Milk Fat Globule Membrane: a new tool for flavour development in cheese

This study investigated the impact of milk fat globule membrane (MFGM) isolation methods on the MFGM composition, xanthine oxidase (XO) activity and system oxidation-reduction potential (ORP).MFGM fractions were isolated from fresh cream churned at different temperatures (10, 15, 20°C) andpH values (5.5 and 6.6). MFGM was also obtained from commercial sources; freeze dried α-serum and β-serum, and spray dried buttermilk powder (BMP). Higher churning temperatures and cream pHresulted in a higher proportion of non-membrane proteins and a significant decrease in the XO contentand XO activity. Lower churning temperatures and cream pH gave a higher XO activity and resulted in emulsions with more positive ORP values. Commercial sources were enriched in MFGMcomponents, but did not reduce the ORP of the system as much as the laboratory made samples. TheORP of unprocessed milk is between +200 and +300 mV, thus a more negative ORP (-326 to -580 mV), as achieved in this study, has the potential to modify flavour development in low-fat cheese. Byaltering churning conditions, it should be possible to produce MFGM fractions with specific ORPreducing abilities for targeted flavour development

Keywords:

Milk fat globule membrane , xanthine oxidase , oxidation-reduction potential , emulsion , flavour development , cheese