Quality Changes of Muscat of Alexandria Table Grapes as Influenced by Postharvest Cluster Stem Excision

In 2003 and 2004, the potential of using table grapes, cv. Muscat of Alexandria, as fresh-cut products was cvaluated by investigating the effects of postharvest cluster stem excision on several quality attributes. Clusters were harbester either at 17 or 19℃Brix from mature grapevines grown in Okayama, Japan. The treatments included: (1) No excision (C): Intact clusters; (2) Excision at Iaterals (L); Branches carrying 2-7 berries; and (3) Excision at pedicels (P): Single berries without pedicels. Fruit was placed in commercial packages and stored for 6 days 25℃. As regards aroma, linalool production by P increased markedly without major changes in the other monoterpenes. In addition, high geraniol production was observed in C, while minor aroma changes ware observed in L. Total amino acid concentrations increased in P and C in comparison to L. Interestingly, at the end of the experiment, berries of treatment P had the highest firmness and visual quality, followed by C, while L was the lowest. It is concluded that grapes of Muscat of Alexandria are suitable for stemless marketing.

マスカット・オブ・アレキサンドリアの果房がカットフルーツとして適するかどうかを，2003年と2004年に検討し た．岡山で生産された完熟した果房を，房全体のまま（果房），穂軸を切り離して２―７果粒の小房に切り分け（切り 房），小果梗で切り離して個々の果粒に切り分け（果粒），の３区とした．これらを箱詰めし，25℃で６日間，保蔵し た．保蔵中の果実の品質変化を分析した結果，主要な香気成分であるリナロールは果粒ごとの区で最も大きく増加し， ゲラニオールの増加は果房のままの区で大きかった．全アミノ酸含量の増加は，切り房区に比べて果粒区と果房区で 大きかった．しかし，果粒区では保蔵後の果粒硬度が最も高く，外観も優れ，次いで果房区，切り房区の順であった． 以上の結果から，マスカット果房を小果梗で切除し，果粒単位の状態で出荷することによって品質を最も高く保つこ とが可能である