Food Engineering

New processing technique yields new protein concentrate

April 4, 2003
Researchers at Ithaca, N.Y.-based Cornell University believe that the true gold in cheese plants could be pure milk serum proteins that are separated from liquid milk before it is used to make cheese.

Along with the Northeast Dairy Foods Research Center (NDFRC), scientists at Cornell University have refined a microfiltration process to separate the casein and milk serum proteins from liquid milk instead of the whey stream. The serum proteins and native casein contain none of the colorants, enzymes and cultures used during cheese manufacture.

The pore size of the filter determines the type and size of molecules researchers retain. Depending on whether the objective is to make a concentrated milk-derived food ingredient or to separate individual components from the milk, researchers can adjust the filters accordingly, yielding a customized fluid permeate and equally customized retentate.

Scientists indicate that one way microfiltration could improve the efficiency of cheesemaking is through the production of customized concentrated retentate. Using low concentration factor retentates (2 to 3X) to fortify unfiltered milk yields an improvement in cheese manufacturing efficiency and costs. Using a high concentration factor (8 to 12X) would further increase the efficiencies, providing little or no whey drainage from the cheese.

In either case, a milk serum protein concentrate (SPC) would be produced from the microfiltration permeate from the liquid milk and would be a higher value co-product of cheesemaking than traditional whey products, according to Sy Rizvi and David Barbano, both professors of science at Cornell. "Functionally and nutritionally, this SPC differs from traditional whey products," said Barbano. "There could be an entire new spectrum of uses for this ingredient, and those uses remain to be discovered."

One key benefit to an SPC is consistency. Because the milk serum protein would be extracted from milk prior to cheesemaking - free if enzymes, colors and cultures - food formulators can expect consistency and purity from SPC.

Thus far, researchers have conducted testing and product development on a laboratory scale and are looking for an industrial partner for scale up.