Assessing the effect of traditional hulled wheat processing on bioactive compounds retention

Glume removal is the preliminary operation to make hulled wheats suitable to human consumption. Traditionally glumes are separated from kernels by means of stone mills, simultaneously causing kernel crushing, a loss of kernel parts and associated phytochemicals. The aim of this study was to compare bioactive compound retention of hulled wheat products obtained by traditional processing still used in Turkey and Armenia, with a more update plant located in Italy. On-plant samplings were carried out in two einkorn wheat bulgur processing plants in Turkey, and one emmer wheat processing plant, in Armenia and Italy. Whole and crushed kernels sampled at different processing stages were analysed for their phytochemical compound content. For the Italian plant, also the pearling process was considered. Whole kernels showed higher contents of lipid and phytochemical compounds than the correspondent processed fractions, with special respect for tocopherols and phytosterols. Carotenoid content was mainly affected by genotype. Pearling had a lower effect on the content of phytochemicals; however the correspondent waste fraction showed very high amounts of lipids and other compounds. All the plants showed similar retention of phytochemicals upon processing, with higher losses occurring in smaller kernel crushed fractions, mainly because of the loss of the germ.