Study On The Fluorescent Spectra Of Ponceau 4R And Amaranth Two Pigments Used Frequently In Food

Food safety is now the most important problem and it is urgent to detect food safety for packinghouse in china.So In order to offer support in technology ,we should strengthen the study on detecting technology of food safety.Although the system of detecting food safety has been built,the demand on precision and sensitive is getting more and more high in modern times . And the existing detecting technology can not satisfy the people's needs,so we should explore fast and advanced detecting technology on food safety and put it into practice of the process of producing. Base on the concerned , this paper carried on the discussion on the fluorescence characteristic of two pigments in the food additives using fluorescence Spectrum Detection,ponceau 4R and amaranth , and given out proper explanation about mechanism.Using two order differential coefficient to fluorescent spectra and matrix , fluorescent spectra of the two pigments have been studied and calculated .The fluorescence spectra of ponceau 4R induced by 220-400nm light were studied in the present paper.The result show that ponceau 4R has four obviously fluorescent spectra peaks which respectively located at 420nm,530nm,635nm and 637nm, each of these fluorescent spectra peaks has different best induced light .We also made some research on the fluorescence spectra of amaranth,which is isomeric object of ponceau 4R .Excited by proper light , amaranth also has obviously fluorescent spectra. Amaranth has the largest fluorescent intensity excited by 360nm light ,and the fluorescence peak always located about 635nm .Based on Beer-Lambert theory ,the relationship between fluorescent intensity and excited light was calculated .The result shows the fluorescent intensity gauss relationship with excited light.By this result,the experiment data have been fitted by gauss function .In order to further study amaranth's characteristic,the two order differential coefficient to fluorescent spectra excited 360nm light was analyzed, which have four minimum points.Based on spectrum analysis theory,the minimum point of two order differential coefficient to fluorescent spectra is corresponding to fluorescent cluster's fluorescent peak.For it has four minimum points,the amaranth perhaps has four different fluorescent clusters. The four different fluorescent clusters are interactional each other resulted in amaranth has only one obvious fluorescent peak.It is consider that the ponceau-4R has four obvious fluorescence peaks because it has four fluorescent clusters.As it's isomeric object, amaranth has the same molecular formula .So amaranth should has four fluorescent clusters as ponceau-4R.In order to find the different sensitivity of every fluorescent clusters when they were been excited by different light, and find the relation between the two pigments, the intensity of every fluorescent spectra peaks were calculated by matrix operation based on the principle of additive property of fluorescent intensity. One can conclude that the fluorescent spectra peak of amaranth is homologous to the third fluorescent spectra peak located on 635nm of ponceau 4R. Based on this character ,the influence of four fluorescent clusters on two pigments's fluorescent spectra were discussed . This paper also attempts to find the origin of their different fluorescence spectra from the difference in the structure.The two pigments have several kinds of functional groups.In order to study every group's characteristic some simple substances whose molecular has only one kinds of the group similar with one kind of the groups.The research results will contribute to further study and use safely about pigments ,offer effective experiment data,and supply a gap on fluorescent spectra analysis of synthesize pigments in food.It will inevitably promote the course to apply the way with fluorescent spectra analysis to food safely detect as soon as possible.