Molecular properties of whole wheat pasta: role of semolina quality and processing

Whole wheat pasta is not only a source of proteins and carbohydrates, but provides consumers with a staple food intrinsically rich in fiber and phenolics. Not many studies tackled the complexity of the protein pattern in whole wheat semolina and their interaction with bioactives before and after processing. This study applies a multidisciplinary approach to investigate at the molecular level the relationship between product structure and biological functionality. Pasta was produced in a pilot plant from whole wheat semolina with different protein content (12% and 15%) using either low (55°C)­ and high (85°C)­temperature drying diagrams. The antioxidant capacity and the profile of both free and bound phenolic compounds in the raw materials were similar, mainly formed by flavonoids. The starch gelatinization kinetics is slightly different in raw materials, likely due to a different water distribution among phases. Proteins in the two raw materials share a similar macromolecular organization, if not for a very different distribution of hydrophobic patches on the protein surface. The drying diagram had a significant impact on the aggregation state of proteins and antioxidant compounds. High­temperature drying promoted thermal coagulation of proteins by covalent (disulfide) cross­linking. High­temperature drying also slightly affected phenolic composition and deeply increased the antioxidant capacities. In order to ascertain the impact of the drying diagram on the bioavailability of phenolics and their anti­inflammatory activity, the digestate from in vitro digestion is being utilized to study various responses in a cultured intestinal cell model. These experiments are currently underway. This study is part of the Italian PRIN 2020 project (Grant Number 2022SCYHWK)