Characterization of cryogel monoliths for extraction of minor proteins from milk by cation exchange

Abstract

Extraction and purification of high-value minor proteins directly from milk without pre-treatment is a challenge for the dairy industry. Pre-treatment of milk before extraction of proteins by conventional packed-bed chromatography is usually necessary to prevent column blockage but it requires several steps that result in significant loss of yield and activity for many minor proteins. In this paper, we demonstrate that it is possible to pass 40-50 column volumes of various milk samples (raw whole milk, homogenized milk, skim milk and acid whey) through a 5 mL cryogel chromatographic column at 550 cm/h without exceeding its pressure limits if the processing temperature is maintained above 35 degrees C. The dynamic binding capacity obtained for the cryogel matrix (2.1 mg/mL) was similar to that of the binding capacity (2.01 mg/mL) at equilibrium with 0.1 mg/mL of lactoferrin in the feed samples. The cryogel column selectively binds lactoferrin and lactoperoxidase with only minor leakage in flowthrough fractions. Lactoferrin was recovered from elution fractions with a yield of over 85% and a purity of more than 90%. These results, together with the ease of manufacture, low cost and versatile surface chemistry of cryogels suggest that they may be a good alternative to packed-bed chromatography for direct capture of proteins from milk.

Integrated Downstream Processing of Lactoperoxidase from Milk Whey Involving Aqueous Two-Phase Extraction and Ultrasound-Assisted Ultrafiltration

“…Since then, various chromatographic techniques, based on ion-exchange procedures have been employed. However, most of these conventional multi-step techniques are not suitable for large-scale as they suffer from major limitations such as time-intensive, loss of activity and high-capital cost [6][7][8]. Nevertheless, the recovery of this dilute protein from whey is a relatively difficult task, not only because the huge volume of whey needs to be dealt with but also the presence of major proteins results in complication in the separation process.…”

Preparation of macroporous cryostructurated gel monoliths, their characterization and main applications

“…(B) Column backpressure versus total volume applied to the column for homogenized whole milk (3% fat) samples loaded at various flow rates at 35–37°C. Reproduced from 15 with permission.…”

“…Polyacrylamide cryogels bearing weak cation‐exchange functionality were shown to retain their low backpressure at application of large volumes of homogenized whole milk at different flow rates (Fig. 3B) 15.…”

“…The size of macropores both in freeze‐dried and freeze‐thawed monoliths is regulated mainly by freezing conditions and composition of the initial reaction mixture. Depending on the potential application, the cryostructuration platform allowed for the production of monolithic stationary media for processing the (bio)particles containing fluids 7–11, for protein purification 12–16 as well as materials for biomedical applications. This review summarizes the recent research on the preparation and characterization of cryostructurated monolithic media for (bio)separation and points to some future perspectives.…”

Isolation of immunoglobulin G from bovine milk whey by poly(hydroxyethyl methacrylate)‐based anion‐exchange cryogel

“…Naturally, bovine milk is a viscous mixture containing fat colloids, proteins, and other active ingredients and thus cryogels could be a potential class of adsorbents for the separation of milk proteins. Billakanti and Fee have used cation‐exchange cryogel to separate minor proteins directly from raw milk. They obtained LF with a yield of over 85% and a purity of more than 90%.…”