Enzymatic cross-linking of whey proteins in low fat Iranian white cheese

The effects of cheese milk treated with transglutaminase (TGase) simultaneously with rennet addition, with and without enrichment with whey protein isolate (WPI), on the chemical and textural characteristics of low fat Iranian white cheese were investigated. Enzymatic treatment of milk increased the moisture content, cheese yield and the ratio of moisture-to-protein (M:P), resulting in decreased fracture stress and Young's and storage (G′) moduli. When TGase was added to cheese milk after fortification with WPI, a higher protein recovery and hardness indices were obtained in comparison with the sole addition of TGase. Scanning electron microscopy images revealed a compact and dense microstructure in the control low fat cheese, explaining the harder texture of the sample. Cheese milk fortification with WPI and TGase treatment increased the number of serum pools within the microstructure in accordance with the trend observed for M:P.