HS-GC-IMS and ATR-FT-MIR Analysis Reveal the Differences in Volatile Compounds, Proteins, and Polyphenols of Royal Jelly

Abstract

Royal jelly (RJ) produced by honeybees (Apis mellifera) is a traditional functional food and usually suffers adverse impacts from heat exposure during collection and transportation. Based on the gas chromatography, the change to volatile compounds in RJ was screened by ion mobility spectrometry. Chemical characteristics were analyzed by infrared spectroscopy combined with a diamond ATR. The results showed that the flavor can be distinguished using HS-GC-IMS based on principal component analysis and 26 compounds, including esters, aldehydes, and ketone, were identified as the differential volatile compounds in RJ. Spectroscopy results suggested that the specific bands were related to the proteins and polyphenols, which were verified by electrophoresis and the Folin–Ciocalteu method. Water-soluble proteins were decreased by 13.11%, and polyphenols contents were decreased by 25.72% compared with the control. Thus, the combination of ATR-FT-MIR and volatile compound analysis can help to identify the quality of RJ quickly and sensitively from the aspect of flavor and chemical characteristics. Our study gives a meaningful suggestion for the analytic strategy of RJ quality.