Discrimination of the Red Jujube Varieties Using a Portable NIR Spectrometer and Fuzzy Improved Linear Discriminant Analysis.

Zuxuan Qi,Yangjian Yang,Xiaohong Wu,Haijun Fu,Bin Wu

doi:10.3390/foods11050763

Abstract

In order to quickly, nondestructively, and effectively distinguish red jujube varieties, based on the combination of fuzzy theory and improved LDA (iLDA), fuzzy improved linear discriminant analysis (FiLDA) algorithm was proposed to classify near-infrared reflectance (NIR) spectra of red jujube samples. FiLDA shows performs better than iLDA in dealing with NIR spectra containing noise. Firstly, the portable NIR spectrometer was employed to gather the NIR spectra of five kinds of red jujube, and the initial NIR spectra were pretreated by standard normal variate transformation (SNV), multiplicative scatter correction (MSC), Savitzky-Golay smoothing (S-G smoothing), mean centering (MC) and Savitzky-Golay filter (S-G filter). Secondly, the high-dimensional spectra were processed for dimension reduction by principal component analysis (PCA). Then, linear discriminant analysis (LDA), iLDA and FiLDA were applied to extract features from the NIR spectra, respectively. Finally, K nearest neighbor (KNN) served as a classifier for the classification of red jujube samples. The highest classification accuracy of this identification system for red jujube, by using FiLDA and KNN, was 94.4%. These results indicated that FiLDA combined with NIR spectroscopy was an available method for identifying the red jujube varieties and this method has wide application prospects.

Highlights

Red jujube is a kind of agricultural product with a long history
The pre-processing method and feature extraction algorithm were S-G filter and fuzzy improved linear discriminant analysis (FiLDA), respectively, and the classification accuracy of the K nearest neighbor (KNN) reached 94.4%
To classify red jujube varieties quickly, nondestructively, and effectively, FiLDA algorithm coupled with near-infrared reflectance (NIR) spectroscopy was proposed in this study

Summary

Introduction

Red jujube is a kind of agricultural product with a long history. It has caught the fascination of people all over the world and is widely planted in China. The current testing methods for red jujube varieties at the markets are too complicated and are unsuitable for large-scale application. These methods are not friendly to consumers, so it is very necessary to build a fast, concise, cheap, and reliable method that can recognize the red jujube varieties

Methods

Results

Discussion

Conclusion