The 2012 ASHS Annual Conference

Shell-on, fresh chestnuts are currently sold in macro perforated polybags. This package does not protect chestnuts from damage, contamination or weight loss. Protection from damage and reduction in weight loss are expected using closed rigid containers. However, the environment created may promote microbial growth at retail temperatures. The retail shelf life of two shell-on products, one a European/Japanese hybrid cultivar (‘Colossal’) and the other a harvested group of non-cultivar Chinese chestnuts, was assessed in rigid, snap-fit containers and macro-perforated polybags by analyzing weight loss, soluble solid contents, bacterial and fungal growth, color, and headspace. The impact of two packaging materials—petroleum-based polyethylene terephthalate (PET) and bio-based polylactic acid (PLA) (weaker moisture barrier)—on chestnut shelf-life was also assessed under retail conditions. In order to simulate retail storage conditions, the packages were held for 10 h at 60 °F (display shelving) followed by 14 h at 35 °F (back storage room) for 6 weeks. ‘Colossal’ chestnuts had a higher weight loss, higher soluble solids content, and higher respiration rate and were more sensitive to bacterial growth than Chinese chestnuts (P < 0.05). Rigid containers reduced weight loss up to 13% compared to the commercial polybags. Chestnuts in rigid containers also had more stable soluble solids content (P < 0.05). Less bacterial growth but greater fungal growth was observed in Chinese chestnuts in rigid containers compared to polybags (P < 0.05). However, no significant differences (P > 0.05) in fungal growth were seen across all packages for ‘Colossal’ chestnuts. Across the packaging materials, differences in weight loss (only for Chinese chestnuts, P < 0.05), gas composition (P < 0.05) and condensation removal were observed. In conclusion, rigid containers can help to ensure that the package content fulfills the weight specification given on labels and better preserve chestnut quality.