导读：采集方式获得近红外光谱，来预测蜂蜜中结构和含量都很相近的果糖和葡萄糖含量。结果发现，两种测量方式下果糖、葡萄糖的预测准确度存在着较大的差异。

Difference Analysis and Optimization Study for Determination of Fructose and Glucose by Near Infrared Spectroscopy

TU Zhen-Hua1 ,ZHU Da-Zhou2 ,JI Bao-Ping1 ,MENG Chao-Ying3 ,WANG Lin-Ge1 ,QING Zhao-Shen* 1

 1 (College of Food Science and Nutritional Engineering,China Agricultural University,Beijing 100083)

2 (National Engineering Research Center for Information Technology in Agriculture,Beijing 100097)

3 (College of Information and Electrical Engineering,China Agricultural University,Beijing 100083)

Abstract :A total of 101 honey samples that originated from 20 different unifloral honey and other multifloral honey samples were collected from China. FT-NIR spectrometer were applied to determinate the content of fructose and glucose of honey with two different modes: transflectance (800 - 2500 nm,2 mm optical path length)and transmittance(800-1370nm,20mm optical path length). It was found that the prediction accuracy of fructose and glucose had significant difference with the two modes. In order to analyze the reason of this difference,support vector machine (SVM) was used to analyze the non-linear information,and genetic algorithm (GA) was used to analyze the characteristic wavelengths. The result indicated that the detection difference of fructose and glucose was originated from their different characteristic wavelengths. Through the optimization of detection method,it was found that for the determination of glucose,short wavelength and long optical path length should be used,on the other side,the whole wavelength region and short wavelength,with selecting the characteristic wavelength to avoid the disturb of water can also be used. For the determination of fructose,whole wavelength region and short optical path length should be used. Linear regression methods such as PLSR could obtain good results,and non-linear methods such as SVM did not improve the model performance.

Keywords: Honey; Near infrared spectrometry; Fructose; Glucose; Characteristic wavelengths