Whey proteins are a valuable ingredient with unique functional and nutraceutical characteristics. Adding them to products such as dairy drinks, cheeses or nutritional supplements can add value and increase the competitiveness of the product, and therefore their processing and recovery are of great importance for dairy processors. However, the quality of the resulting products depends on their purity. Unwanted bacteria, spores and somatic cells as well as non-milk constituents such as carbohydrates and fats must be efficiently removed from the milk or whey. This is a job that the GEA bacteria removal separators reliably and cost-efficiently perform.유청분리기추천
The GEA range of separators includes one-stage, two-stage and special bacteria separation from drinking and vat milk as well as for cheese-making milk. The GEA separation technologies are also applicable to the treatment of whey concentrate and other products from whey protein production.
A common method for separating whey protein molecules is affinity chromatography. In this technique, a specific ligand is covalently attached to the support matrix of the chromatographic column. The ligand attracts and binds only to a particular protein molecule, thereby separating it from other proteins that do not recognize the ligand. The bound molecule can then be eluted by changing the buffer pH, increasing the ionic strength, using a metal chelator, or by a combination of these approaches.
Another chromatographic separation technique that can be used for the isolation of whey proteins is gel filtration. In this process, a column is filled with a cellulose gel. The cellulose gel has a high porosity and can be charged or uncharged. Various cellulose derivatives are available, such as hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC) and poly(2-hydroxyethyl methacrylate) (carboxy-PAAm). The ability to use these materials for a wide variety of operating conditions makes this technology particularly suitable for separating proteins.
In a recent study, the ion exchange separator was used to separate IgG and growth factors from raw milk and acid whey with a high purity (95% and 98% respectively). The results were comparable to those of other ion exchange membranes. However, the performance of these ion exchange membranes was significantly improved by using an electric field in the separation process. This technique is also known as electrically enhanced ultrafiltration (EUF).
Ion exchange chromatography is an established separation method for whey proteins, and the performance of ion exchange resins can be optimized by selecting different ionic groups for their functionalization. For instance, cation exchangers with sulfopropyl (SP) and carboxylethyl (CM) ligands have been used to capture positively charged proteins in a range of buffers from neutral to acidic. The resulting eluates can be separated into four fractions – ALA, LP and BLG – depending on the elution buffer.
A single-step expanded bed adsorption process with a cation exchanger like Fastline SP was used to successfully isolate LF from crude sweet whey [147]. The percentage of eluted LF and BLG increased by using higher concentrations of salt in the elution buffer. The separation efficiency of the adsorption and subsequent gel filtration steps can be increased by using an ion exchanger with a lower molecular weight cut-off and an appropriate elution pH for each type of whey protein.베어그릭스