Impact of dairy protein powders on biscuit quality

The effects of whey protein concentrate and sodium caseinate (NaCas) on a short dough biscuit formulation were investigated with respect to dough characteristics and final product quality. Dairy powders were added at levels of 5, 10 and 15% of flour weight. Addition of 5 and 10% dairy protein powders reduced dough hardness. Doughs containing 10 and 15% NaCas had significantly higher springiness and cohesiveness values compared with the values of the control (p<0.05). Addition of both protein powders increased surface brownness, indicated by an increase in L * value. Whey protein concentrate resulted in biscuit shrinkage during baking, whereas biscuits containing NaCas powders were significantly larger than the control (p<0.05). In general, biscuits containing protein powders were harder than the control and hardness increased as the level of protein powder was increased. Confocal laser microscopy showed that doughs with NaCas had an extensive protein network and NaCas appears to interact with the flour proteins.