Impact of freezing on the physicochemical and functional properties of low–moisture part–skim mozzarella

Low–moisture part–skim (LMPS) mozzarella cheeses were held at 4 °C for 0, 2 or 8 d before freezing to −20 °C. The cheeses were frozen at a rate of 0.6, 2.0 or 8.0 °C h−1 and held frozen at −20 °C for 1, 6, 12 or 44 weeks. After freezing, cheeses were stored at 4 °C for 16–37 d, resulting in a total storage time at 4 °C (before and after freezing) of 24–37 d (frozen–thawed mozzarella). Control mozzarella was stored at 4 °C for 25–37 d. The control and frozen–thawed cheeses were assayed for composition, primary proteolysis, moisture distribution, texture profile analysis and melting characteristics after similar storage times at 4 °C. Freezing under the evaluated conditions resulted in reduced firmness of the unheated cheese but did not significantly affect the properties of the heated cheese. The results suggest that freezing may be effectively applied to control or extend the functional shelf–life of LMPS mozzarella shipped to long–distance markets.