Conformational Changes in Wheat Gluten After using Ag-nanoparticles

Abstract

A b s t r a c t. Silver nanoparticles have antimicrobial properties since they can be regarded as an efficient protector against pathogenic microorganisms. Fourier transform infrared spectroscopy was used to examine conformational changes in the secondary structure of wheat gluten washed out from grain treated with an aqueous solution of silver nanoparticles stabilized by trisodium citrate. Silver nanoparticles were used as a protective layer on the grain surface against bacterial and fungal infections (antimicrobial agent). Analysis of the amide I band revealed significant changes in the secondary structure after using silver nanoparticles. An increase in the b-sheet content (from 36.2 to 39.2%) was observed at the expense of the a-helix and b-turn content. To find factors causing these changes, the wheat grains were treated by an aqueous solution of trisodium citrate and water. The results obtained indicate that the changes in the gluten structure were connected mainly with the trisodium citrate action due to presence of a small number of free molecules of the stabilizer in the solution of silver nanoparticles. Additionally, the conformational changes in gluten pointed out that gluten flexibility increased (decrease in the aH/bS ratio from 1.40 for the control sample to 1.26 for the silver nanoparticle-treated samples) as well as the solubility of gluten decreased (decrease in the b-turn content from 13.1 to 11.4%).K e y w o r d s: silver nanoparticles, trisodium citrate, wheat gluten, FTIR spectroscopy, secondary structure

Effect of dietary fibre waste originating from food production on the gluten structure in common wheat dough

“…The control sample contains 25% of the β-sheets (βS), 69% of the α-helices (αH) and 6% of the β-turns (βT). Similar secondary structures with similar location of the Gaussians were determined by Nawrocka (2014) in the native gluten. However, the contents of particular structures differed significantly (βS -36%, αH -51%, βT -13%).…”

Proporties and Synthesis of Biosilver Nanofilms for Antimicrobial Food Packaging

“…A peak at 1650 cm −1 is associated with α-helical and a random structure, and the shoulder at ≈1668 cm −1 is associated with β-turns and could also be related to glutamine side chains. The amide I region of the hydrated gluten protein broad shoulders was observed at 1654–1650 cm −1 , indicating α-helix conformation [ 19 , 20 , 21 , 22 , 23 , 24 ].…”

Effects of Altitudinal Gradient on Physicochemical and Rheological Potential of Quinoa Cultivars

“…The secondary structure of quinoa has not been well-studied by deconvolution spectroscopy. However, García-Parra et al (2021) and Roa-Acosta et al (2020) identified structures such as β-sheet, random coil, α-helix, β-turns, and β-type, between the bands 1,600 and 1,700 cm −1 , being able to change the intensity of the peaks of these structures because of the effects of genetic diversity, agro-industrial processing, or climatic factors during primary production, as manifested for other species (Nawrocka, 2013;Li et al, 2020;Pezzotti et al, 2021). Table 2 shows that the 1,547 and 1,634 cm −1 bands associated with amides II and I present a higher peak intensity in the cold and warm climates, responding to the influence generated by the environmental temperature and hydric status on the speed of gas exchange, transport of substances, and their discharge in storage organs; such a phenomenon is very variable in plants that present C3 metabolism (Sonnewald et al, 2020), because the stomatal opening determines the speed of multiple physiological activities and accumulation of proteins in the seeds.…”