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| Author(s): |
Luísa Freire
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2020-03-02 |
| Examining board members: |
Anderson de Souza Sant'Ana;
Liliana de Oliveira Rocha;
Adriana Pavesi Arisseto Bragotto;
Alessandra Regina da Silva;
Marina Venturini Copetti
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| Advisor: | Anderson de Souza Sant'Ana; Rodrigo Ramos Catharino |
| Abstract | |
Ochratoxin A (OTA) is the main mycotoxin contaminating grapes and its products, being responsible for several harmful effects on health. In addition to OTA, some modified forms may occur as a result of reactions taken place during processing, due to microbial transformation or the metabolism of plants. In view of this issue, this study aimed to determine the variability of fungal growth and production of OTA and its modified forms by strains of "Aspergillus niger" and "A. carbonarius"; and evaluate the variability of formation and degradation of OTA and its modified forms during winemaking. "A. carbonarius" and "A. niger" strains were incubated in grape-based medium. The determination of OTA was performed by high-performance liquid chromatography, and a high-resolution mass spectrometry was used for the detection of modified ochratoxin. The highest production of OTA was detected on day 15, and a decline on day 21 was observed. Among the targets sought, we identified only ethylamide ochratoxin A produced by strain CCDCA10443 (A. niger) on day 21 in grape-based medium. A conidia suspension of A. niger and A. carbonarius was inoculated on grapes of three varieties (Syrah, Touriga Nacional and Muscat Italia). A positive correlation was observed between the following grapes physicochemical parameters: pH, total soluble solids, total glycosides in glucose, total anthocyanin and OTA levels produced by "A. niger" and "A. carbonarius". Among the elected targets, we identified the decarboxy ochratoxin A in Muscat Italia variety at veraison and 15 days after the beginning of veraison stages; and ethylamide ochratoxin A in the Syrah variety at the ripeness stage. To detect the formation of modified ochratoxins in the presence of S. cerevisiae strains, high resolution mass spectrometry was used... The abstract is available with the full electronic document (AU) | |
| FAPESP's process: | 16/21041-5 - Fungi and modified mycotoxins in grapes and wines: modeling the variability of formation, stability during the processing and health effects |
| Grantee: | Luisa Freire Colombo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |