5. Conclusions
We studied the influence of the presence of starch on wheatgluten hydrolysis. Wheat gluten in wheatflour (WFG) was hydro-lyzed at 5.6 times higher solid concentrations but at the sameprotein concentrations than vital wheat gluten (VWG). WFG hy-drolysis at 40% solids resulted in higher DH% than VWG hydrolysisat 7.2% solids. Furthermore, higher DH% were obtained when hy-drolyzing VWG with added starch, compared to VWG alone and forWFG hydrolysis compared to the washed gluten fraction of thewheatflour. This showed that differences in the gluten composition and the presence of albumins and globulins in wheat flour cannotexplain the difference in DH%. Instead, we concluded that starchgranules facilitated the hydrolysis reaction by hindering the gluten aggregation. The final composition of the hydrolysates, though, wasjust a function of the enzyme used and the DH%, but not influencedby the starch. At higher solid concentrations up to 70% wheatflour,the positive effect of starch disappeared, because WFG hydrolysiswas hindered by mass transfer limitations and lower wateractivities.The results show that the understanding and prevention ofwheat gluten aggregation is important in order to improve wheatgluten hydrolysis, and could be a drive for mixer design or the useof additives other than starch.