Discrimination of polysaccharides from Angelica sinensis and its different processed products based on Fourier transform infrared spectroscopy

Abstract

A new rapid and nondestructive method for identifying polysaccharides from Angelica sinensis and its different processed products was developed, and this method was based on Fourier transform infrared spectroscopy (FTIR). In the clinic of traditional Chinese medicine, unprocessed Angelica sinensis(UAS) is of ten used after processed, the common processed products are Angelica sinensis parched with wine(WAS), Angelica sinensis parched with soil(SAS), Angelica sinensis parched with oil(OAS) and Charred Angelica sinensis(CAS). In order to use polysaccharides from Angelica sinensis and its processed products effectively and reasonably in clinic, it is very necessary to identify them. FTIR of polysaccharides from Angelica sinensis and its different processed products was determined, and then it was decomposed by discrete wavelet transform (DWT). The high frequency information in scale 2, 3 and 4 was selected as feature information, from which the each wavelet entropy was extracted as characteristic value. BP neural network was trained with these characteristic values. The trained BP neural network was used to identify polysaccharides from Angelica sinensis and its different processed products. According to 30 prediction samples, the correct rate for recognition was 93. 3%, which indicates that: it has better feasibility to identify polysaccharides from Angelica sinensis and its different processed products by this method, which is based on FTIR, discrete wavelet transform and BP neural network