EXTRUSION AND ROLL-COOKING OF CORN-SOY-WHEY MIXTURES

A partially demineralized, delactosed whey product containing about 36% protein and 56% lactose was used to supplement corn meal together with soy flour and soy isolate. All 4 mixtures prepared containing 75% corn meal. Mixtures A and B had 5% and 22% lactose-hydrolyzed whey respectively, mixture D, 5% unhydrolyzed whey and mixture C used skim milk as in CSM. Protein content was standardized to 20% protein. Amino acid analysis revealed an increase in all amino acids except leucine with respect to corn. Processing, either roll-cooking or extrusion reduced the quantity of essential amino acids. PER [protein efficiency ratio] values of all mixtures were not significantly different (P > 0.05) from casein. Functionally, the whey product reduces water absorption capacity but increases water and N solubility. Products from hydrolyzed whey, suitable for snacks or breakfast cereals, showed increased sweetness.