CEBU, Philippines – Scientists today are using genetic engineering to improve the short shelf-life and post-harvest losses of papaya and lessen use of pesticides on eggplants, experts said during a symposium on biotechnology and nutritionally enhanced food crops here.

According to Dr. Evelyn Mae Tecson-Mendoza, research professor of Biochemistry at the Institute of Plant Breeding-University of the Philippines Los Banos (IPB-UPLB), the transgenic papaya or genetically modified papaya by recombinant has now longer shelf-life than the ordinary papaya.

“The papaya usually ripens two days after having a full yellow color and you have to eat it on the second or the third day. Otherwise, it won’t be edible. With this technology, we can delay it from 4 up to 14 days,” elaborated Mendoza.

Delaying the ripening of papaya was made possible through suppressing the production of ethylene. This was done by inhibiting the ACC synthase from synthesizing through the antisense technology, Mendoza said.

Since 1997, Mendoza has been using molecular techniques to solve the problem on post-harvest losses measuring from 30 to 40 percent and the shelf-life of the papaya. But it was only after 10 years that they conducted the first field testing of a homegrown papaya.

Based on the results of the various biochemical testing, Mendoza said the nutritional value of the transgenic papaya is similar to the ordinary papaya noting that both have Vitamin C and antinutrient benzyl isothiocyanate (BITC) contents.

Dr. Frank Shotkoski, director of the Agricultural Biotechnology Support Project II Cornell University, for his part, related that the nutritional values of Bt eggplant and the ordinary eggplant are identical.

Both Shotkoski and Mendoza are optimistic about the eventual transfer of the technology to farmers.

Shotkoski cited that farmers in India have a high demand for the Bt eggplant.

Mendoza disclosed that it will take two years before farmers in the Philippines can use the technology.

“Because this is a technology that involves recombinant DNA technologies and there are biosafety regulations. We need to do field testing under biosafety regulations and we’re also into progression of incorporating the PRSV (papaya ringspot virus) resistance,” explained Mendoza.

Meanwhile, Shotkoski deemed it important to analyze the socio-economic impact and risk assessment of the technology.

“We don’t want to spend an enormous amount of national public money on a project that has very little or no return on investment. If we plan to spend $2 to 3M on a project and it won’t have any benefit to the consumer or the farmer, then the technology won’t be adapted. We use this as a guide to assess the probability or the likelihood whether the technology would be adapted,” said Shotkoski.