Fishermen put the fresh shrimp into a liquid-nitrogen instant freezer on a ship in Zhoushan, East China's Zhejiang province. [Photo/zj.zjol.com]

Fishermen in Zhoushan, East China's Zhejiang province can now quick freeze fresh shrimp thanks to a liquid-nitrogen instant freezer developed by the Ocean Research Center of Zhoushan at Zhejiang University.

"Sixty-five kilograms worth of selected fresh shrimp can be frozen by the device within 22 minutes," said Dong Wenlai, a local fisherman on Aug 3.

"The device enables shrimp to stay fresh for a long time without affecting their flavor," added Dong.

According to Wang Yueding, president of a local fishing company, fresh shrimp were previously preserved with ice, which was labor-heavy and kept shrimp fresh for only a short time. Even though Freon was used later, it still needed six to eight hours to freeze the shrimp, and allowed a shelf life of just one to two months.

The new instant freezer uses liquid nitrogen at minus 196 degrees as a refrigerant, which can instantly freeze shrimp in a more environmentally friendly way, said Yang Zhijian, director of the marine organism comprehensive use department of the research center.

This is the first time that the device has been used on a fishing vessel.

The frozen shrimp can be sold during any season and exported to overseas countries, with the output expected to increase by 30 percent, said Wang.