基于激光光致发光光谱的果实成熟度测试方法研究  

Measurement of Fruit Maturity Based on Laser-Induced Photoluminescence Spectrum

作　　者：王乐妍[1] 张冬仙[1] 章海军[1] 王晓萍[1] 

机构地区：[1]浙江大学现代光学仪器国家重点实验室,浙江杭州310027

出　　处：《光谱学与光谱分析》2008年第12期2772-2776,共5页Spectroscopy and Spectral Analysis

基　　金：国家"863"计划项目(2006AA06Z406)资助

摘　　要：介绍了一种探测果实成熟度的新方法。采用红光半导体激光器(655 nm)对果实样品进行照射,所得激光光致发光光谱在685 nm附近产生明显峰值。通过传统的糖度含量检测法测定样品的糖度含量,得到果实的激光光致发光光谱峰值强度随糖度含量增加而降低。利用最小二乘法原理对光致发光强度与糖度含量值进行比较分析,建立了两者的拟合曲线。以红心李和桃子为例,两者之间的相关系数分别为98.92%与97.31%。设计针对该激光光致发光光谱检测系统的分析软件,实现了生成标准成熟光谱及检测未知成熟度的果实光致发光光谱两部分功能,通过比较可以自动得出果实成熟度等级的判定。结果证明,激光光致发光光谱的成熟度检测方法具有非破坏性、设备小型化、低能耗的优点,在果实成熟度的实时快速检测方面具有应用价值。Grounding on the concepts of biophotonics measurement,the authors first used a red semiconductor laser（655 nm） to irradiate fruits.Compared with other kinds of illuminating sources,the red semiconductor laser is less expensive and takes little space.The laser-induced photoluminescence spectrums could be detected by coupling fibre-optics probe when the fruits are illuminated by laser.And the spectrum has a distinct peak of relative intensity around the 685 nm wavelength that varies with the degree of fruit maturity.Sugar content measurement was used to prove the laser-induced photoluminescence measurement.The authors tested the sugar content of the fruit specimens,and found that the relative peak value of the fruits＇ laser-induced photoluminescence spectrum decreases with the increase in their sugar content.The authors used partial least-squares（PLS） regression to perform an analysis of the relationship between the laser-induced photoluminescence intensity and the sugar content,fitting a curve of the two parameters.The correlation coefficient r of the fitted value and the actual value is 98.92% for red-inside plum and 97.31% for nectarine.So the authors could generalize that there is an approximate linear relationship between the peak value of laser-induced photoluminescence intensity and the sugar content of fruits,and we could use the maturity measurement based on this concept to decide the fruit ripeness.The authors designed the analytic program for this laser-induced photoluminescence spectrum measurement system,which mainly realizes two functions： generating the standard ripe spectrum of a certain kind of fruit from a quantity of their spectra,and,according to this standard spectrum,determining the maturity degree of an unknown spectrum,and at the same time,displaying the unknown laser-induced photoluminescence spectrum.Incorporating this analytic program with the optical spectrometer,it becomes conceivable to test the fruit maturity very conveniently and quickly.The measurement system of fruit ma

关 键 词：激光光致发光 果实成熟度 糖度含量检测 最小二乘法 光谱分析 

分 类 号：TG115.3[金属学及工艺—物理冶金]