Date of Award

1997

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

School of Nutrition and Food Sciences

First Advisor

Douglas L. Park

Abstract

Aflatoxins and fumonisins, secondary mold metabolites, occur naturally as co-contaminants in corn. Health and economic risks associated with this contamination of food and feed have been the focus of much research worldwide. Research programs resulting from the discovery of aflatoxins in the 1960's has been used to guide study programs for fumonisins. The establishment of food safety programs, including mycotoxin decontamination procedures, must be evaluated for further application. The evaluation of selected procedures which reduce the risks associated with the contamination of these mycotoxins in food utilized for human and animal consumption was the focus of this study. This study investigated the possible risk reduction of naturally contaminated and spiked corn with aflatoxin B$\sb1$ and fumonisin B$\sb1,$ utilizing conventional and modified industrial processes. Several ammonium based FDA-approved food additives (ammonium chloride, ammonium persulfate, and ammonium hydroxide) and their combination with hydrogen peroxide were utilized during normal fermentation and nixtamalization processes. HPLC C$\sb{18}$ reverse phase procedures were utilized for the detection and quantification of both toxins. Reduction of aflatoxin B$\sb1$ levels was observed with all chemicals evaluated in this study. Fumonisin B$\sb1$ was not detected in any of the final products. The combination of ammonium persulfate with hydrogen peroxide, and ammonium hydroxide alone were the most effective additives. Tortillas prepared with modified nixtamalization (ammonium hydroxide, 1% v/w) was selected for evaluation, i.e., determination of teratogenicity and mutagenicity of reaction products, and sensory evaluation of prepared tortillas. Teratogenicity and acute toxicity potentials of naturally contaminated samples were determined using a chicken embryo assay. Mutagenicity of the samples was measured with the Salmonella/microsomal mutagenicity assay utilizing test Strains TA 98, TA 100, and TA 102. The sensory evaluation study used semi-trained panelists for using the triangle test protocol. Results of the study showed no teratogenic potential in normal nixtamalized versus the modified nixtamalized processes for aflatoxin contaminated corn. Mutagenicity assay results were inconclusive and will require further study. Sensory evaluation demonstrated high acceptable levels of the product. These results support the need for more research in the area of decontamination procedures utilizing conventional processes and food additives.

ISBN

9780591458435

Pages

136

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