3
rdFood Structure and Functionality Forum & 3
rdIDF Symposium on Microstructure of Dairy Products
Process design for improving melting properties of
processed kashar cheese matrix in the presence of mTG
Tuğba BULAT
1, Ali TOPCU
1, H.Barbaros ÖZER
2*1
Hacettepe University Faculty of Engineering Department of Food Engineering, Ankara, Turkey
2
Ankara University Faculty of Agriculture Department of Dairy Technology, Ankara, Turkey
* Corresponding author: [email protected]
Abstract
Kashar cheese is a pasta-filata cheese. Major problem associated with Kashar cheese production in association with mTG was melting during scalding process. Additional cross-linking formed by mTG led to resistance of the Kashar cheese mass against melting. After a series of preliminary trials, it was noticed that adverse effect of mTG-triggered protein crosslinkings could be overcome by optimizing acidification rate of milk during curd formation. Rate of colloidal calcium release from para-kappa-casein matrix is of critical importance in melting.
Material and Methods
Effects of production parameters including mTG doses (0.50 to 1.0 U/g protein), milk pH at which mTG was added (6.3), starting pH of curd for cheddaring (5.7), pasteurization norm (68 °C/5 10 min), level of emulsifying salt mixture (0.8 to 1.2 %) (KASOMEL 3112/2185), scalding time (2 min) and temperature (79-80 °C) were considered for optimization studies. The yield, melting (by small angle temperature sweep test) and small/ large deformation textural/rheological properties of the cheeses were analyzed for 45 days. The activity of mTG was 100 U/g protein. mTG was obtained from Ajinomoto Foods Europe.
Results & Conclusion
Table 1. Yield values of wet and dry scalded processed heeses
Figure 2. Variation in the average shear viscosity (Pa.s) values of the wet scalded (A) and dry scalded (B) cheeses during 45-day of storage
(A) (B)
Figure 1. Shear viscous modulus of the 1-day old processed cheeses
manufactured by wet (A) or dry (B) scalding procedure (temperature sweep test)
Results showed that major factors affecting melting and stretching properties of Kashar cheese were pH of milk at the time of mTG addition, pasteurization temperature and ratio of emulsifying salts. Based on the yield and rheological data obtained, the process conditions for mTG-modified processed Kashar cheese were set as follows: pH of milk at the time of mTG addition, 6.3;
pasteurization norm, 68 °C for 10 min, cheddaring at pH 5.80 at 39 C for 40 min, scalding at 80 °C for 2-3 min in the presence of emulsifying salts at a level of 1.0% (KASOMEL 3112/2185 ratio of 70:30). Increase in moisture adjusted yield of the resulting cheese was 1.68%.
To conclude, mTG application in Kashar cheese production is feasible with regard to increased yield and textural properties. Optimum level of mTG for wet and dry scalded cheeses is 0.75 U/g protein and optimum emulsifying salt level is 1.0 % (w/v).
MACY: Moisture adjusted cheese yield
