Effects of Electrospun Potato Protein-Maltodextrin Mixtures and Thermal Glycation on Trypsin Inhibitor Activity

Fibers of potato protein and polysaccharides were obtained by needleless electrospinning. Mixtures of maltodextrin DE2 (dextrose equivalent) (0.8 g/mL), DE21 (0.1 g/mL), and different concentrations of potato protein (0.05, 0.1, 0.15, and 0.2 g/mL) were used for fiber production. Glycation was performed via the Maillard reaction after thermal treatment (0/6/12/24/48 h, 65 degrees C, 75% relative humidity). The effects of electrospinning and heating on trypsin inhibitor activity (IA) were studied. The results of the IA assay showed that electrospinning and glycation caused significant differences in IA among blends, heating times, and the interaction of blend and heating time (p < 0.001). The higher the protein content in the fibers, the higher the IA. The lowest IA was found in the mixture with the lowest protein content after 48 h. In other blends, the minimum IAs were found between 6 and 12 h of heating. The determination of the free lysine groups showed a nonsignificant decrease after heating. However, higher free lysine groups per protein (6.3-9.5 g/100 g) were found in unheated fibers than in the potato protein isolate (6.0 +/- 0.5 g/100 g). The amide I and amide II regions, detected by the Fourier transform infrared spectra, showed only a slight shift after heating.