JINAN - Jin Cong busies himself inspecting the spring plantation of edamame. He needs to make sure that the vegetables meet the export quality when they are ready to be shipped in a few months.

Jin is the general manager of Jining Sunshine Agricultural Technology Co Ltd, a leading producer of frozen vegetables in Jining, East China's Shandong province.

"Green soybeans (edamame) mostly go with Japanese sakes, which are quite popular in izakayas (a type of Japanese pub)," Jin said. He expects the company's edamame exports to Japan to grow by one-third this year.

Founded in 2011, the company is among the top 10 frozen veggie exporters in the country. It exports about 4,500 kg of frozen green soybeans to both Kansai and Kanto regions of Japan annually. It also exports broccoli and shepherd's purses.

To better meet demands of Japanese customers, Jin said that the company had sent staff to attend the 44th International Food and Beverage Exhibition, held in Tokyo from Tuesday to Friday.

The firm owns more than 333 hectares of edamame fields in Jiaxiang county. They are grown in April and harvested in July.

Jin said his products need to pass 201 pesticide residue tests and five microbiological detections before they reach customers.

Exporters like Jin's firm have stuck to stringent quality standards in the last few years.

Zhang Deyan, vice general manager of the Qingdao-based Fusheng Foods Co., Ltd, said the company had strengthened quality control in its 20 spinach planting bases by monitoring air, soil and water conditions.

Farm chemicals have been carefully used and strictly controlled to meet the standard of minimal pesticide residues.

"We have set up three detection procedures to perform more than 260 tests, covering the whole process from growing, harvest to production," Zhang said. The company has invested 20 million yuan (about $3 million) to build new testing labs.

The company expects an estimated 10 percent growth in frozen vegetable exports to Japan this year.

Figures released by the Qingdao Customs show that 227,000 tonnes of frozen vegetables were exported to Japan from Shandong in 2018, up 7.9 percent year on year, accounting for more than one-fifth of Japan's annual import of 1.06 million tonnes.

Qingdao Customs has launched special campaigns to improve the quality and safety of exported vegetables by promoting enterprise upgrading, deep processing of primary agricultural products, and establishing model areas for quality control.