How to profit from whey demineralization

Sweet whey is a by-product of hard and semi-hard cheese production. It naturally contains a significant number of minerals and organic anions (acids). All minerals together represent ash content which is approximately 8.0-8.5% ODB considered typical for natural sweet whey with total solids 5.5-6.5% (TS). Demineralization by MEGA electrodialysis enables to decrease the ash and acids content to obtain a product with a much better taste and the possibility of a further use.

MEGA electrodialysis units can process natural whey or whey concentrated up to 22% TS - 18 - 22% TS by evaporation (EV) or pressure membrane processes as reverse osmosis (RO) or nanofiltration (NF). This is preferred due to the higher conductivity of the feed after the concentration and the optimal efficiency of MEGA ED units. Thanks to the concentration and higher conductivity of the feed MEGA electrodialysis units can achieve high demineralization rates like D90 (1% Ash ODB) without using ion exchange.

Acid whey is a by-product of greek yogurt, soft cheese or quark production. Due to the high acidic properties with pH ranging from 4.7–5.3 caused by a high number of organic ions (lactate and citrate) and a large mineral content of approximately 9–11% ODB, considered typical for natural acid whey, with total solids 5.5-6.5% (TS) make it difficult for further processing. It can’t be evaporated without using special techniques with high operational costs and due to very low sensory attributes it can’t be reused internally either.

Electrodialysis is an elegant solution for all these issues. It goes hand in hand with the removal of minerals and especially of organic ions (acids). MEGA electrodialysis units can achieve pH values according to the customer’s needs by removing the organic ions (acids) and integrated pH correction. The results of the demineralization process of acid whey make the final product suitable for food grade products.

MEGA electrodialysis units can process natural acid whey or whey concentrated up to 22% TS - 18 - 22% TS by reverse osmosis (RO) or nanofiltration (NF), which is preferred due to the partial removal of monovalent ions and organic ions. Thanks to the higher conductivity of the feed after the concentration, MEGA ED units can work at the maximum efficiency to achieve high demineralization rates like D90 (1% Ash ODB) without using ion exchange even for acid whey.

After ultrafiltration of whey, up to 95% of the solution is rejected as permeate despite its high lactose content. The reason for rejection is a very high mineral content from 9% up to 12 % ODB and high acidity after the whey is filtrated.

By processing of the UF permeate with electrodialysis you can produce an edible food-grade lactose for further use in confectionery, bakery or animal feed. That means that you can expand your product portfolio and increase your revenue by utilizing a by-product of cheese production.

The electrodialysis process also minimizes the evaporator and spray dryer scaling issues of an untreated UF permeate. And in that way partially prevents costs connected with the after-treatment maintenance which makes it a very effective solution for multiple parts of your production process and provides you with cost-effective advantages.

Delactosed whey (DLW) or Mother Liquor (ML) is produced from concentrated whey which has been partly delactosed by crystallization. It is a saturated lactose solution (45-50% ODB) with a content of protein (26-33% ODB), organic acids and mineral substances (10-12% ODB), the total amount of dry matter is 40%. Due to a high volume of salts and acids, DLW/ML can’t be further reused as an animal feed.

The electrodialysis is an effective solution for reducing the salts and acids concentration after the original content of dry matter is diluted down to 18-22% in order to assure better hydrodynamic conditions of the electrodialysis process. The demineralized product can be reused in lactose production in order to increase the volume of the product. It means that it can be used either directly in liquid or spray dried.