Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels

Aflatoxin contamination in stored crops poses a serious threat to public health and food safety, particularly in tropical regions where warm, humid conditions favour fungal growth. Cassava, a staple in many developing countries, is vulnerable to aflatoxin B1 (AFB1) contamination during storage, nece...

Descripción completa

Detalles Bibliográficos
Autores principales: Oyesigye, E., Cervini, C., Nkurunungi, J.B., Medina, A., Mahuku, G.
Formato: Journal Article
Lenguaje:Inglés
Publicado: 2025
Materias:
Acceso en línea:https://hdl.handle.net/10568/179034
_version_ 1855534932832550912
author Oyesigye, E.
Cervini, C.
Nkurunungi, J.B.
Medina, A.
Mahuku, G.
author_browse Cervini, C.
Mahuku, G.
Medina, A.
Nkurunungi, J.B.
Oyesigye, E.
author_facet Oyesigye, E.
Cervini, C.
Nkurunungi, J.B.
Medina, A.
Mahuku, G.
author_sort Oyesigye, E.
collection Repository of Agricultural Research Outputs (CGSpace)
description Aflatoxin contamination in stored crops poses a serious threat to public health and food safety, particularly in tropical regions where warm, humid conditions favour fungal growth. Cassava, a staple in many developing countries, is vulnerable to aflatoxin B1 (AFB1) contamination during storage, necessitating effective mitigation strategies. This study evaluated the efficacy of sodium metabisulphite (NaMBS) sheets, which slowly release sulphurdioxide (SO2), in reducing aflatoxigenic fungal load and aflatoxin B1 (AFB1) concentrations in cassava chips (sliced pieces of cassava root used for cassava flour production). Storage trials were conducted in three Ugandan districts with contrasting climates, using two bag types: traditional polypropylene and hermetic Purdue Improved Crop Storage (PICS) bags-with and without NaMBS. The study employed a three-way factorial randomized complete block design (bag type, NaMBS treatment, and district). Fungal load and AFB1 were monitored for 30 days using DG-18 media and LC-MS/MS, respectively. Aspergillus section Flavi showed the highest initial fungal load (3.57 × 106 cfu/g), which significantly (P < 0.01) decreased after NaMBS treatment. A significant bag × NaMBS interaction (P < 0.001) was observed, with PICS bags consistently outperforming traditional bags. District climate did not significantly affect fungal counts (P = 0.06) but strongly influenced AFB1 levels (P < 0.01). Untreated traditional bags showed the highest AFB1 (146.6 μg/kg), while NaMBS-treated PICS bags reduced AFB1 to 0.23 μg/kg, representing up to 99.9 % reduction. These findings provide foundational evidence that NaMBS sheets can effectively suppress aflatoxigenic fungi and reduce AFB1 contamination in cassava stores. Further work should assess residual NaMBS safety and consumer acceptability.
format Journal Article
id CGSpace179034
institution CGIAR Consortium
language Inglés
publishDate 2025
publishDateRange 2025
publishDateSort 2025
record_format dspace
spelling CGSpace1790342025-12-19T01:37:18Z Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels Oyesigye, E. Cervini, C. Nkurunungi, J.B. Medina, A. Mahuku, G. cassava manihot esculenta aflatoxin B1 food safety food security aflatoxins fungi Aflatoxin contamination in stored crops poses a serious threat to public health and food safety, particularly in tropical regions where warm, humid conditions favour fungal growth. Cassava, a staple in many developing countries, is vulnerable to aflatoxin B1 (AFB1) contamination during storage, necessitating effective mitigation strategies. This study evaluated the efficacy of sodium metabisulphite (NaMBS) sheets, which slowly release sulphurdioxide (SO2), in reducing aflatoxigenic fungal load and aflatoxin B1 (AFB1) concentrations in cassava chips (sliced pieces of cassava root used for cassava flour production). Storage trials were conducted in three Ugandan districts with contrasting climates, using two bag types: traditional polypropylene and hermetic Purdue Improved Crop Storage (PICS) bags-with and without NaMBS. The study employed a three-way factorial randomized complete block design (bag type, NaMBS treatment, and district). Fungal load and AFB1 were monitored for 30 days using DG-18 media and LC-MS/MS, respectively. Aspergillus section Flavi showed the highest initial fungal load (3.57 × 106 cfu/g), which significantly (P < 0.01) decreased after NaMBS treatment. A significant bag × NaMBS interaction (P < 0.001) was observed, with PICS bags consistently outperforming traditional bags. District climate did not significantly affect fungal counts (P = 0.06) but strongly influenced AFB1 levels (P < 0.01). Untreated traditional bags showed the highest AFB1 (146.6 μg/kg), while NaMBS-treated PICS bags reduced AFB1 to 0.23 μg/kg, representing up to 99.9 % reduction. These findings provide foundational evidence that NaMBS sheets can effectively suppress aflatoxigenic fungi and reduce AFB1 contamination in cassava stores. Further work should assess residual NaMBS safety and consumer acceptability. 2025-04 2025-12-19T01:37:17Z 2025-12-19T01:37:17Z Journal Article https://hdl.handle.net/10568/179034 en Limited Access Oyesigye, E., Cervini, C., Nkurunungi, J.B., Medina, A. & Mahuku, G. (2025). Field experiment in Ugandan cassava stores reveals that slow release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels. Food Control, 182: 111797, 1-10.
spellingShingle cassava
manihot esculenta
aflatoxin B1
food safety
food security
aflatoxins
fungi
Oyesigye, E.
Cervini, C.
Nkurunungi, J.B.
Medina, A.
Mahuku, G.
Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title_full Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title_fullStr Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title_full_unstemmed Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title_short Field experiment in Ugandan cassava stores reveal that slow-release SO2 sheets suppress aflatoxigenic fungi, resulting in undetectable aflatoxin B1 levels
title_sort field experiment in ugandan cassava stores reveal that slow release so2 sheets suppress aflatoxigenic fungi resulting in undetectable aflatoxin b1 levels
topic cassava
manihot esculenta
aflatoxin B1
food safety
food security
aflatoxins
fungi
url https://hdl.handle.net/10568/179034
work_keys_str_mv AT oyesigyee fieldexperimentinugandancassavastoresrevealthatslowreleaseso2sheetssuppressaflatoxigenicfungiresultinginundetectableaflatoxinb1levels
AT cervinic fieldexperimentinugandancassavastoresrevealthatslowreleaseso2sheetssuppressaflatoxigenicfungiresultinginundetectableaflatoxinb1levels
AT nkurunungijb fieldexperimentinugandancassavastoresrevealthatslowreleaseso2sheetssuppressaflatoxigenicfungiresultinginundetectableaflatoxinb1levels
AT medinaa fieldexperimentinugandancassavastoresrevealthatslowreleaseso2sheetssuppressaflatoxigenicfungiresultinginundetectableaflatoxinb1levels
AT mahukug fieldexperimentinugandancassavastoresrevealthatslowreleaseso2sheetssuppressaflatoxigenicfungiresultinginundetectableaflatoxinb1levels