Lower Diversity of Amylase-Trypsin Inhibitors and Ex Vivo-Released Opioid-Containing Peptides in Ancestral Compared to Modern Wheat Varieties Assessed by Proteomics and Peptidomics

This study focused on identifying amylase-trypsin inhibitors (ATIs) in seven Norwegian-cultivated wheat varieties, including common wheat and ancestral species, and identifying potentially harmful opioid peptides within the ex vivo digesta of these wheats. LC-MS/MS analysis of tryptic peptides from ATI fractions revealed that the common wheat variety Børsum exhibited the highest diversity of ATIs (n = 24), while they were less represented in tetraploid emmer (n = 11). Hexaploid wheat Bastian showed low diversity and relative abundance of ATIs. Nevertheless, digestion of Mirakel and Bastian by human gastrointestinal juices released the highest number of opioid-containing peptides, representing both gluten exorphins and gliadorphin. In conclusion, emmer had the lowest levels of ATIs, while einkorn and spelt released the fewest opioid-containing peptides after ex vivo digestion. These results point to the potential lower harmful effects of ancestral wheat compared to common hexaploid wheat varieties for wheat-sensitive individuals.