The manufacture of cheese from cow’s milk generates hundreds of litres of by-products every day in Québec and around the world. Indeed, for every kilogram of cheese produced, nine litres of whey are produced and must be reprocessed or disposed of. This means that 90% of the raw material ends up as a by-product! How can whey be better valorized from the outset? Mohammed Aider, a professor of food engineering at Université Laval’s Faculty of Agricultural and Food Sciences, looked into this question.

Whey contains mainly water, a little protein, lactose and mineral salts. In most industrialized countries, the dairy industry extracts protein, a marketable by-product, from the whey. However, this process also generates another by-product, whey permeate, which has limited use due to its low added value.

Professor Aider decided to use electro-activation technology to transform some of the lactose into lactulose, a prebiotic widely used in the pharmaceutical and biotechnology industries. Lactulose is used to enhance the growth of probiotic bacteria. In addition to generating a product with significant potential and commercial value thanks to its high lactulose content, electro-activation, which runs entirely on electricity, does not require the use of highly corrosive chemicals as does conventional processing. This method therefore reduces the number of processing steps, as it requires a single transformation rather than having to fractionate whey twice, thus offering a simpler, more sustainable, safer option.

The concept, which now needs to be scaled up, could provide an efficient and more environmentally-friendly solution for the complete valorization of cheese manufacturing by-products, thus promoting a circular economy.