Abstract:Based on the author’s previous study, immersion vacuum cooling with ultrasonic assistance (IVCUA), is further compared with immersion vacuum cooling (IVC), vacuum cooling (VC) and air blast cooling (AB) for the change of volatile compounds and microbial count in cooked pork ham. Electronic nose analysis results indicated that the differences on the volatile flavor compounds of cooked pork hams treated by different cooling methods could be sensitively detected using the electronic nose. The results of GC-MS analysis demonstrated that there were significant difference on the compounds of volatile flavor of cooked pork ham treated by different cooling methods, and 66, 70, 77 and 106 volatile flavor compounds were detected for VC, IVC, IVCUA and AB samples, respectively. VC, IVC and IVCUA samples had a higher loss on alcohol and hydrocarbon compared to those treated by AB. However, these losses didn’t produce a significant effect on the total produced flavors. Compared to IVC and VC samples, IVCUA samples had more compounds of volatile flavor including aldehydes, ketones and esters, which play an important role in the formation of total flavors. In addition, it was concluded that samples treated by IVCUA had a lower total viable count and lactic acid bacteria count compared to those subjected to AB, VC and IVC treatment during cold storage, indicating a longer shelf-life. Results confirmed that IVCUA is reasonable to cool the cooked meat products as an innovative cooling technology.
