Evaluation of volatile flavor compounds in rice with different degrees of roasting based on GC-IMS and PCA analysis

Abstract

The differences of volatile odorants of rice at different roasting levels were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) using fingerprints combined with principal component analysis (PCA). GC-IMS and PCA could distinguish the different roasting levels of rice and the results showed that a total of 47 representative flavor compounds were detected in four samples from all roasting stages. The aroma components of roasted rice are mainly aldehydes and ketones, furans and pyrroles, as well as a large number of phenols, esters and alcohols, which make up the special aroma flavor of roasted rice. It can be seen that the flavor characteristics of roasted rice can be reflected more fully when the rice is roasted in medium (18 min), and can have more fruit wood, cream and roasted aromas. The PCA based on the signal intensity of the detected volatile compounds revealed effective differentiation of samples from different stages into comparatively independent spaces. Thus, the differences of volatile compounds from different roasting stages of rice were determined, and the flavor fingerprints of that can be successfully established using HS-GC-IMS and PCA.

Keywords:
rice; roasted, flavor fingerprint; principal component analysis; volatile profile; gas chromatography-mass spectrometry