Safety assessment of genetically engineered potatoes with designed soybeanglycinin: compositional analyses of the potato tubers and digestibility ofthe newly expressed protein in transgenic potatoes

The compositions of transgenic potatoes with intact and modified genes for soybean glycinin were compared with those of control potatoes; non-transgen ic or transgenic ones with at vector. The expression levels of glycinin pro teins in the transgenic potato tubers were approximately 12-31 mg g(-1)-tot al soluble protein. With reference to six major components, moisture, prote in, lipid, fiber, ash and carbohydrate, there were no significant differenc es between transgenic and control potatoes. The levels of glycoalkaloids in transgenic potato tubers, as well as in transgenic controls, increased in comparison with those in non-transgenic ones, though the level was within t he permitted limit. The modified glycinin expressed in the transgenic potat o tuber was digested under the simulated gastric conditions. From these res ults, the transgenic potatoes with intact and modified glycinin genes are c onsidered to be as safety utilization for food as non-transgenic potatoes. (C) 1999 Society of Chemical Industry.