Improving the Yield of Mozzarella Cheese by Phospholipase Treatment of Milk

Hydrolysis of milk by Fusarium venenatum phospholipase A₁. Degree of hydrolysis (DH) of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) as a function of incubation time. The error bars represent standard errors of the mean for 2 replicates.

A continuous spin–spin relaxation time (T₂) distribution of fresh Mozzarella cheese curd, measured by low-resolution ¹H nuclear magnetic resonance. Solid line=control cheese; dotted line=cheese made from phospholipase-treated milk.

Development of the peak intensity (A) of the 2 dominating peaks in semi-skim Mozzarella cheese at 3 wk after manufacture. ˙=A₁ of control cheese; ■ =A₁ of phospholipase (PL) cheese; ○=A₂ of control cheese; □=A₂ of PL cheese. The error bars represent standard errors of the mean for 3 to 5 replicates.

Development of T₂ relaxation times of the 2 dominating peaks in semi-skim Mozzarella cheese at 3 wk after manufacture. ˙=T_2,1 of control cheese; ■ =T_2,1 of phospholipase (PL) cheese; ○=T_2,2 of control cheese; □=T_2,2 of PL cheese. The error bars represent standard errors of the mean for 3 to 5 replicates.

Development of the microstructure in semi-skim Mozzarella cheese at 4 wk after manufacture. A to D: control cheese; E to H: cheese made from phospholipase-treated milk. A, E: fresh, unsalted cheese curd prior to stretching; B, F: after 3 d; C, G: at 14 d; D, H: at 28 d. The image size is 240×240μm.

Fat globules in semi-skim Mozzarella cheese prepared with phospholipase at 28 d after manufacture. The image size is 60×60μm.