Relationship between oxygen concentration in endogenous gas beneath potato skin and blackspot bruise.

我国马铃薯产量为400万吨，其中70%产于北海道。加工用马铃薯的消费增加了西方化的饮食习惯，马铃薯黑斑瘀伤是马铃薯加工行业的严重问题。本研究以黑斑病抗性品种(Hokkaikogane)、中黑斑病品种(丰四郎、Toya)和感病品种(Norin-Ichigo、Danshaku-IMO)为材料，对黑斑病的发生机理进行了研究。测定马铃薯多酚氧化酶(PPO)活性、酚含量、薯皮破碎力、马铃薯破碎力和块茎内源气体含量时，PPO对块茎挫伤的贡献最大，其次是破损量、酚含量和破碎力。此外，感病品种的O2浓度较小，而CO2浓度较高。因此，这项研究表明，培育具有坚硬皮肤和组织的马铃薯品种，并在抑制呼吸的同时，储存和处理马铃薯，对于抑制瘀伤是重要的。

The potato production of our country is 4,000,000 tons, and 70% is produced in Hokkaido among those. The consumption of the potato for the processing increases westernizing eating habits, and the blackspot bruise of potatoes is a serious problem in potato processing industries. In this study, the mechanism for the blackspot bruise was investigated using the blackspot resistant (Hokkaikogane), middle (Toyoshiro, Toya) and susceptible (Norin-ichigo, Danshaku-imo) varieties. When the polyphenol oxidase (PPO) activity, phenol content, rapture force of potato skin, destruction load of potato, and endogenous gas inside potato tuber were measured, the PPO was the heist contribution to the bruise, followed by the destruction load, phenol content and rapture force. In addition, the O2 concentration was smaller in the susceptible variety while the CO2 was higher. Therefore, this study revealed that it was important for suppressing the bruise to develop potato varieties with hard skin and tissue, and to store and handle potatoes as much as suppressing the respiration.