摘要
保鲜膜能提高果蔬保水性,隔绝外界细菌侵染,延长货架期。为了准确估测覆盖保鲜膜果蔬品质的优劣,对其货架期进行预测具有重要意义。应用高光谱技术结合化学计量学方法对同等贮藏条件下覆膜新鲜菠菜叶片的货架期进行了预测。先采集五个不同贮藏时间下75盘共300片菠菜样本在可见-近红外(VisNIR,380~1 030nm)与近红外(NIR,874~1 734nm)波段的高光谱数据,然后测定不同贮藏时间下菠菜叶片叶绿素含量。提取300片覆膜菠菜叶片的平均光谱(200个为建模集,100个为预测集)后,对建模集光谱进行主成分分析(principal component analysis,PCA),发现不同贮藏期内叶片光谱数据在前3个主成分空间有一定的聚类。根据建模集光谱信息与预先赋予的不同贮藏期虚拟等级分别建立偏最小二乘判别分析(partial least squares discriminant analysis,PLS-DA)模型,得到预测集样本的贮藏期总的判别准确率分别为83%(Vis-NIR)和81%(NIR)。表明,高光谱技术结合化学计量学方法能够实现对新鲜菠菜货架期的分类和预测,为消费者正确评价覆盖保鲜膜的菠菜品质提供了理论指导,也为后期果蔬货架期检测仪器的开发提供了技术支持。
In order to prolong the shelf-life of fruits and vegetables,plastic films have been covered on them to improve water retention and keep external bacteria away.It is of great significance to estimate the quality of packaged fruits and vegetables accurately by predicting the shelf-life of them.In this research,hyperspectral technology combined with chemometric methods were employed to estimate the shelf-life of fresh spinach leaves in the same environment.Hyperspectral data covering the range of VisNIR（380-1 030nm）and NIR（874-1 734nm）were acquired from 300 spinach leaves（75dishs）which were stored in 4 ℃among 5periods（0d,2d,4d,6d,8d）.Meanwhile,the chlorophyll contents of all spinach leaves were determined.The mean spectra of 300 spinach leaves（200leaves in training set and 100 leaves in prediction set）were extracted.And then,principal component analysis（PCA）on the training set of 200 spectra from 5periods of shelf-life displayed apparent cluster.Partial least-squares discriminant analysis（PLS-DA）models were established according to spectral datas and the virtual levels that we ascribed to the different storage periods previously.The total discriminant accuracy rates of prediction set were 83%（VIS-NIR）and 81%（NIR）,respectively.The result indicated that the classification and prediction on the shelf-life of fresh spinach can be realized with hyperspectral technology combined with chemometric methods,which offered a theoretical guidance to evaluate the quality of packaged spinach for consumers,and provided technical supports for the development of instruments used for testing the shelf-life of fruits and vegetables in further study.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2017年第2期423-428,共6页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(61273062)
国家高科技研究发展计划"863"项目(2013AA102301)资助
关键词
高光谱技术
菠菜叶片
化学计量学方法
货架期
Hyperspectral technique
Spinach leaves
Chemometrics methods
Shelf-life
