Debranning process to improve quality and safety of wheat and wheat products

The debranning process, essential technological step for removing the hulls in the case of covered cereals, is quite uncommon in “naked” grain processing. Nevertheless, numerous studies have been carried out on durum wheat varieties. These works thoroughly investigated the role of some technological parameters (processing time, hydration conditions of the kernels before processing, equipment scale, type of abrasive material) and the applicability also to samples with a high amount of starchy kernels. The results showed that this pre-milling operation was a useful tool for reducing the ash content and amylase activity of grains and, at the same time, increasing semolina yield of 3-4% points. These positive effects were obtained only taking care that the Debranning Level (DL %) (i.e. the amount of material removed from 100 g dried kernels) was lower than 10%. Pre-processing efficaciously reduced also the microbial contamination and the occurrence of DON, one of the mycotoxins more frequent in durum wheat. Thanks to the encouraging results obtained with durum wheat, attention is shifting to common wheat. At this regard, DiSTAM researchers have been working on industrial scale debranning, demonstrating that the process can be successfully applied to this cereal too, regardless of the hardness of the kernels. Also for common wheat was important to keep the DL lower than 10% in order to assure solely the elimination of bran layers, without loosing some endosperm materials (rich in starch) into the waste.