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application/pdf, 論文(Article), ニホングリ(Castanea crenata Siebold & Zucc.)果実の長期貯蔵試験を2004年10月から2005年9月までポリエチレンフィルムを包装材として行った.処理区として包装材1枚区,2枚重ね区,5枚重ね区を設け,品質要因として可食部の可溶性糖含量,デンプン含量および微細構造を調査した.健全果率は貯蔵2か月後から大きく減少し,5枚区では貯蔵10か月の時点ですべての果実が商品価値を失った.袋内のガス組成は包装材の枚数が多い区ほど酸素濃度が低く,二酸化炭素濃度が高い値を示した. 果実の微細構造は貯蔵3か月で処理区間に大きな差異が観察された.すなわち,すべての処理区でデンプンの分解像が観察されたが,その進行程度は1枚区,2 枚区に比較し,5枚区で抑制されていた.5枚区では,袋内の低酸素・高二酸化炭素により果実の呼吸が抑えられ,結果としてデンプン分解が抑制されたと考えられた.最終調査日の1枚区および2枚区において,健全果ではデンプンの分解像が少なく,デンプン含量も高い値であった.この時点での健全果率は50%程度であったが,健全果ではデンプンの蓄積量が高いことから,収穫時におけるデンプン蓄積量,すなわち成熟度の高い果実ほど貯蔵性が高いことが示唆された., Long-term storage of Japanese chestnut (Castanea crenata Siebold & Zucc.) fruit using a polyethylene bag was carried out between October 2004 to September 2005. In order to create different O_2/CO_2 compositions in the bags, we used 1,2, or 5 layers of polyethylene bags. The concentrations of soluble sugars and starch and the microstructure of cotyledonary parenchyma cells were investigated as fruit quality factors. The rate of sound fruits was decreased for all treatments at 2 months of storage. When 5 layers of polyethylene bag were used, all fruits lost their commercial quality at 10 months of storage. At 3 months of storage, there were large differences in gas composition among the treatments. The higher number of polyethylene films facilitated a decrease in the O_2 content and increase in the CO_2 content. Scanning electron microscopic observation of cotyledonary parenchyma cells demonstrated that the degree of starch breakdown in each treatment was also different at 3 months of storage. Starch breakdown was extensive when 1 or 2 layers of polyethylene bag were used but was decreased when 5 layers of polyethylene bag were used. These morphological differences indicate that gas composition in the bags affects fruit respiration and reserves mobilization. The amyloplast density and starch concentration in sound fruits were relatively high at 11 months of storage when I and 2 layers of polyethylene bag were used. At this stage, although the sound fruits rate was low (approx. 50%), a high amount of storage reserves was retained in these fruits. These findings suggest that the amount of storage reserves in chestnut fruit at harvest affects fruit storability; in other words, well-matured fruits have a good potential for longterm storage.