摘要
【目的】研究磷钨杂多酸复合酸催化溶浸桑枝异槲皮苷的适宜条件及其酸解作用,为提高桑枝异槲皮苷提取率和桑资源高值利用提供理论依据。【方法】选用磷钨杂多酸与磷酸的复合酸水热反应催化溶浸桑枝异槲皮苷,以异槲皮苷溶浸量为评价指标,采用均匀设计法优化获得复合酸溶浸桑枝异槲皮苷的适宜参数;结合扫描电子显微镜(SEM)和傅里叶变换红外光谱(FTIR)分析桑枝底物形貌及表面官能团变化,解析复合酸催化效应及异槲皮苷溶浸动力学。【结果】投加磷钨杂多酸与磷酸的磷(P)摩尔质量比为0.42∶1的复合酸327.55 mg,于165℃下水热反应100min后,0.5000 g桑枝可溶浸异槲皮苷5.962 mg/g、多糖0.430 g/g,分别是未投加复合酸浸提时的3.17和12.29倍;反应温度和反应时间对异槲皮苷溶浸量影响极显著(P<0.01),复合酸中P摩尔质量比影响次之;FTIR测定图谱中C=C键和C-O键明显减弱,SEM扫描图谱中组织间孔隙变大,出现密集且不规整孔洞,植物组织浊蚀现象明显;异槲皮苷溶浸符合Fick第二定律的一级动力学模型,且溶浸速率常数K随反应温度的升高而增大,在反应温度为165℃时,异槲皮苷最大溶浸量为5.935 mg/g,与试验值相接近。【结论】复合酸溶浸桑枝异槲皮苷方法可行,升高反应温度可提高且加快异槲皮苷溶出,为桑资源高值利用提供新途径。
【Objective】To study the optimum conditions and acidolysis of isoquercitrin from mulberry branches catalyzed by phosphorous tungsten heteropoly acid,which provided a theoretical basis for improving the extraction rate of mulberry isoquercitrin and highvalue utilization of mulberry resources.【Method】A compound acid composed of phosphorous tungsten heteropoly acid and phosphoric acid was used to catalyze the hydrolysis of mulberry branches to extract isoquercitrin under hydrothermal conditions.The amount of isoquercitrin dissolution was used as the evaluation index,and uniform design method was used to optimize the appropriate parameters for isoquercitrin extracted from mulberry branches by compound acid.Combined with Search Engine Marketing(SEM)and Fourier Transform Infra-red(FTIR)characterization to analyze the morphology and surface functional group changes of mulberry substrate,analyze the catalytic effect of compound acid and the kinetics of isoquercitrin leaching.【Result】Adding 327.55 mg compound acid with phosphorus(P)molar ratio of 0.42∶1 in phosphorous tungsten heteropoly acid and phosphoric acid,after hydrothermal reaction at 165℃for 100 min,0.5000 g of mulberry branches could be leached to isoquercitrin 5.962 mg/g and polysaccharide 0.430 g/g,which were as 3.17 and 12.29 times of that without adding compound acid.The effect of reaction temperature and reaction time on isoquercitrin leaching was extremely significant(P<0.01),and the effect of P molar mass ratio in compound acid was the second.FTIR spectrum showed that the C=C bond and C-O bond were wakened.SEM chart showed the tissues became larger,dense and irregular pores appeared,and the turbidity of plant tissues was obvious.Isoquercitrin leaching conformed to the first-order kinetic model of Fick’s second law,and the leaching rate constant K increased with the increase of the reaction temperature,when the reaction temperature was 165℃,the maximum leaching amount of isoquercitrin was 5.935 mg/g,which was close to the experimental value.【Conclusion】The method of compound acid leaching of isoquercitrin from mulberry branch is feasible.Increasing the reaction temperature can increase and accelerate the leaching of isoquercitrin from mulberry branch.which can provide a new way for the high value utilization of mulberry resources.
作者
谭双
王星敏
吴四维
刘小梅
TAN Shuang;WANG Xing-min;WU Si-wei;LIU Xiao-mei(College of Environment and Resources,Chongqing Technology and Business University,Chongqing 400067,China;Chongqing Engineering Research Center for Processing,Storage and Transportation of Characterized Agricultural Products,Chongqing 400067,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2020年第11期2789-2797,共9页
Journal of Southern Agriculture
基金
重庆市科委应用开发重点项目(cstc2017shms-zdyfX0063)。
关键词
桑枝
复合酸
磷钨杂多酸
酸催化
异槲皮苷
mulberry
compound acid
heteropoly acid
acid catalysis
isoquercitrin
作者简介
通讯作者:王星敏(1975-),博士,教授,主要从事农业废弃物处置及资源化利用研究工作,E-mail:wang_chen@tom.com;谭双(1994-),研究方向为农业废弃物处置及资源化利用,E-mail:547150247@qq.com。
