Changes of the bacterial colonies and volatile substances in shrimp paste at different temperature and time

Objective: Study the effects of temperature and time on the bacterial colonies and volatile substances in shrimp paste.Methods: Using 3M Petrifilm plate to detect microorganism of shrimp paste in different temperature( 4,16,30 ℃) at a certain time.The electronic nose( E- nose) and headspace solid phase micro extraction( HSSPME) combined with gas chromatography- mass spectrometry( GC- MS) were used to analyze the volatile compounds in shrimp paste at different conditions.Correlation between the changes of volatile compounds and the total numbers of colony was established in shrimp paste.Results: The total numbers of colony was respectively 103,105,107 in the experimental period under the storage temperature of 4,16,30 ℃.The detection signal of volatile substances of E- nose dates changed significantly with the increase of the bacterial colonies.The results of GC- MS showed that the shrimp paste mainly contained aldehydes,alcohols,ketones and other volatile compounds.These compounds had a significant difference in variety and relative content in different conditions.Conclusion: The results showed that the temperature had a great influence on total numbers of colony and volatile compounds in the shrimp paste.Temperature and time led to the changes of the total number of colonies,thus affecting the microbial metabolism and changing the varieties and relative contents of the volatile substances in shrimp paste.