducing the consumption of other foods. It is a rich source of Vitamin A & C. In Asia, chili is an important component in the cropping system. In terms of area, it is ranked first in Asia and third in the world as most important vegetable. Chilies are subject to various pest and disease constraints to optimal production. The contamination of the crops with mycotoxins from the growth of Aspergillus flavus and/or Aspergillus parasiticus is one of the most serious problems. Mycotoxins are secondary metabolites of fungi. Due to the widespread distribution of fungi in the environment, mycotoxins are considered to be one of the most important contaminants of foods and feeds. Aflatoxins are important class of mycotoxins. The toxins can be produced in the field prior to harvest, or alternatively, can arise due to fungal growth under poor storage conditions. Mycotoxins can produce both in temperate and tropical regions of the world, depending on the species of fungi. The extraction, clean up and analysis methodology for aflatoxins in chilies were validated and found it efficient and good in respect of recovery, reproducibility, repeatability, resolution and cost-effective. The collected chili samples from Faisalabad Division, Pakistan exhibited high level of aflatoxins but after treatment with γ-irradiation, more than 95% reduction in AFB 1 and ≥ 97% in Total (∑AFB 1 + AFB 2 +AFG 1 + AFG 2 ) were observed at a dose of 6 kGy. Citric acid was effective for the reduction of AFs in chilies and reduced 89% AFB 1 and 90% total AFs in contaminated chilies. Propionic acid is also used for the reduction of AFs in red chilies and it reduced 80% AFB 1 and 76% total AFs in chilies. Antioxidants like butylated hydroxyl-anisole (BHA) and butylated hydroxyl-toluene (BHT) were effective to reduce fungal load and the of (20:20 mM) of BHA and BHT were inhibit 100% of fungal load in malt extract agar of chilies. From the results it is evident that among aflatoxin reduction techniques, γ-irradiation is a good technology to remove contaminants like AFs from chilies. The food quality of irradiated cereals was evaluated to study any chemical change in vitamin E and fungal biomass. The total biomass (CFU g -1 ) showed linear behavior as increasing the dose level of gamma irradiation. In some samples of chilies, no microflora (fungi) was observed after 72 h. of incubation. From the results however, it is revealed that with increasing γ-irradiation doses a decrease in vitamin E content was observed in chilies but this decrease is not significant (p > 0.05). In the present study, phenolics, flavonoids and antioxidant activity of chilies and selected spices (cloves, turmeric, oregano, black pepper and cinnamon) have been evaluated in the Department of Food Science, Cornell University, USA. From the results, it has been evident that chilies and spices are good source of antioxidants. Special attention is urgently needed to create awareness of the high level of AFs contamination in chilies, among farmers, consumers, and traders. Special emphasis should also be given to adopt GHP and GSP in order to minimize the toxin in chilie
Appears in Collections:PhD Thesis of All Public / Private Sector Universities / DAIs.

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