Effects of Different Drying Methods on Volatile Flavor Components of Daylily Powder Analyzed by Gas Chromatography-Mass Spectrometry Combined with Electronic Nose

In order to clarify the effect of drying methods on the volatile composition of daylily powder, an electronic nose system and headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) were used to analyze the volatile components of daylily subjected to natural drying, hot air drying, vacuum freeze drying or spray drying. Principal component analysis (PCA) was performed on the volatile composition data of the four dried samples. The results showed that a total of 68 volatile substances were detected in these samples, including 41 in the natural dried sample, 41 in the hot air dried sample, 35 in the vacuum freeze dried sample, and 26 in the spray dried sample. Among them, the vacuum freeze-drying sample had the highest content of total volatile components of 56.36 μg/g. PCA and linear discriminant analysis (LDA) clearly distinguished the different drying methods. In conclusion, hot air drying retains the volatile flavor compounds of daylily and thus imparts a better flavor. Our findings can provide a theoretical basis for the utilization of daylily powder in the future.