Analysis of Volatile Flavor Constituents in Bamboo Bird’s Nest Soups with Headspace-Gas Chromatography-Ion Mobility Spectrometry

The content and regularity of volatile components in bamboo bird’s nest soups were explored to screen the best way to prepare bamboo bird’s nest soups. The bamboo bird’s nest soups made by microwave(WB),electric pressure cooker(DYL)and induction cooker(DCL). These samples were analyzed by amino acid automatic analyzer and gas chromatography-ion transfer spectrometry(GC-IMS)according to the relative odor activity value(ROAV)method and principal component analysis(PCA).The results showed that,DYL had the highest dissolution rate of solids and the highest total amount of free amino acids,while,the content of glutamic acid in free amino acid was the highest. The obvious differences of volatile organic compounds(VOCs)in three samples could be obtained by GC-IMS two-dimensional spectrum and fingerprint. In the fingerprint,the VOCs including 1-octanol,3-methyl butyric acid dimer and so on,as marked in frame B,mainly existed in WB. The VOCs including 2-octanone,nonanal,and so on,as marked in frame D,mainly existed in DCL. The VOCs including 2-methyl propionaldehyde,2-propanol and so on,as marked in frame F,mainly existed in DYL. There were significant differences in the contents of 2-methyl propionaldehyde and 2-propanol between DYL and the other samples(P<0.05). Aldehydes and alcohols were the main compounds in the identified VOCs. The result via ROAV method showed that the key flavor compounds of the three samples were similar,but the contribution was quite different. PCA analysis showed that the sum of PC1 61% and PC2 31% could distinguish the three samples well. Electric pressure cooker is the best tool for the preparation of bamboo bird’s nest soups. Based on the GC-IMS detection technology,it is feasible to distinguish the three cooking methods of bamboo bird’s nest soups,including WB,DYL and DCL,by detecting the VOCs.