便携式光谱分析仪对叶菜失水程度的无损检测研究

Study on Nondestructive Testing of Water Loss Degree of Leafy Vegetables by a Portable Spectrometer

利用自行研发的线性可调谐滤光片(LVF)便携式光谱仪对蔬菜失水程度进行了无损检测研究。通过获取小白菜、菠菜、叶菜生菜、油菜4种叶菜蔬菜叶片,分别在失水0 h、失水12 h、失水24 h、失水48 h的平均光谱曲线图进行对比分析。结果表明:蔬菜在失水过程中,便携式LVF光谱仪能有效快速反映其内部叶绿素的变化,并通过4种蔬菜叶片在同一个失水时间段下的光谱反射率曲线对比分析,表明利用便携LVF光谱仪可快速、无损的对叶菜类蔬菜失水程度的判别进行定性区分。与此同时,根据叶菜蔬菜叶片的光谱曲线构建蔬菜叶片叶绿素SPAD含量平均值综合预测模型,结果显示,叶菜类蔬菜叶片的平均光谱值在新鲜状态下的SPAD值建模相关系数为0.73,表明利用自行研发的便携式LVF光谱仪对叶菜类蔬菜叶片失水程度进行定量分析是可行的。

The non-destructive testing in the process of the vegetable water loss by the self-developed linear tunable filter（ LVF） was preliminary explored. A comparative analysis was conducted for mean spectrum curve respectively for four kinds of leafy vegetable,leaves of pakchoi,spinach,leafy vegetable lettuce and oilseed rape at 0,12,24 and 48 h of water loss. It was found that in the water loss process,portable spectrometer,LVF could effectively,rapidly reflect changes of their internal chlorophyll. Additionally,it was found from the comparative analysis on spectral reflectivity cure of four kinds of vegetable leaves at the same water loss period that it was feasible to rapidly and nondestructively conduct qualitative distinction of water loss degree of leafy vegetables by use of portable LVF spectrometer. At the same time,a comprehensive prediction model of mean chlorophyll SPAD content in vegetable leaves was established in terms of spectrum curve of leafy vegetable leaves,and it was found that correlation coefficient R for SPAD value model in terms of mean spectral value of leafy vegetable leaves in fresh status equaled to 0. 73,suggesting that it was feasible to conduct a quantitative analysis for water loss degree of leafy vegetable leaves by use of the self-developed portable LVF spectrometer.