Insight into aroma attributes change during the hot-air-drying process of white shrimp using GC-MS, E-Nose and sensory analysis

Aroma attributes are one of the most important criteria that affect the flavor quality of dried shrimp, but the dynamic changes of aroma attributes remain largely unknown during the drying process. The present study investigated aroma attributes change during the hot-air-drying process of shrimp using gas chromatography-mass spectrometry (GC-MS), electronic nose (E-nose) and sensory analysis. The potential correlations among volatile compounds, sensory attributes and E-nose data were analyzed by partial-least-squares regression (PLSR). Results showed that the aroma characteristic of shrimps changed significantly during processing. The odor in the fresh shrimp was very light, and the key aroma compounds mainly consisted of trimethylamine and three aldehydes. The aroma characteristics mainly consisted of roasted and meat-like odors had come into being gradually with the decrease of water activity (Aw), and the aroma attributes were the most acceptable at about Aw 0.274 (hot-air drying for 7 h). Four kinds of aroma-active compounds (pyrazines, amines, aldehydes and heterocyclic compounds) made important contributions to the formation of aroma characteristics. The PLSR result showed a good correlation between most variables of volatile compounds, E-nose data and sensory attributes.