Development And Application Of A Fluorescence Spectroscopy-based Chinese Baijiu Detector

In recent years,the increasing market demand for Chinese Baijiu has led to rapid development in the whole industry.The medium-to-high end product-“Aged Baijiu”-is now experiencing tremendous growth as the most popular Baijiu type.However,the rapid development also brought a lot of problems like incorrect year labels or insufficient dosage of high age base wine.Given these problems,current testing methods for Aged Baijiu can hardly meet the requirement,especially when dealing with base wine type.Most testing methods in the market require expensive instruments and professional operating personnel,which makes them hard to be widely adopted.Based on fluorescence spectroscopy of Baijiu,a conductive method is devised to test both the age and the amount of base wine in the Aged Baijiu in this paper.A miniaturized,cost-effective,accurate and user-friendly Baijiu tester has also been invented.The Baijiu tester,combined with the aged Baijiu testing technique,now composed a dedicated Baijiu testing instrument that can fulfill the market requirement.This paper will introduce the following three main research steps:1.Thirty three-dimensional fluorescence spectra of different Baijiu were measured using an experimental-grade spectrometer,depending on their aroma type,brand,and productive year.By comparing those three-dimensional fluorescence spectra,the fluorescent substances were determined to be the key element of the spectra formulation of Aged Baijiu.Based on that,the researcher measured the fluorescence spectra of common organic substances in several types of Baijiu and correlated the spectra of organic substances with those of Baijiu to clarify the sources of spectral variability in Baijiu of different aromas,brands,and vintages.2.Measure the three-dimensional fluorescence spectra of Aged Baijiu and compare them with the base wine spectra.With similarity between Aged Baijiu‘s 3D fluorescence spectra and the base wine’s,the final testing method for age detection is proposed.Given the spectral differences between the base wines of Baijiu,the 3D fluorescence spectra of aged Baijiu were decomposed using a parallel factor algorithm,and the source of spectral variability is the content of fluorescent substances in the Baijiu.A linear regression model of the fluorescence of a substance or substances in the aged Baijiu and the base wine is developed to detect at least one base wine volume fraction.To study the spectral similarity as a whole,researcher combined the spectral similarity between Aged Baijiu and base wine.A prediction model of similarity and Baijiu age was then established.The results of this experiment shows that the age detection error is less then 1 year and the volume fraction error of high age base wines does not exceed 2%.While the age detection algorithm proposed in this paper implements age detection of aged Baijiu along with the amount of base wine used in aged Baijiu,it provides ideas and references for future study of aged Baijiu and similar multi-component complex mixing systems.3.A miniaturised Baijiu detector has been developed for 3D fluorescence spectral acquisition of Baijiu.The optical path,device selection and software development are designed based on the fluorescence properties of Baijiu.One of the excitation and emission units was calibrated to ensure the accuracy of the measurement data.The linear fitting equation between fluorescence intensity and quinine sulphate concentration has a coefficient of determination as high as 0.999,demonstrating the accuracy and stability of the white wine detector through concentration calibration experiments with quinine sulphate.The actual application of the Baijiu detector was used to carry out age testing of aged Baijiu.Taking a certain brand of Baijiu as experimental subject,with the developed Baijiu detection algorithm and cross-validation method,a 3D fluorescence spectrum was formulated and measured to predict the age of this brand of aged Baijiu.The aim of high accuracy on age detection within short measurement time was achieved,and the age detection error is less than 1 year.The development of the age detection algorithm for aged Baijiu provides an idea and method for the detection of Chinese Baijiu,and posts positive effects on regulating the aged Baijiu market.The successful application of the Baijiu detector can improve the large expense and size of traditional commercial spectrometers and help to promote the Baijiu-specific instruments.