The Qualitative And Quantitative Analysis Of Shanxi Mature Vinegar Based On The Near Infrared Spectroscopy

In recent years, because of the increasing potential food safety hazard, food safety hasgradually become a sensitive issue in global public health and international trade. It will be ofgreat significance for the guarantee of food safety and the maintenance of public health toactively do researches on the inspection and control of the harmful food residues. Shanximature vinegar, known as‘the first vinegar in the world’, is rich in amino acids andcarbohydrates. With the advocacy of concept on health in recent years, the consumption ofmature vinegar rises steadily. In order to seek personal interests, some unscrupulous tradersmix up vinegar ages and behave shoddy. Their behaviors have severely intruded on theinterests of consumers, disrupted the vinegar market, and damaged the reputation of Shanximature vinegar.Near Infrared Spectroscopy is a fast, nondestructive, green analysis. It is widely used inthe field of agricultural and food safety, such as the detection of the main component and therecognition of the variety and ages of the liquid. Different vinegar aging decides the internalcomposition and quality of vinegar, and the soluble solids and pH are also quite different. Thispaper adopts the near infrared transmission spectroscopy for the quantitative analysis of theinternal soluble solids content (SSC) and pH levels of Shanxi Vinegar through comparison ofthe effects of different optical paths and spectral pre-processing methods; and for thequalitative analysis of vinegar ages through study of the pros and cons of different maturevinegar ages by different optical paths and spectral pre-processing methods combined withdiscriminant analysis.This paper adopts the near infrared transmission spectroscopy for the quantitativeanalysis of the internal soluble solids content (SSC) and pH levels of Shanxi Mature Vinegarthrough comparison of the effects of different optical paths and spectral pre-processingmethods; and for the qualitative analysis of mature vinegar ages through study of the pros and cons of different mature vinegar ages by different optical paths and spectral pre-processingmethods combined with discriminant analysis. The result shows that the differential treatmentis not suitable for the qualitative and quantitative detection of Shanxi Vinegar, spectralsmoothing in quantitative analysis can effectively improve the spectral signal to noise ratio.The results showed that the best models for SSC were developed by partial least squaresregression(PLSR) together with full wavelength range of raw spectra using 1.0mm opticalpath ,and the Y axis restricted at 1.20 and 15-point smoothing，with correlation coefficient ofcalibration(rcal) was 0.99978, RMSEC was 0.0581, RMSECV was 0.0902; the best modelsfor pH were developed by partial least squares regression(PLSR) together with fullwavelength range of raw spectra using 1.0mm optical path and the Y axis restricted at 1.00,with correlation coefficient of calibration(rcal) was 0.99926, RMSEC was 0.0179, RMSECVwas 0.0302; Qualitative analysis shows that the original spectrum of 1.0mm optical pathtogether with 15-point smoothing and the Y axis restricted at 1.00 of mature vinegarcombined with discriminant analysis can achieve an ideal classification of 1, 3 and 5 yearsShanxi Mature Vinegar, with the correct rate of calibration set classification 98%, predictionset 100%.