Effect of high-pressure homogenisation on the retention of selected aroma compounds in model dairy emulsions

The aim of this work was to investigate the effects of high-pressure homogenisation on the aroma retention of mixed sodium caseinate-whey protein (2% + 2% w/v) emulsions. For this purpose, raw and pasteurised emulsions, with different fat contents (5%, 8% and 15% w/v) and subjected to different homogenisation pressures (0, 18, 100 and 150 MPa), were produced. The retention of seven aroma compounds (hexanal, benzaldehyde, diacetyl, ethyl butyrate, isoamyl acetate, ethyl hexanoate and ethyl octanoate) was evaluated by static headspace gas chromatography. Results showed that aroma release was affected by the presence and the quantity of the lipid phase. As regards homogenisation, an increase in the retention of hexanal with homogenisation pressure was observed and interactions between hexanal and caseinate were suggested. Benzaldehyde showed significant changes in headspace partition with increasing pressure only in the 5% fat content emulsions, whereas no homogenisation effect on aroma retention was observed for diacetyl or esters. © 2014 Institute of Food Science and Technology.