SEIKA, Kyoto Prefecture--Vegetables grown in a factory with no pesticide chemicals might be safer to eat than field-grown vegetables, but consumers are still reluctant to bite.

Now Kyoto Prefectural University has a nutritious sales pitch it hopes will make them more appetizing.

It says it has developed the technology at its campus here in Kansai Science City (Keihanna) to significantly enhance antioxidant properties and minerals in vegetables grown indoors.

“Keihanna veggies have improved in flavor and texture,” said Go Takeba, former president of the university and professor emeritus of vegetable physiology, referring to the plants raised using the new technology. “We are hoping that the technology will attract widespread attention and become popular.”

Some producers are planning to introduce the technology, according to the university.

Its new science is being developed in a project that started at the Seika campus in fiscal 2012 called “next-generation plant factory research.”

The vegetables raised are called Kenko Yasai Keihanna (healthy vegetables Keihanna), and the project is supported by the Kyoto prefectural government.

In addition to being free of chemicals, produce grown in factories boasts a stable supply as harvests are not subject to fluctuations in the weather.

But factory vegetables have not taken off despite the advantages.

“Factory vegetables are less attractive in terms of quality than outdoor vegetables, and the two have yet to be differentiated successfully,” said Takeba.

The technology to bolster the favorable properties of factory vegetables followed a series of experiments on photosynthesis and the ability to absorb nutrients. The experiments were also conducted based on requests from experts on preventive medicine.

The university discovered that combining blue light-emitting diodes with culture fluid that does not contain nitrogen considerably improves the nutritious features of factory vegetables.

The amount of vitamin C and other antioxidant properties increased to 10 to 50 times more than in field vegetables, according to Takeba.

Other data showed there was also four to 12 times more iron, while manganese, which activates enzymes, was increased by 1.6 to 14 times.

Residue nitrate concentration was reduced to one-sixth to one-10th that of conventional factory vegetables. A lower concentration number is better.

Lettuces, bok choy and Japanese mustard spinach have been raised with the technology. Researchers are now eyeing root vegetables for future production.