Effect of pH adjustment on production and physicochemical properties of cheese feed made of Irish Cheddar cheese

The effect of emulsification pH on the composition and colloidal stability of cheese feed (the spray dryer feed of cheese powder) was investigated in the absence of emulsifying salts (ES) to understand the sole effect of emulsification pH and to give insights into ES removal from cheese powder production. Cheese feeds were prepared at six different pH values from 5.1 to 6.8. Adjustments of pH during feed production had a significant impact on the mass fraction of several components (i.e., fat, calcium) between feed and retained mass (RM) obtained after sieving. These differences were primarily attributed to electrostatic changes among proteins during the emulsification process. pH-induced alterations in feed composition were associated with a significant change in particle size, viscosity, and colloidal stability. Confocal microscopy images of feeds revealed differences in protein aggregation and fat cluster formations. Raman spectroscopy of RM indicated alterations in protein structure by increased pH.& COPY; 2023 Elsevier Ltd. All rights reserved.