Japanese chestnuts: harvest management and thermal treatment for reducing post-harvest fungal deterioration and for the crop sustainability

Abstract

The Japanese chestnuts are typically seasonal fruit that keeps its good commercial quality, turgor and sanity for a relatively short period of time. One of the main difficulties in marketing is its high perishability due to its high moisture content. This characteristic, combined with their chemical constitution, makes moulding deterioration one of the most serious post-harvest problems. In Brazil, the chestnut Castanea crenata (Sieb. et Zucc.) was introduced by Japanese immigrants in the early 1970s. Since then, 13 varieties have being grown commercially in 20 cities of São Paulo State. However, farmers do not submit the product to any decontamination process and for this reason the product deteriorates 5 days after harvest. Therefore, after years of investment, some farmers are giving up this culture and plan to cut the trees. Heat treatment is a sustainable decontamination technology because; in addition to fungal control it also may eradicate insect infestation. This research aims to (1) assess the level of reduction in fungal contamination in chestnuts collected from the tree when compared with those collected from the ground (2) evaluate the effect of heat treatments for controlling postharvest fungal decay (3) determine the effect of the proposed treatments on fungal deterioration control and fruit quality during refrigerated storage (1°C/90%R.H.). (AU)