INVESTIGATION OF BIOACTIVE PEPTIDES IN DIFFERENT KINDS OF BREAD USING IN SILICO AND IN VITRO DIGESTION APPROACH AND DETERMINATION OF THEIR BIOACTIVITIES
Project no. 20418 · Status: Kapanmış · 2018
Summary
Radical changes in societies with industrialization have directly affected their eating habits. Recently, bread and bakery products sector is one of the areas where new formulations have been developed with the use of ancient cereals such as einkorn wheat and pseudo cereals such as chia, quinoa and buckwheat. In parallel, the increase in the diversity of the types of bread and using different kinds of cereals in bread making has been drawing attention recently. From this point, within the scope of the master's thesis, the aim was the determination of bioactive peptides that will be released by applying in silico digestion to white bread and other bread varieties, determining the ACE inhibitory activities of the bioactive peptides that will be released by in vitro digestion and comparing the bioactivities obtained after both digestions. Sequences of the storage proteins belonging to cereal and pseudocereal varieties used in breads were obtained through the databases and bioactivities, allergenicity, and toxicities of the released peptides were investigated with the help of in silico tools that enable analysis with a bioinformatics approach. In the next part of the study, the changes in protein profiles of white bread, whole wheat bread, whole wheat, and chia bread, multigrain bread, multigrain, einkorn wheat and quinoa bread, and rye buckwheat bread before and after in vitro digestion were investigated. Following in vitro gastrointestinal digestion of the bread samples, the ACE inhibitory activities of the peptides whose molecular weights were below 3 kDa were determined. The common bioactivities determined after in silico digestion were identified as DPP IV inhibitory, ACE inhibitory and antioxidant activities. Among the proteins with high bioactive peptide frequencies buckwheat, quinoa, and oat proteins displayed the highest bioactivity potentials. Release of allergen peptides following in silico digestion of cereals and pseudocereals were determined and the allergenicity potentials of wheat, einkorn wheat and rye were the highest. In silico digestion caused the release of toxic peptides from the storage proteins of these cereals and maize. Protein profiles of the breads after in vitro digestion showed the release of peptides after in vitro digestion except for high molecular weight wheat glutenin which was resistant to the digestive enzymes. Whole wheat and chia bread (IC50 0.144 + 0.039 mg / mL protein) displayed the highest ACE inhibitory effect. However, compared to ACE inhibitor captopril (0.9 µg / mL) used as a positive control, this effect was considered as very low. In conclusion, it has been determined that the bread, which is a staple food in the dietary habit of Turkish people, has bioactive peptides that can inhibit the ACE enzyme associated with high blood pressure as a result of in vitro gastrointestinal digestion. As a result, despite the perception created today regarding the reduction of bread consumption or its complete removal from the diet, it can be said that in a healthy and balanced diet, the consumption of bread by considering the portion control will have a positive effect especially in the control of hypertension.