The importance of volatile compound profile in the assessment of fermentation conducted by Lactobacillus casei DN-114 001

The focus of this study was to compare the volatile compounds of unfermented and fermented milk samples containing Lactobacillus casei DN-114 001. Samples were analysed by headspace solid phase micro extraction-gas chromatography-mass spectrometry and pH changes were monitored on day zero and at weeks 2 and 4 of storage at 6 °C. Acetic acid was present as the dominant compound in all fermented samples and non-fermented samples from the 2nd week of storage. Other identified compounds were: 2-butanone, ethanol, 2-pentanone, 2-heptanone, amylol, acetoin, 2-nonanone, propionic acid, butyric acid, isovaleric acid, caproic acid, dodecanol, and caprylic acid. Comparison of the volatile compound profiles using cluster analysis revealed a similarity of volatile compounds of fermented and unfermented milk samples stored for 4 weeks. Cluster-analysis comparison and an artificial neural network model enabled demonstration of the close relationship between model non-fermented milk and a commercially-available milk product.