Effect of ohmic heating in bioactive peptides, volatile compounds, and fatty acid profile in a high-protein vanilla flavoured milk drink

Abstract

High-protein vanilla flavoured milk was processed using ohmic heating (OH) at 60 Hz and 60, 80, 100 and 120 V (5.22, 6.96, 8.70 and 10.43 V cm−1, respectively), coded as OH60, OH80, OH100, and OH120, respectively. Peptide, volatile compounds, and fatty acids profiles were compared with untreated and pasteurised samples. Pasteurisation or OH resulted in loss of a β-casein peptide fraction with ACE-inhibitory activity, volatile compounds (1-pentanol, cyclohexanol, isobutyl butyrate, and ethyl decanoate), and fatty acids. However, OH processing released desirable volatile compounds (acetaldehyde, α-phellandrene). The application of intermediate electric field strengths (OH100) resulted in forming of a β-casein peptide with ACE-inhibitory activity and desirable volatile compounds (acetic acid, 2-pentanone, and 3-methyl-1-butanol), while maintaining butyric acid concentration and monounsaturated and polyunsaturated fatty acid levels more similar to the untreated product. The results suggest that OH, mainly at 10.43 V cm−1, is a promising technology in the development of milk drinks.