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Molds and Tenuazonic Acid in Fresh Tomatoes Used for Catsup Production
Philip B Mislivec1, Verneal R Bruce1, Michael E Stack1
1Division of Microbiology and Division of Contaminants Chemistry, Food and Drug Administration, Washington, D.C. 20204.
Abstract:
The mold flora was determined for 146 samples of fresh but visibly moldy tomatoes collected from sorting belts in tomato catsup processing plants in California and in Midwestern and Eastern United States. Mold found in 141 of the samples included at least 22 genera, principally Alternaria , Aspergillus , Cladosporium , Fusarium and Penicillium , and 51 species. The California tomatoes were dominated by Geotrichum candidum and species of Aspergillus and Penicillium ; Midwest and East tomatoes were dominated by Alternaria . This suggested that the predominant molds in tomatoes may differ, depending on geographical source. Tenuazonic acid (TA), a toxic metabolite of Alternaria spp., was found in 73 of the samples at a range of 0.4 to 69.7 (average 4.94) μg/g of moldy tissue; however, Alternaria spp. were not found in 35 of the 73 TA-positive samples. It is possible that other molds may produce TA or that the toxin-producing Alternaria died off before our sampling.
Insights
Mold contamination in tomatoes varies by region, with California samples showing different dominant species than Midwest/East. Tenuazonic acid was detected, but not always alongside Alternaria molds.
Area of Science:
- Food microbiology
- Mycology
- Plant pathology
Background:
- Mold contamination is a concern in tomato processing.
- Identifying mold flora and mycotoxins is crucial for food safety.
Purpose of the Study:
- To characterize the mold flora in processing tomatoes.
- To detect the mycotoxin Tenuazonic acid (TA) in moldy tomatoes.
- To investigate geographical differences in mold prevalence.
Main Methods:
- Analysis of 146 moldy tomato samples from processing plants.
- Identification of mold genera and species.
- Quantification of Tenuazonic acid using established methods.
Main Results:
- 141 samples contained mold from 22 genera and 51 species.
- California tomatoes were dominated by Geotrichum candidum, Aspergillus, and Penicillium.
- Midwest and East tomatoes were predominantly contaminated with Alternaria.
- Tenuazonic acid was found in 73 samples, but Alternaria was absent in 35 of these.
Conclusions:
- Geographical location influences the predominant mold species in tomatoes.
- The presence of Tenuazonic acid may not always correlate with detectable Alternaria.
- Further research is needed to understand TA production by other fungi or the viability of Alternaria.
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