Soy is an important component of the human diet thanks to its nutritional value and high protein content; however, it also represents a risk for allergenic consumers due to its potential to trigger adverse reactions in sensitized individuals. The putative correlation between immunoreactivity and resistance to the human gastrointestinal (GI) digestion has drawn attention to investigating soybean proteins digestibility. In this work, we provided further insights into this field by performing in vitro simulated GI digestion experiments directly on ground soybean seeds, to provide more realistic results obtained from the digestion of the whole food matrix. Soybean digestion products were analyzed by SDS-PAGE followed by untargeted HPLC-MS/MS analysis and the final data were software treated to enable protein/peptide identification. The latter allowed monitoring the proteolytic degradation of the main soybean proteins during the gastric and duodenal phases. In particular, β-conglycinin and trypsin inhibitors showed the highest resistance to the combined activity of GI enzymes, showing a partial degradation at the end of the duodenal phase as ascertained by the strong electrophoretic bands displayed at 50 kDa and 20 kDa, respectively. Glycinin subunits also presented, even if to a lower extent, resistance to the complete proteolytic degradation, as demonstrated by polypeptide fragments with molecular weight lower than 20 kDa displayed in the gel at the end of duodenal digestion. In addition, by bioinformatics analysis it was demonstrated that the GI resistant fragments of the allergenic proteins, β-conglycinin and glycinin, retained in their primary structure linear epitopes potentially able to trigger an immunoreaction when exposed to the intestinal mucosa. Moreover, such resistant peptides also presented a structural homology with epitope sequences recognized in other legume species, presenting a potential risk of adverse cross-reaction for a larger category of allergic consumers.

Cow’s milk is considered the best wholesome supplement for children since it is highly enriched with micro and macro nutrients. Although the protein fraction is composed of more than 25 proteins, only a few of them are capable of triggering allergic reactions in sensitive consumers. The balance in protein composition plays an important role in the sensitization capacity of cow’s milk, and its modification can increase the immunological response in allergic patients. In particular, the heating treatments in the presence of a food matrix have demonstrated a decrease in the milk allergenicity and this has also proved to play a pivotal role in developing tolerance towards milk. In this paper we investigated the effect of thermal treatment like baking of cow’s milk proteins that were employed as ingredients in the preparation of muffins. A proteomic workflow was applied to the analysis of the protein bands highlighted along the SDS gel followed by western blot analyses with sera of milk allergic children in order to have deeper information on the impact of the heating on the epitopes and consequent IgE recognition. Our results show that incorporating milk in muffins might promote the formation of complex milk–food components and induce a modulation of the immunoreactivity towards milk allergens compared to milk baked in the oven at 180 °C for ten minutes. The interactions between milk proteins and food components during heating proved to play a role in the potential reduction of allergenicity as assessed by in vitro tests. This would help, in perspective, in designing strategies for improving milk tolerance in young patients affected from severe milk allergies.