Influence of the Temperature of Salt Brine on Salt Uptake by Ragusano Cheese

Abstract

The influence of temperature (12, 15, 18, 21, and 24 degrees C) of saturated brine on salt uptake by 3.8-kg experimental blocks of Ragusano cheese during 24 d of brining was determined. Twenty-six 3.8-kg blocks were made on each of three different days. All blocks were labeled and weighed prior to brining. One block was sampled and analyzed prior to brine salting. Five blocks were placed into each of five different brine tanks at different temperatures. One block was removed from each brine tank after 1, 4, 8, 16, and 24 d of brining, weighed, sampled, and analyzed for salt and moisture content. The weight loss by blocks of cheese after 24 d of brining was higher, with increasing brine temperature, and represented the net effect of moisture loss and salt uptake. The total salt uptake and moisture loss increased with increasing brine temperature. Salt penetrates into cheese through the moisture phase within the pore structure of the cheese. Porosity of the cheese structure and viscosity of the water phase within the pores influenced the rate and extent of salt penetration during 24 d of brining. In a previous study, it was determined that salt uptake at 18 degrees C was faster in 18% brine than in saturated brine due to higher moisture and porosity of the exterior portion of the cheese. In the present study, moisture loss occurred from all cheeses at all temperatures and most of the loss was from the exterior portion of the block during the first 4 d of brining. This loss in moisture would be expected to decrease porosity of the exterior portion and act as a barrier to salt penetration. The moisture loss increased with increasing brine temperature. If this decrease in porosity was the only factor influencing salt uptake, then it would be expected that the cheeses at higher brine temperature would have had lower salt content. However, the opposite was true. Brine temperature must have also impacted the viscosity of the aqueous phase of the cheese. Cheese in lower temperature brine would be expected to have higher viscosity of the aqueous phase and slower salt uptake, even though the cheese at lower brine temperature should have had a more porous structure (favoring faster uptake) than cheese at higher brine temperature. Therefore, changing brine concentration has a greater impact on cheese porosity, while changing brine temperature has a larger impact on viscosity of the aqueous phase of the cheese within the pores in the cheese.

Interaction of Brine Concentration, Brine Temperature, and Presalting on Salt Penetration in Ragusano Cheese

“…There was a small impact (P = 0.01) of BT on overall salt content in portions P3 and P4 (Tables 7 and 8 and Figure 14). This was consistent with a previous report (Melilli et al, 2003b) that the higher the BT, the higher the salt content (Figure 14). However, although the impact of BT was significant, the absolute differences in salt content (over this small range of temperature) were not large.…”

“…However, BT did have a consistent influence (P ≤ 0.05; Tables 9 and 10) on salt in moisture in the P2, P3, and P4 portions with cheeses at lower BT achieving lower salt in moisture ( Figure 17) after 24 d of brining, but the magnitude of the impact of BT on salt in moisture was very small compared with the impact of PS and BC. This is consistent with the previous report of Melilli et al (2003b). Decreasing BT increases the viscosity of the water phase (Walstra et al, 1999) and this would tend to have more impact in the interior portions of the cheese because the salt taken up from the brine has a longer distance to travel through a more viscous water phase.…”

“…Thus, the combination of PS plus lower BC produced a higher salt in moisture content in the interior portions (Figures 15 and 16), particularly during the first 8 d. The P4 portion of the PS cheeses at d 0 had about the same salt in moisture content as a cheese that had been in SB for 16 d without PS. Higher salt in moisture content during the early stages of brine salting, particularly when brine temperature is >18°C, should help control early gas production (Melilli et al, 2003b). The main effect of BT in P1 was not significant (P = 0.59; Tables 9 and Journal of Dairy Science Vol.…”

“…Turhan and Kaletunç (1992) found that for White cheese, a semihard pickled cheese (Carić, 1993), the salt penetration was slower with de-creasing BT because of decreased salt diffusivity. Melilli et al (2003b) determined that salt uptake in Ragusano cheese increased with increasing BT from 12 to 24°C, but at brine temperatures higher than 18°C a stimulation of early gas production was noted, even though the salt uptake by the cheese was faster. Reducing brine temperature from 18 to 12°C made a larger reduction in early gas formation in cheeses that were not presalted (from 6.8 to 1.8% gas holes, respectively) than in cheeses that were presalted (from 1.9 to 0.5% gas holes, respectively; Melilli et al, 2004b).…”

Influence of brine concentration and temperature on composition, microstructure, and yield of feta cheese

“…Calcium concentrations of 0.5 to 0.6% in brine are needed to prevent leaching of calcium from the cheese surface and its increased hydration resulting in "soft rind" defects (Geurts et al, 1972). Increasing the salt concentration of brine will give faster salt diffusion and lower final cheese moisture (Prasad and Alvarez, 1999) but at very high levels, such as in saturated brine, "salting-out" can occur, causing a contraction of the protein matrix and reduced salt diffusion (Melilli et al, 2003).…”