Abstract：Changes in the total volatile basic nitrogen (TVB-N) and total bacterial count (TBC) of fresh beef during storage at 4 ℃ were measured. Changes in the categories and relative contents of volatile components were also investigated by purge/trap-thermal desorption system-gas chromatography-mass spectrometry (P&T-TD-GC-MS). The results showed that both TVB-N and TBC increased significantly with the extension of storage time. TVB-N exceeded the maximum limit for fresh meat and TBC approached to the maximum limit stipulated in the Chinese national standard after 6 days of storage. The relative contents of acids, alcohols and ketones showed an increasing trend during cold storage, the content of aldehydes increased firstly and then decreased, while aromatic hydrocarbons decreased gradually. Amine substances were detected on the 8th day. The changes in volatile components could characterize beef freshness to a certain extent.
