Quality changes of Ruaner pear at frozen storage process

The quality changes in Ruaner pear (Pyrus ussuriensis maxim), a typical pear species in Qinghai province, were analyzed by determining its soluble solids content, hardness, Vc content and other factors at different storage period under frozen storage conditions. And the changes of stone cell were also studied through microscopic observation by using paraffin technology. The results showed that: the soluble solids content, water content and stone cells content has a downward trend but there is no significant difference. Vc contents increased in initial stage and then declined. The stone cells were discrete-shaped and smaller while the flesh was thinner. These dramatic changes were caused its unique food flavor, but little vary of its quality after frozen storage.