Studies on low-moisture, part-skim mozzarella cheese from highly concentrated microfiltration retentate depleted of whey proteins and calcium.

摘要

Cheese production using ultrafiltration retentates has not fulfilled its initial promise for manufacture of Cheddar and Mozzarella cheese, mainly due to atypical cheese texture, slower proteolysis, and impaired functionality. Microfiltration (MF) processing can be used to partially remove two main causative factors from milk retentate, namely whey proteins (WP) and colloidal minerals. The objective of the present study was to develop a process for manufacture of low-moisture, part-skim (LMPS) Mozzarella cheese from highly-concentrated MF retentate, with evaluation of important manufacturing variables for effects on cheese and whey composition and on cheese rheological and functional properties.; A MF system was constructed and weight concentration factor (CF) 8–9 MF retentates were produced from skim milk at pH 6.6, 6.3, and 6.0 to quantify depletion of WP and colloidal minerals. Preliminary work determined pH 6.0 retentate as having the most appropriate composition for cheese manufacture. Concentrated pH 6.0 retentate and butteroil were transformed into LMPS MF Mozzarella cheeses (MFM) using the developed manufacturing process, with optimization studies using differing combinations of rennet concentration, coagulation temperature, and post-coagulation curd cutting time. Cheese acidity was developed using glucono-δ-lactone.; Cheeses were not compositionally different by treatment, although significant differences were present in coagulation time and pH 4.6 soluble N due to rennet concentration. Use of starter culture adjuncts accelerated proteolysis. Whey compositions differed significantly, primarily by rennet concentration and curd cutting time. The optimal combination of manufacturing treatments were rennet concentration of 80–100 μl/kg cheesemilk, coagulation temperature of 32–36°C, and post-coagulation curd cutting time of 15 minutes.; Rheological parameters of lubricated squeezing flow and stress relaxation were measured as was cheese meltability and stretchability. Cheeses became significantly less elastic and more flowable over time with increasing rennet concentration and with use of starter culture. MFM rheological change was delayed versus control LMPS Mozzarella and was attributable to partial inhibition of rennet and milk plasmin by remaining WP, lack of starter culture proteases, and cheesemilk homogenization. The developed manufacturing process, along with increased concentrations of residual rennet and use of starter culture, can normalize proteolysis and improve rheological and functional development of MF Mozzarella cheese.