Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality.
The growth of filamentous fungi during the spontaneous cocoa bean fermentation leads to inferior cocoa bean quality and poses a health risk for consumers due to the potential accumulation of mycotoxins. We recently developed anti-fungal cultures with the capacity to inhibit the growth of mycotoxigen...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2020-01-01
|
| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0239365 |
| _version_ | 1818588906631725056 |
|---|---|
| author | Edwina Romanens Vasilisa Pedan Leo Meile Susanne Miescher Schwenninger |
| author_facet | Edwina Romanens Vasilisa Pedan Leo Meile Susanne Miescher Schwenninger |
| author_sort | Edwina Romanens |
| collection | DOAJ |
| description | The growth of filamentous fungi during the spontaneous cocoa bean fermentation leads to inferior cocoa bean quality and poses a health risk for consumers due to the potential accumulation of mycotoxins. We recently developed anti-fungal cultures with the capacity to inhibit the growth of mycotoxigenic filamentous fungi on cocoa beans. However, it is not clear how these anti-fungal cultures affect the fermentation process and cocoa bean quality. For that, the anti-fungal co-cultures, Lactobacillus fermentum M017-Saccharomyces cerevisiae H290 (A) and Lb. fermentum 223-S. cerevisiae H290 (B), were applied to 180-kg box fermentations in Honduras in three time-independent replications each including a spontaneous control fermentation. The comparison of inoculated and spontaneous fermentation processes revealed that the co-cultures only marginally affected the fermentation process and cocoa bean quality. Microorganisms reached maximal levels of 6.2-7.6 log CFU/g of yeasts and acetic acid bacteria and 7.9-9.5 log CFU/g of lactic acid bacteria during all fermentations and led to maximal metabolite concentrations in bean cotyledons of 4-12 mg/g ethanol, 2-6 mg/g lactic acid and 6-14 mg/g acetic acid. The fermentation and drying processes resulted in 38-90 mg epicatechin equivalents/g in the cotyledons of dried beans. However, the co-cultures led to up to ten times higher mannitol levels in cotyledons of inoculated beans compared to beans during spontaneous fermentation, and caused a slower fermentation process, detectable as up to 8-12 °C lower temperatures in the centre of the fermenting pulp-bean mass and up to 22% lower proportions of well-fermented beans after drying. Co-culture B-with Lb. fermentum 223 -led to improved cocoa bean quality compared to co-culture A-with Lb. fermentum M017 -, i.e. cocoa beans with 0.5-1.9 mg/g less acetic acid, 4-17% higher shares of well-fermented beans and, on a scale from 0 to 10, to 0.2-0.6 units lower astringency, up to 1.1 units lower off-flavours, and 0.2-0.9 units higher cocoa notes. Therefore, the anti-fungal co-culture B is recommended for future applications and its capacity to limit fungal growth and mycotoxin production during industrial-scale cocoa bean fermentation should be investigated in further studies. |
| first_indexed | 2024-12-16T09:32:12Z |
| format | Article |
| id | doaj.art-460d91995ca645db8e0fe987e0df23e9 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-16T09:32:12Z |
| publishDate | 2020-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-460d91995ca645db8e0fe987e0df23e92022-12-21T22:36:30ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-011510e023936510.1371/journal.pone.0239365Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality.Edwina RomanensVasilisa PedanLeo MeileSusanne Miescher SchwenningerThe growth of filamentous fungi during the spontaneous cocoa bean fermentation leads to inferior cocoa bean quality and poses a health risk for consumers due to the potential accumulation of mycotoxins. We recently developed anti-fungal cultures with the capacity to inhibit the growth of mycotoxigenic filamentous fungi on cocoa beans. However, it is not clear how these anti-fungal cultures affect the fermentation process and cocoa bean quality. For that, the anti-fungal co-cultures, Lactobacillus fermentum M017-Saccharomyces cerevisiae H290 (A) and Lb. fermentum 223-S. cerevisiae H290 (B), were applied to 180-kg box fermentations in Honduras in three time-independent replications each including a spontaneous control fermentation. The comparison of inoculated and spontaneous fermentation processes revealed that the co-cultures only marginally affected the fermentation process and cocoa bean quality. Microorganisms reached maximal levels of 6.2-7.6 log CFU/g of yeasts and acetic acid bacteria and 7.9-9.5 log CFU/g of lactic acid bacteria during all fermentations and led to maximal metabolite concentrations in bean cotyledons of 4-12 mg/g ethanol, 2-6 mg/g lactic acid and 6-14 mg/g acetic acid. The fermentation and drying processes resulted in 38-90 mg epicatechin equivalents/g in the cotyledons of dried beans. However, the co-cultures led to up to ten times higher mannitol levels in cotyledons of inoculated beans compared to beans during spontaneous fermentation, and caused a slower fermentation process, detectable as up to 8-12 °C lower temperatures in the centre of the fermenting pulp-bean mass and up to 22% lower proportions of well-fermented beans after drying. Co-culture B-with Lb. fermentum 223 -led to improved cocoa bean quality compared to co-culture A-with Lb. fermentum M017 -, i.e. cocoa beans with 0.5-1.9 mg/g less acetic acid, 4-17% higher shares of well-fermented beans and, on a scale from 0 to 10, to 0.2-0.6 units lower astringency, up to 1.1 units lower off-flavours, and 0.2-0.9 units higher cocoa notes. Therefore, the anti-fungal co-culture B is recommended for future applications and its capacity to limit fungal growth and mycotoxin production during industrial-scale cocoa bean fermentation should be investigated in further studies.https://doi.org/10.1371/journal.pone.0239365 |
| spellingShingle | Edwina Romanens Vasilisa Pedan Leo Meile Susanne Miescher Schwenninger Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. PLoS ONE |
| title | Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. |
| title_full | Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. |
| title_fullStr | Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. |
| title_full_unstemmed | Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. |
| title_short | Influence of two anti-fungal Lactobacillus fermentum-Saccharomyces cerevisiae co-cultures on cocoa bean fermentation and final bean quality. |
| title_sort | influence of two anti fungal lactobacillus fermentum saccharomyces cerevisiae co cultures on cocoa bean fermentation and final bean quality |
| url | https://doi.org/10.1371/journal.pone.0239365 |
| work_keys_str_mv | AT edwinaromanens influenceoftwoantifungallactobacillusfermentumsaccharomycescerevisiaecoculturesoncocoabeanfermentationandfinalbeanquality AT vasilisapedan influenceoftwoantifungallactobacillusfermentumsaccharomycescerevisiaecoculturesoncocoabeanfermentationandfinalbeanquality AT leomeile influenceoftwoantifungallactobacillusfermentumsaccharomycescerevisiaecoculturesoncocoabeanfermentationandfinalbeanquality AT susannemiescherschwenninger influenceoftwoantifungallactobacillusfermentumsaccharomycescerevisiaecoculturesoncocoabeanfermentationandfinalbeanquality |