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Studies were undertaken to determine the fate of the mycotoxins, fumonisins, during the process of alkaline cooking (nixtamalization), using normal-appearing corn that was naturally contaminated with fumonisin B(1) (FB(1)) at 8.79 ppm. Corn was processed into tortillas, starting with raw corn that was cooked with lime and allowed to steep overnight; the steeped corn (nixtamal) was washed and ground into masa, which was used to make tortillas. Calculations to determine how much of the original fumonisin remained in the finished products took into consideration that FB(1) will be converted to hydrolyzed fumonisin B(1) (HFB(1)) by the process of alkaline cooking. All fractions, including steeping and washing water, were weighed, and percent moisture and fumonisin content were determined. Tortillas contained approximately 0.50 ppm of FB(1), plus 0.36 ppm of HFB(1), which represented 18.5% of the initial FB(1) concentration. Three-fourths of the original amount of fumonisin was present in the liquid fractions, primarily as HFB(1). Nixtamalization significantly reduced the amount of fumonisin in maize.

The relative amounts of amylose and amylopectin in maize starch were determined in samples representing hard and soft endosperm. Although differences were small, amylose content differed significantly (P < 0.001 and P < 0.05) between the two types of endosperm, with hard endosperm containing a higher percentage of amylose. Scanning electron microscopy was used to determine that the surface appearance of starch granules from hard and soft endosperm differed. Starch granules from soft endosperm had randomly distributed pores on their surfaces, which had a rough appearance. Few pores were observed on granules from hard endosperm. A fairly common occurrence with starch granules from soft endosperm was the development of wrinkles or fissures upon prolonged exposure to the beam of the electron microscope. Thus, a correlation existed between endosperm hardness, amylose content, and susceptibility to wrinkling and fissures. The granules of the soft endosperm of maize, presumably less mature than the granules of the hard endosperm, have a lower amylose content (20.5 ± 1.9% vs. 23.0 ± 1.0%), exhibit more surface pores, and are more susceptible to wrinkling in an electron beam, compared with granules of the hard endosperm. Results suggested that the composition and internal architecture of the starch granule differ depending on the hardness of the endosperm from which it was obtained.

Two hundred twenty-eight male chicks (Columbia x New Hampshire) were given feed amended with autoclaved culture material (CM) of Fusarium proliferatum Containing fumonisin B1 (FB1), fumonisin B2 (FB2) and moniliformin in 3 separate feeding trials. Purified FB1 and moniliformin were given separately and in combination in a fourth feeding trial. Birds were given amended rations at day 1 (Trial 1 and 4), day 7 (Trial 2), and day 21 (Trial 3) and their respective ration was given for 28 days (Trial 1), 21 days (Trial 2), 7 days (Trial 3), and 14 days (Trial 4). FB1 concentrations were 546, 193, and 61 ppm; FB2 were 98, 38 and 14 ppm; and moniliformin were 367, 193, and 66 ppm in the first 3 feeding trial regimens. Chicks in Trial 4 were given dietary concentrations of purified FB1 at 274 and 125 ppm, and moniliformin at 154 and 27 ppm. FB1 and moniliformin, both alone and in combination, produced dose-responsive clinical signs, reduced weight gains and mortality in chicks. Age of birds given amended feeds had little difference in the clinical response; however, those given the rations from days 7 or 21 were slightly less susceptible than those given rations beginning at 1 day of age. Additive effects were noted when the toxins were given in combination. When toxins were given separately, adverse effects took longer to occur. A system to monitor pattern and rate of defecation (RD) was developed for assessing the chicks' approach to feed, water and heat source as illness progressed. Our results indicate that chicks fed corn heavily infected with F. proliferatum under field conditions could suffer acute death similar to that described for 'spiking mortality syndrome' during the first 3 weeks of age.

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Fumonisins, a family of mycotoxins produced by Fusarium moniliforme and Fusarium proliferatum, are found in maize worldwide and have been associated with animal diseases. There is concern that high dietary intake of a maize-based diet may expose people in Mexico and Central America to fumonisins. Nixtamalized maize products from Mexico and the United States were examined to evaluate methods for quantitation of the different forms of fumonisins. The chelating reagent EDTA (exceeding the calcium concentration by a factor of 1. 36) was added to enhance extraction of fumonisins because calcium remained in the samples as a result of processing. It was expected that the majority of the fumonisin detected would be in the hydrolyzed form, yet the highest level of hydrolyzed fumonisin B(1) detected was 0.1 ppm. The amount of fumonisin B(1) was significantly higher in Mexican samples (mean = 0.79 ppm) than in samples purchased in the United States (mean = 0.16 ppm).

Abstract. Two hundred twenty-eight male broiler chicks (Columbia x New Hampshire) were given feed amended with autoclaved culture material of Fusarium proliferatum containing fumonisin B 1 (FB 1 ) at 61, 193, and 546 ppm, fumonisin B 2 (FB 2 ) at 14, 38, and 98 ppm, and moniliformin at 66, 193, and 367 ppm in 3 separate feeding trials (amounts of toxin in each trial, respectively). Birds were started on amended rations at days 1, 7, and 21 and continued on their respective ration until they were 28 days old. Purified FB 1 (125, 274 ppm) and moniliformin (27, 154 ppm) were given separately and in combination (137 and 77 ppm, respectively), starting on day 1 and continuing for 14 days. Of serum chemistry parameters, only glucose was significantly decreased. Significant increases were noted in serum cholesterol, sodium, alkaline phosphatase, aspartate amiparameters, significant decreases were noted in red blood cell counts, hemoglobin, packed cell volume, and white blood cell counts. Immunologic changes included impaired anti-Newcastle disease antibody hemagglutination inhibition titers associated with relative decreases in total serum globulins and increases in albumin/ globulin ratios. The changes were noted in all treatment groups when compared to controls.Fumonisins B 1 (FB 1 ) and B 2 (FB 2 ) are mycotoxins produced by Fusarium moniliforme and a closely related species, Fusarium proliferatum.

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