摘要
鉴于黄曲霉毒素G1(AFG_(1))的毒性强,难降解和有效去除,利用AFG_(1)与DNA的嵌插结合,构建选择性吸附消除AFG_(1)的有效方法。AFG_(1)嵌入DNA的最佳反应条件为pH 7.4及30℃,其DNA结合饱和值和去除率为1.66、88.14%。添加NaCl、CaCl_(2)、L-天冬氨酸、葡萄糖、尿素、亮氨酸、赖氨酸、维生素C等后,DNA结合饱和值分别为1.45、1.45、1.29、1.05、1.95、1.95、2.32和2.90。去除率分别为78.08%、76.44%、75.92%、75.16%、88.41%、88.67%、88.87%、90.27%。NaCl、CaCl_(2)、L-天冬氨酸、葡萄糖等负电基团或者离子强度较高不利于AFG_(1)-DNA嵌插结合,而尿素、亮氨酸、赖氨酸、维生素C等带正电基团和相似基团的物质利于AFG_(1)-DNA的嵌插结合。花生油中的AFG_(1)的去除率达到80%以上。动力学相关系数和吸附容量可知,该吸附过程符合准二级动力学模型,表明吸附过程的限速步骤为化学相互作用。吸附过程遵循Freundlich等温吸附模型,该吸附过程为多层吸附。热力学结果显示DNA对AFG_(1)的吸附是自发的放热过程。综上,DNA能选择性吸附AFG_(1),因此,可进一步开发DNA新型材料,在去除食品中黄曲霉毒素方面有重要意义。
In view of the high toxicity of aflatoxin G1(AFG_(1))and the difficulty in decomposing and effectively removing it,an effective method for selective adsorption and elimination of AFG_(1)was established via intercalation of AFG_(1)and DNA.The optimum reaction conditions for intercalating AFG_(1)into DNA molecules were pH 7.4 and 30,and the DNA℃binding saturation value and removal rate were 1.66 and 88.14%.After the addition of sodium chloride,calcium chloride,L-aspartic acid,glucose,urea,leucine,lysine or vitamin C,the DNA binding saturation values were 1.45,1.45,1.29,1.05,1.95,1.95,2.32 and 2.90 respectively,with the removal rates being 78.08%,76.44%,75.92%,75.16%,88.41%,88.67%,88.87%and 90.27%respectively.A negatively charged group(such as sodium chloride,calcium chloride,L-aspartic acid and glucose),or a relatively high ionic strength,was not conducive to the intercalation of AFG_(1)and DNA,whilst substances carrying positively charged groups and similar groups(such as urea,leucine,lysine,and vitamin C)were conducive to the AFG_(1)-DNA intercalation.The removal rate of AFG_(1)in peanut oil reached over 80%.The kinetic correlation coefficient and adsorption capacity showed that the adsorption process conformed to the pseudo-second-order order model,indicating that the rate-limiting step of the adsorption process was chemical interaction.The adsorption process followed the Freundlich isotherm adsorption model,thus the adsorption process was multilayer adsorption.Thermodynamic results showed that the adsorption of AFG_(1)by DNA was a spontaneous exothermic process.In conclusion,DNA can selectively adsorb AFG_(1).Therefore,new DNA materials can be further developed,which is of great significance in the removal of aflatoxin in food.
作者
马琼
李军生
黄国霞
阎柳娟
马纪
MA Qiong;LI Junsheng;HUANG Guoxia;YAN Liujuan;MA Ji(College of Biological and Chemical Engineering,Guangxi University of Science and Technology,Liuzhou 545006,China)
出处
《现代食品科技》
CAS
北大核心
2022年第10期272-282,共11页
Modern Food Science and Technology
基金
国家自然科学基金项目(21966008)
广西自然科学基金项目(2018GXNSFDA281030)
广西自然科学基金项目(2020GXNSFAA159021)。
