7.3.2 Stage 2: Product design and process development

A number of critical product qualities emerged from the product concept that required process investigation and development. Although some whey protein powders had been made previously, they were a substantial distance from the demanding specification that was deemed necessary for the proposed product concept. This was for a higher (90%) protein content, and for much reduced fat and lactose.

To achieve these, increased use could be made of membrane separations. These would be used to remove the larger fat globules, but ran the risk of carrying some protein with the fat that would reduce the yield. So it was necessary to investigate preliminary modification of the flocculation of the fat globules before the microfiltration steps. Lactose, being a small molecule, would pass through the membranes with the protein, but it could be broken down into simpler sugars using enzymes.

Then came exploration of the ion exchange by which, after altering the acidity, the protein could be fastened and removed from the liquid whey on the ion-exchange resin and then subsequently unfastened and detached from the resin by altering the acidity again.

All of these steps required careful exploration so that they would not only work in the laboratory, but also could be designed for full-scale plant operation, controlled sufficiently tightly to meet the specifications, and then transferred to a working factory for manufacture.

Along with the chemical composition, perhaps the most vital element of the product specification was the functional properties of the product, those properties that would make it uniquely suitable for its intended use and clearly superior to the competition. Important properties were:

     very high solubility in acid solution, so that a clear, high-protein liquid
        with an acidic taste would result on dissolving the powder;

     sufficiently bland flavour of its own so that added flavouring can
        determine the taste of the drink; and

     demonstrated nutritive value because it is this that convinces athletes
        of performance-enhancing potential.

All of these had to be built into a process that could adjust to a natural raw material, fresh milk, that varies compositionally throughout the dairying season, and still continue to produce from it large quantities of whey protein isolate to the very tight specification under which it would have to be sold.