Salt-induced structural changes in 1-day old Mozzarella cheese and the impact upon free oil formation

Mozzarella cheese was manufactured to different salt levels by either a combination of dry- and hot-brine salting, or by cold-brine salting alone. Dry- and hot-brine salting resulted in a higher moisture content compared to cold-brine salting at equivalent salt levels. Increasing levels of salt with either salt treatment decreased the amount of expressible serum, increased apparent viscosity, but had no effect on free oil formation. There was no effect of salt on fat globule size and shape, or on the relative amounts of fat polymorphs (alpha, beta' and beta crystals). Cooling the cheese at a lower temperature of 0degreesC after the cooking and stretching stage decreased the amount of free oil and increased expressible serum compared to cooling at 8degreesC. There was no effect of cooling temperature on the melting point of milk fat in the cheese, however the lower cooling temperature did decrease the relative amount of beta crystals. (C) 2004 Elsevier Ltd. All rights reserved.