Color Changes and Available Lysine during Storage of Shelf‐Stable Concentrated Cheese Whey

Concentrated whey (about 50% solids) was stabilized against microbial deterioration by a combination of a slight reduction of water activity (a w ) (0.94 or 0.92), lowered pH (5.2 or 5.4) and addition of 0.2% potassium sorbate. Color changes and available lysine loss in the above shelf stable whey, stored at different temperatures, were studied. A zero order reaction kinetics was observed for color changes during browning of the concentrated whey; activation energy was found to be 26 Kcal/mole. The loss of available lysine amounted to 20–30% of the initial value after three months of storage at 30°C.