Identification of changes in volatile organic compounds in Ophiopogonis Radix containing spoiled products in different proportions by headspace-gas chromatography-ion mobility spectrometry

Abstract

Ophiopogonis Radix is a kind of traditional Chinese medicine as well as a type of functional food. Because Ophiopogonis Radix grows in the ground, it is often damaged by worms during planting or broken when people try to dig them out, which leads to the containments of spoiled products of different proportion in Ophiopogonis Radix. Volatile organic compounds (VOCs) in Ophiopogonis Radix, which involves spoiled products in different proportions, were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Finally, a total of 87 VOCs were discovered after analysis, and 14 of them were chose to established characteristic fingerprints. Twelve of the 14 characteristic compounds were be recognized by a built-in database. The results showed that the content of hexanol, ethanol, methanol, (E)-2-hexenal, and hexanal was in inverse proportion with the containing of spoiled products, so they may be characteristic VOCs of fresh Ophiopogonis Radix,; and the content of 3-methy-1-butanol, furfural, 5-methylfural, phenylacetaldehyde, 2-methylbutanoic acid, 2-butanone, and 2-acetylfuran are proportional to the containing of spoiled products, so they may be the characteristic of VOCs of spoiled Ophiopogonis Radix. The signal peak intensities of the 14 characteristic VOCs were used as the variables of principal component analysis (PCA). The result shows that the fresh Ophiopogonis Radix and the spoiled Ophiopogonis Radix could be clearly differentiated, and the different proportions of spoiled products were grouped into separate categories, respectively. The larger the proportion of spoiled products, the greater the difference between the sample and fresh Ophiopogonis Radix. PRACTICAL APPLICATIONS: Ophiopogonis Radix is a kind of commonly used traditional Chinese medicine and functional food. In the actual use of Ophiopogonis Radix, the damage caused by worms during planting and the breakage during being dug out often lead to Ophiopogonis Radix containing spoiled products in the market. The existence of spoiled products greatly affects the quality and safety of Ophiopogonis Radix. Due to the difference in flavor between fresh Ophiopogonis Radix and spoiled products, the present study used HS-GC-IMS method to analyze the VOCs in fresh Ophiopogonis Radix and Ophiopogonis Radix containing spoiled products of different proportions and screened out the characteristic VOCs of fresh Ophiopogonis Radix and spoiled Ophiopogonis Radix. The results provide scientific basis for quality control of Ophiopogonis Radix.

Keywords: GC-IMS; Ophiopogonis Radix; spoiled products; volatile compounds; volatile organic compounds.