Chestnut fruits in high-CO2-modified atmosphere

Chestnuts are typical seasonal fruits that are perishable and maintain their optimal commercial quality for only a relatively brief period. The most common postharvest method consists of cold or hot water treatment, which was developed in Italy during the 1930s. The goal of this study was to store fresh chestnuts for a maximum period of 90 days at 1±1°C and 90-95% relative humidity (RH) using a modified atmosphere (MA; 80% CO2, 15% N2, 5% O2). The hybrid cultivar ‘Bouche de Betizac’ (C. sativa Mill. × C. mollissima Blume) and the European chestnut ‘Garrone Nero’ (C. sativa Mill.) were obtained from the Agrifrutta Soc. Coop. SRL (Piedmont, Italy) commercial orchard and stored in pallet bags in a CO2-enriched atmosphere. Two different types of materials, a traditional polyethylene film (120 µm thick) and a bio-based film derived from starch (180 µm thick), were used to maintain the MA. For controls, chestnuts were treated with a cold-water bath and stored under normal atmospheric (NA) conditions. The MA storage was evaluated based on the evolution of the gas inside the storage environment and the water content (%), marketability (%), and starch content (%) of fruits. Both cultivars exhibited a low water content (%) under MA storage conditions. The starch content does not appear to be influenced by the MA. The ‘Bouche de Betizac’ fruits were considered marketable after up to 60 days of storage, whereas the ‘Garrone Nero’ fruits remained marketable for up to 90 days. Thus, the use of a high-CO2-modified atmosphere is a possible alternative to a cold-water bath for storing fresh chestnut fruits.