Plant protein isolates were evaluated and used to replace skim milk powdered protein in processed cheese blends. The chemical composition of chickpea protein isolate (CPI), peanut protein isolate (PPI) and sesame protein isolates (SPI) were determined. Functional properties of the tested protein isolates were also studied. SPI had minimum emulsion activity index (EAI), while the PPI possessed the highest value. The emulsions formed remained stable after one day, then destroyed at the 3rd day. Water absorption capacity (WAC) of the tested protein isolates varried between 196 to 329 g water/100 g protein. The water-oil absorption index (WOAI) for CPI, PPI and SPI were 7.6, 0.48 and 0.90, respectively.
Changes in chemical composition of plant-type processed cheeses containing different levels of plant protein isolates (5, 10 and 15%), occurred only in total nitrogen, while the other constituents such as total solids, fat and salt were not affected. Sensory evaluation of the processed cheese revealed that total score gradually decreased with increasing plant-protein isolate levels up to 15% but still preferable for the consumer. This decrease in the total score regards the flavour but not to the colour or body and texture.