Safety evaluation of soybean protein isolate oxidized by a hydroxyl radical-generating system

The oxidative modification of soybean protein isolate (SPI) induced by a hydroxyl radical-generating system (HRGS) has a broad range of applications. However, few toxicology studies exist on this material. The safety of HRGS-oxidized SPI was assessed using subchronic and genotoxicity studies. A 30-day subchronic study (250, 500 and 1000 mg/kg center dot BW) in rats showed no significant adverse effects on food consumption, body weight (BW), mortality, hematology, biochemistry, necropsy, organ weight or histopathology. The result of an Ames test showed that HRGS-oxidized SPI was not mutagenic to the test strains. The results of a bone marrow micronucleus test and mouse sperm abnormality test showed HRGS-oxidized SPI (417.5, 835.0 and 1670.0 mg/kg center dot BW) did not produce any aberrant effects on bone marrow cells or mouse sperm. Therefore, HRGS-oxidized SPI showed no genotoxicity in vivo or in vitro. In conclusion, these results support the safe use of HRGS-oxidized SPI as a food and dietary supplement. (C) 2017 Elsevier Ltd. All rights reserved.