Volatile Compounds Analysis of Fermented Cow Milk during Fermentation and Storage Using the Starter Streptococcus thermophilus ND03

Abstract:

The aim of the research was to study the volatile compounds of fermented cow milk during the fermentation and storage period at 4 ℃ using the starter strain named Streptococcus thermophilus ND03 with the method of solid phase microextraction and gas chromatography coupled with mass spectrometry（SPME-GC-MS） by three different extraction fibers. The numbers of extractions detected by different extraction fibers named 50/30 ?滋m DVB/CAR/PDMS，65 ?滋m PDMS/DVB and 100 ?滋m PDMS were 86，66 and 62，respectively. The amount and the content of volatile compounds showed significantly different between the process of fermentation and storage period. The principal component analysis results showed that aldehyde compounds，ketone compounds and heterocyclic compounds were the characteristic aroma species of samples during fermentation period. In the storage period，alcohols and nitrogen-containing compounds were the characteristic aroma species of samples named stored 0 d，namely end-point of fermentation；aromatic compounds and esters compounds were found to be the characteristic aroma species of samples named stored 1 d and 3 d；acid compounds and hydrocarbons were the characteristic aroma species of samples of stored 7 d and14 d. The sensory evaluation results suggested that the samples named stored 1 d showed good performance in color，taste，flavor and texture. All in all，Streptococcus thermophilus ND03 as the starter culture has potential industrial application prospect.