Study On Illegal Cooking Oil Based On The Echnologies Of Three-dimensional Luorescence Spectrum And Dynamic Light Cattering

Edible oils act as consumer goods that are essential to the people’s daily life. Oilsare the important food which are used to store heat for human body, provide fatty acidsand promote the absorption of fat-soluble vitamin, and oils can prevent mechanicaldamage to the human body; Also, as the material of cells’ surface, oils are has closerelation with the recognition and immunization of cells. However, due to the inadequatesupervision on food production, the drawback of management and laws, and theunderdeveloped technology of development and utilization, illegal cooking oil is used toproduce edible oil by unscrupulous producers and served on the table again. Moreover,illegal cooking oil contains a large number of harmful substances, and long-term intakeof illegal cooking oil will cause serious damage to the body, even lead to cancer, andlife threatening. Thus, it has important realistic significance to seek proper methods thatcan detect illegal cooking oil quickly and efficiently. In this paper, it is studied byfluorescence spectroscopy technology combined with the technique of dynamic lightscattering to characterize the optical properties of illegal cooking oil.In this paper, three-dimensional fluorescence spectrum technology was applied todetect the edible oil commonly used (peanut oil, soybean oil) and the sampling of illegalcooking oil. It is found that there are many differences in the spectra that characterizethe fluorescence peaks and fluorescence intensity of oils. What is more, it is presentedthat there appear much more fluorescence peaks in the spectra of illegal cooking oilsthan edible oils. That is to say, the fluorescence performance of illegal cooking oil ismore complicated, and they are quite different in fluorescence intensity. The resultsconfirm that different fluorescence characteristics of edible and illegal cooking oils areresulted of different internal structures. Then, the temperature impacts on oils areanalyzed and it’s demonstrated that high temperature will accelerate the oxidation ofoils. The experimental results indicate that three-dimensional fluorescence spectrumtechnology to detect oils has lots of advantages such as simple operation, less dosage,intuitive and clear results and so on.In this paper, dynamic light scattering technique is used to detect oils andcharacterize comprehensively the oils’ optical properties. After the experiments on oils,it is found that there are many differences between edible oils and cooking oils indynamic optical properties. Furthermore, it is mainly explained through4main points: the autocorrelation curve, the CONTIN algorithm curve, the average particle sizedistribution and photon counting rate. Finally, the results show that the autocorrelationcurves of edible-oil samplings are relatively smooth and they have fewerdisturbance.On the contrary, autocorrelation curves of illegal-cooking-oil samplingsdecay fast and have much more disturbance and the distributions of the CONTINalgorithm curves represent illegal-cooking-oil samplings are more concentrated.Meanwhile, the mean particle size of illegal-cooking–oil samplings is far less than theedible oils’, but photon counting rate is larger than the edible oils’. In addition, since thetemperature has a great impact on the particle’s movement; the light scatteringproperties of the particles under different temperatures are analyzed in details. By alarge number of experiments, it is evident that dynamic light scattering technique can beapplied to detect oils, accompanied with good effect and high precision.By comparing the results of fluorescence spectrum experiments and dynamic lightscattering experiments, it’s found that the Rayleigh scattering light intensity of illegalcooking oils samplings is significantly greater than edible oils samplings’. Furthermore,the Rayleigh scattering light intensity of soybean oil samplings after heated is greaterthan it before heat treatment. The results of two kinds of experiments are matched. Inthis paper, it is forcefully proved that the fluorescence spectrum and dynamic lightscattering techniques are feasible in the detection of illegal cooking oils.