Abstract: Considering the main cause and positions of quality deterioration and the complexity of detecting newly generated compounds in pork during frozen storage, headspace-gas chromatography-ion mobility spectroscopy (HS-GC-IMS) was chosen as a method for odor deterioration analysis to acquire and analyze the volatile organic compounds (VOCs) generated from lipid oxidation on the surface layer and shallow layer of frozen pork. Dimensionality reduction of the VOCs data of frozen pork stored for different periods was performed by principal component analysis (PCA), and the processed data were applied to establish a discriminant analysis model by K-means algorithm. The model was used to assess frozen pork stored for different periods. The results showed that the VOCs with similar polarity in frozen pork were separated effectively, and the data acquisition and analysis of VOCs were completed within 600 s by HS-GC-IMS. After data screening, 29 VOCs showed obvious changes in ion peak intensity, which?could be displayed in the 2-dimension mode of data visualization. The model developed in this study could classify samples of frozen pork at different storage times into the corresponding clusters.

Key words: headspace-gas chromatography-ion mobility spectroscopy (HS-GC-IMS), frozen pork, storage time, quality deterioration, lipid oxidation