Sweet chestnut fruits are popular fruits commercialized as fresh or processed ready-to-eat
products. The major post-harvest problems associated with stored chestnut fruits are fungal rots,
which cause major losses in fruit quality. The aims of this work were to determine the incidence,
abundance and diversity of rots and fungi in three chestnut varieties (Longal, Judia and Martaínha)
of Portugal, collected from an industrial plant, and to identify the stages of storage and processing
where fungi and rots are more significant. Thirty-three chestnut samples from the three varieties were
collected from different stages of industrial processing. Nuts were internally and externally inspected
for damage, infestation and infection, and internal fungi were isolated and molecularly identified.
The variety Martaínha was identified as the least susceptible to fungal growth, while Longal was
the most susceptible. A high diversity of fungi was detected and identified. The dominant fungi
were Mucor racemosus, Penicillium spp. (the causal agents of green rots), Ciboria batschiana (black
rot) and Botrytis cinerea (gray rot). Gnomoniopsis smithogilvyi, the causal agent of brown rot, was
also frequently detected. Sterilization with hydrothermal bath was effective in the elimination or
reduction of most of the rot-causing fungi. These results could serve as a baseline for better monitoring
fungal development and chestnut decay, and to develop effective management measures to control
post-harvest chestnut rots.
This work was funded by the project “ValorCast—Valorização da castanha e otimização
da sua comercialização”, ref. PDR2020-101-032030, funded by Fundo Europeu Agrícola de Desenvolvimento
Rural (FEADER) and the Portuguese government, under the scope of Ação 1.1 “Grupos
Operacionais”, Medida 1. “Inovação”, PDR 2020—Programa de Desenvolvimento Rural do Continente.
The Foundation for Science and Technology (FCT, Portugal) and FEDER under Program
PT2020 provided financial support to CIMO (UID/AGR/00690/2020), SusTEC (LA/P/0007/2020),
CITAB (UID/AGR/04033/2020) and Inov4Agro (LA/P/0126/2020).
