Effects of casein hydrolysate prepared with savinase on the quality of breads made by frozen dough

The effect of casein savinase hydrolysate (CSH) usage on frozen dough (1%, 1.5% and 2%, g/100 g flour) was investigated in terms of rheological, thermal, structural characteristics of wheat doughs and the textural and color properties of corresponding breads. Rheological measurement showed that CSH addition into dough led to a reduction of Gʹ and Gʹʹ values, but a similar trend wasn’t observed in frozen dough samples. The increase of protein band intensity was observed for control dough (CD) after frozen storage (-30 °C, 28 days) while there was no increases in band intensities of the doughs with CSH. The freezable water content of unfrozen doughs was decreased gradually with addition of CSH depended on concentration level. Frozen storage caused a notable reduction in α-helices structure of CD sample (p<0.05) while no significant variation was observed for the doughs containing CSH (p>0.05). Lowest specific volume reduction and hardness increment were observed for the breads containing 1.5% and 2% CSH. Frozen storage caused a significant reduction on b* value of bread crust (p<0.05) while no significant effect was observed for L* and a* value during frozen storage (p > 0.05). Overall, CSH incorporation into frozen dough can be an alternative that could reduce the quality deteriorations of frozen bread.