Effect of whey nanofiltration process combined with diafiltration on the rheological and physicochemical properties of ricotta cheese

Whey after thermocalcic precipitation (TP) was submitted to nanofiltration (NF) and to nanofiltration followed by diafiltration (NF/DF). Because of their high protein content, the NF and NF/DF retentates from volume reduction factor (VRF) equal to 2.0 were chosen to produce ricotta cheese 1 and ricotta cheese 2, respectively. The ricotta cheeses were evaluated for their physicochemical, color, theological and microstructural properties. No differences were noted between the protein contents and total solids of the ricotta cheeses produced through NF and NF/DF retentates. However, considering the low luminosity values, it was possible to note that the color parameters of ricotta 1 were more affected by manufacturing. The same occurred for the rheological properties, indicating that ricotta 1 showed greater deformability before cheese rupture, which was also confirmed through its greater hardness. All the ricotta cheeses were characterized by a tendency to be more viscous than elastic, which was confirmed by their microstructural characteristics. Therefore, the ricotta cheeses obtained from NF and NF/DF retentates can be considered a good alternative for utilization of whey. (C) 2013 Elsevier Ltd. All rights reserved.