Explore the interaction mechanism between zein and EGCG using multi-spectroscopy and molecular dynamics simulation methods

To further extend the use of κ-carrageenan (κ-C) in real food systems (such as beverages), the understanding of gelation properties of κ-C with the presence of food ingredients is critical. The effects of xylitol and maltitol (up to 30 wt %) on the rheological and structural properties of κ-C were inspected by means of rheometer and Fourier transform infrared (FTIR). With the addition of xylitol, the gelation temperature increased from 44.1 to 57.3 °C, while the gelation temperature increased from 44.1 to 61.4 °C in maltitol systems. With the increasing concentration of both xylitol and maltitol, the values of fractal dimension df and complex modulus G* of κ-C increased, while the relaxation exponent n decreased from 0.87 to 0.39 of xylitol and 0.87 to 0.78 of maltitol, respectively. These indicated that the gel networks of aqueous κ-C were improved by the addition of xylitol and maltitol. The FTIR results showed that the interaction between κ-C and these polyols contributed to the increase of hydrogen bonds. The effects of maltitol on κ-C were stronger than those of xylitol because of more equatorial-OH bonds in maltitol. These findings contribute to a better understanding of the gelation processes of κ-C/polyols systems.

Section: Methodsmentioning

confidence: 99%

Xylitol and Maltitol Improve the Rheological Property of Kappa-Carrageenan

Huang

Mao

et al. 2021

“…Epigallocatechin gallate (EGCG) is a kind of polyphenol from tea. Recent studies have shown that EGCG has many excellent properties such as antitumor, antiradiation, and anti-oxidation capability [ 1 , 2 , 3 , 4 , 5 , 6 ]. However, EGCG is sensitive to neutral and alkaline solutions and becomes unstable as the oxygen concentration, temperature, and pH increases, resulting in impossible direct usage in these environments [ 7 , 8 , 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Encapsulation of EGCG by Zein-Gum Arabic Complex Nanoparticles and In Vitro Simulated Digestion of Complex Nanoparticles

Jin

Liu

Tong

et al. 2022

Epigallocatechin gallate (EGCG) has many excellent qualities such as its antitumor, antiradiation and anti-oxidation properties, but its application is limited because its oral bioavailability is low and stability is poor. In this paper, zein and gum arabic (GA) were used as wall materials to prepare Zein-GA complex nanoparticles for encapsulating and protecting the EGCG. The particle size of Zein-GA-EGCG complex nanoparticles ranged from 128.03–221.23 nm, and the EGCG encapsulation efficiency reached a maximum of 75.23% when the mass ratio of zein to GA was 1:1. The FTIR and XRD results illustrated that the components of the Zein-GA-EGCG complex nanoparticles interacted by electrostatic, hydrogen bonding, and hydrophobic interactions. The EGCG release rate of Zein-GA-EGCG nanoparticles (16.42%) was lower than that of Zein-EGCG (25.52%) during gastric digestion, and a large amount of EGCG was released during intestinal digestion, suggesting that the Zein-GA-EGCG nanoparticles could achieve the sustained release of EGCG during in vitro digestion. Hence, using Zein-GA complexes to encapsulate EGCG effectively increased the encapsulation efficiency of EGCG and realized the purpose of sustained release during simulated gastrointestinal digestion.

“…In the current study, the binding affinity energy value was −6.8 kcal/mol, which meant that EA had a potential active binding effect on zein. Compared with the binding affinity energy value in other studies, the one for zein and EA was smaller than around −4 kcal/mol for the interaction between zein and EGCG [ 49 ], but close to −7.7 kcal/mol for the interaction with curcumin [ 57 ]. This may be due to the higher hydrophobicity of EA and curcumin than EGCG.…”

Section: Resultsmentioning

confidence: 57%

“…Similarly, EGCG was stirred with zein solution, and the binding site number was about 1. This meant that only a single binding site was involved in the binding process [ 49 ].…”

Section: Resultsmentioning

confidence: 99%

Explore the Interaction between Ellagic Acid and Zein Using Multi-Spectroscopy Analysis and Molecular Docking

Zhao

Deng

Yan

et al. 2022

With the increasing interest in value-added maize products, the interaction of zein with bioactive molecules to become more nutritional and beneficial to human health has gained a lot of attention. To broaden the application of ellagic acid (EA) in maize flour products, we investigated the interaction between zein and EA. The fluorescence quenching type of zein interacting with EA was mainly static quenching through hydrophobic interaction, as demonstrated by quenching behavior modeling, and ultraviolet-visible spectroscopy confirmed the formation of zein–EA complexes. Synchronous fluorescence spectroscopy showed that EA reduced the polarity of zein around tyrosine residues, which were exposed to a more hydrophobic microenvironment. Meanwhile, circular dichroism suggested that EA noticeably changed the secondary structure of zein, which was mainly reflected in the increase of α-helix and β-sheet content and the decrease of random coil content. Finally, the molecular docking simulation found that zein could have five active sites binding to EA and there was hydrogen bond interaction besides hydrophobic interaction. The findings of this study provided a basis for a theory for the interaction mechanism between zein and EA, which could be essential for developing value-added plant-derived protein products using EA as a functional component.