首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Thermal inactivation of ricin using infant formula as a food matrix
Authors:Jackson Lauren S  Tolleson William H  Chirtel Stuart J
Institution:National Center for Food Safety & Technology, Food and Drug Administration, 6502 South Archer Road, Summit-Argo, Illinois 60501, USA. Lauren.Jackson@fda.hhs.gov
Abstract:Ricin is a potent protein toxin found in the seeds of the castor bean plant, Ricinus communis. Ricin specifically and irreversibly inactivates ribosomes, promoting cell death by inhibiting protein synthesis. It is composed of a ribosome-inactivating enzyme (A-chain) linked to a lectin (B-chain) by a single disulfide bond. Several reports indicate that ricin can be detoxified by thermal treatment; however, the conditions required for inactivation are not well characterized. In addition, little information exists on the thermal stability of ricin added to foods. The objective of this work was to determine the effects of heat treatments on the detection and toxicity of ricin added to milk- and soy-based infant formulas. Reconstituted infant formula powders containing 100 mug of ricin/mL were heated at 60-90 degrees C for up to 5 h. The heat-treated formulas were analyzed by ELISA to determine levels of ricin. The residual cytotoxicity of ricin-containing infant formula after heat treatments was determined using RAW264.7 mouse macrophage cells. The ELISA and the cytotoxicity assay indicated that ricin detection and toxicity decreased with increasing heating times and temperatures. Minimal losses in detection and toxicity were found for ricin heated at 60 degrees C for 2 h. The half-lives of ricin cytoxic activity in a milk-based infant formula at 60, 70, 75, 80, 85, and 90 degrees C were >100, 9.8 +/- 0.5, 5.8 +/- 0.9, 5.1 +/- 0.7, 3.1 +/- 0.4, and 1.8 +/- 0.2 min, respectively; the comparable values for a soy-based infant formula were >100, 16 +/- 1.6, 8.7 +/- 1.2, 6.9 +/- 1.1, 3.0 +/- 0.4, and 2.0 +/- 0.3 min. ELISA detection was a good indicator of the cytotoxicity of heat-treated ricin. The results indicate that ricin is a relatively heat stable protein and may remain toxic under some food processing conditions.
Keywords:
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号