Ultrafiltration and diafiltration modeling for improved whey protein purification
Camila Baldasso, Wendel Paulo Silvestre, N.I.B. Silveira, Ana Paula Vanin, Nilo Sérgio Medeiros Cardozo, Isabel Cristina Tessaro
Abstract
Whey is a byproduct of the dairy industry, obtained during the manufacture of cheese and casein. It is a promising feedstock for the food industry due to the functional and nutritional properties of its proteins. Ultrafiltration (UF), associated with diafiltration (DF), has been used in the industry to produce whey protein concentrates. This technology allows for a selective concentration of the proteins. The objective of this work was to concentrate and purify whey protein using UF and DF, also proposing a modeling scheme to maximize the process profit. The results obtained were used to estimate the parameters of a theoretical model aiming to optimize the UF/DF process. The protein content, according to the data from the simulation, would reach 98.6 wt.%, representing a final profit of US$ 81.00 per kilogram of product. Experimentally, to produce a product with a protein content of 70.0 wt.% (42 kg·m−3), up to 40 L of effluent can be produced. The results of the theoretical model reported that 67 L of effluent is generated when a product with a protein content of 98.6 wt.% (59 kg·m−3) is obtained. In this sense, despite the increase in effluent generation, the UF-DF coupled process, according to the model, may increase protein content to 98.6 wt.%, greatly increasing process profitability relative to a modest increase in effluent treatment cost.