Effect of cheese maturation on physical stability, flow properties and microstructure of oil-in-water emulsions stabilised with cheese powders

Cheese powders contain high levels of functional caseins. We investigated the emulsifying properties of cheese powders produced from cheese of various maturation times: 16, 30 and 45 weeks and with addition of 2% sodium caseinate plus 2% buttermilk powder or only with buttermilk powder at 4%. The cheese powders were used to stabilise oil-in-water emulsions at a concentration of 1.5% on protein basis. All emulsions exhibited non-Newtonian shear-thinning behaviour. Emulsions prepared with cheese powders made from more ripened cheeses (30 and 45 weeks) showed significantly (p ≤ 0.05) higher consistency index. Cheese powder produced from 16 weeks old cheese showed a higher degree of stabilisation with a gradual increase in phase separation over time. However, instability occurred faster when using 30 and 45 week-old cheeses, but to a lower extent, indicating that cheese maturation affects the degree and the kinetics of destabilisation of oil-in-water emulsions.