pH effect on the physico-chemical, microstructural and sensorial properties of processed cheese manufactured with various starches

Processed cheeses containing 5% w/w potato, waxy maize or corn starch were manufactured in the pH range 4.5–6 to investigate the effect of pH on the physical and microstructural characteristics of high-starch processed cheese. Increased hydrogen bonding between the starch alcohol groups and hydrophilic protein residues was observed with both increasing and decreasing pH, indicating a higher degree of starch distribution. Optical microscopy showed a continuous starch exclusion network in cheeses manufactured with native starch between pH 4.8–5.3, with discrete starch particles present at increased and decreased pH. This network breakdown reduced product hardness and increased meltability, with the 5% starch cheese manufactured at pH 6 exhibiting higher sensory acceptability compared to the non pH modified sample. The present work demonstrates that increasing cheese pH during manufacture can reduce the negative physical characteristics associated with high-starch processed cheese and may provide industry with a cost effective method to increase the sensory acceptance of such products.