Acid coagulation properties and suitability for yogurt production of cows’ milk treated by high-pressure homogenisation

The effects of high-pressure homogenisation (HPH) of cows’ milk were investigated for suitability for yogurt manufacture, compared with the processes currently applied in industry. Milk at different inlet temperatures (30 °C or 40 °C) was subjected to HPH treatment at 100, 200 or 300 MPa (one stage) and 130, 230 or 330 MPa (two-stage). HPH-treated milk was compared with milk heat-treated (90 °C for 90 s) and homogenised at 15 MPa, and with milk treated under the same thermal conditions and also fortified with 3% skim milk powder. Milk treated at 300 or 200 MPa showed higher gel strengths on coagulation, higher gel firmness in texture analysis, less syneresis and lower titratable acidity compared with conventionally treated milk fortified with 3% skim milk powder.