In natura ovine whey proteins concentration by ultrafiltration combining batch and diafiltration operating modes

摘要

The objective of this study was to concentrate the ovine cheese whey proteins using ultrafiltration (UF). Two different experiments were carried out: in Experiment 1, the whey was concentrated using the batch-operating mode until a volumetric concentration factor (VCF) of 4, followed by two steps of diafiltration (DF). In the second experiment, an aqueous solution of calcium chloride (0.5 L of CaCl2-60 g/L) was added in order to change the ionic strength of the feed solution, and the same process parameters were used (VCF = 4; DF = 2 steps). For both experiments was observed high occurrence of fouling, in Experiment 1, the water permeance decreased from 38.8 to 1.5 L m(-2)hr(-1)bar(-1)(96.2% of fouling), and in Experiment 2 decreased from 38.0 to 1.0 L m(-2)hr(-1)bar(-1)(97.4% of fouling). The results indicated that the addition of CaCl(2)promoted greater protein aggregation and precipitation, resulting in higher protein retention (99.1%). DF steps increased the protein purification in the concentrate fraction, evidencing that UF/DF processes are suitable for whey protein concentration. Practical Applications This work takes into account the concentration of ovine cheese whey proteins by the ultrafiltration (UF) process. Whey has a high functional and nutritional value since it contains proteins, lactose, and minerals. Specifically, ovine whey has higher protein content in comparison to bovine whey, which makes it a product of greater interest. It is important to emphasize that there is little literature about ovine whey processing. Moreover, one differential of this work was the use of the DF operation mode combined with the UF process, which can improve protein concentrate characteristics. Another differential was the use of fresh ovine whey, showing a more realistic scenario since it involves a feed stream with more complexity, which can expand the ideas for practical possibilities of application. From a novelty perspective, although UF of bovine whey has been studied a lot, the process for ovine whey has not still been studied extensively and deserves attention.