Abstract: To investigate the effects of constant high-temperature sterilization (HTS) and gradient heating sterilization (GHS) on the volatile flavor compounds of braised beef under the same sterilization intensity, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), electronic nose analysis and sensory evaluation were used to analyze the unsterilized (US), HTS (121 ℃ for 15 min), GHS1 (115 ℃ for 25 min, followed by 118 ℃ for 30 min), and GHS2 (115 ℃ for 30 min, followed by 121 ℃ for 6 min) samples. The results showed that GHS had a significant impact on the content of volatile flavor compounds. A total of 59 volatile flavor compounds were detected in the four groups of samples. The total contents of volatile flavor compounds in the US, HTS, GHS1, and GHS2 samples were 639.53, 897.83, 1 223.46, and 1 953.93 μg/kg, respectively, with phenols, aldehydes, alcohols, and other compounds being relatively more abundant. Moreover, the content of volatile flavor compounds was significantly higher in group GHS2 than in the other groups (P < 0.05). Based on odor activity values (OAVs), eugenol, eucalyptol, geraniol, 1-octen-3-ol, nonanal, n-octanal, 4-allylanisole, and anethole were the major characteristic flavor compounds of the product. From the results of electronic nose and sensory evaluation, it was found that GHS2 had a better effect on the generation and retention of characteristic flavor compounds. In conclusion, GHS2 was more effective in maintaining the flavor characteristics and overall sensory properties of braised beef.

Key words: braised beef; gradient heating sterilization; constant high-temperature sterilization; volatile flavor compounds