Evaluation of gliadins-diglycosylated cyanidins interaction from litchi pericarp through ultraviolet and fluorescence measurements

Effects of purple cabbage anthocyanin extract on the gluten characteristics and the gluten network evolution of high-gluten dough

BACKGROUND

Anthocyanins are polyphenolic pigments that have hypoglycemic, antioxidation, anti-aging, and other effects. Research has shown that polyphenols can optimize the processing of dough and improve the texture and nutritional characteristics of dough products. The formation of gluten networks is decisive for the quality of flour products. The effects of purple cabbage anthocyanin (PCA) extract on the structure, microscopic morphology, and network formation of gluten protein were studied, and the types of cross-linking between PCA and gluten protein are discussed.

RESULTS

The results show that PCA extract increased the free sulfhydryl (SH) group content and the free amino group of gluten proteins, stimulated an increase in the β-sheet ratio and the decrease of α-helix ratio, and increased the gluten index significantly (P < 0.05). The PCA extract also induced gluten protein aggregation, increased the height of protein molecular chains, and stimulated the formation of gluten networks. When PCA extract concentrations were 4 g kg-1 and 8 g kg-1, the gluten network was more homogeneous, continuous, and dense.

CONCLUSION

Appropriate anthocyanins have a positive effect on the properties of gluten and promote the formation of gluten networks. Excessive anthocyanins destroy gluten protein interaction and harm gluten cross-linking. This study may provide a useful source of data for the production of functional flour products rich in anthocyanins. © 2024 Society of Chemical Industry.

Extraction, identification and application of gliadin from gluten: Impact of pH on physicochemical properties of unloaded- and lutein-loaded gliadin nanoparticles

In the present study, high purity gliadin was extracted from gluten by the marginally modified Osborne method and the effect of different pHs in the aqueous ethanol on the physicochemical properties of unloaded gliadin nanoparticles (UGNs) and lutein-loaded gliadin nanoparticles (LGNs) was investigated. The results revealed that the formation of UGNs and LGNs at diverse pHs was driven by a conjunction of hydrogen bonding, electrostatic interactions and hydrophobic effects, but their dominant roles varied at different pHs. pH also significantly impacted the surface hydrophobicity, secondary structure and aromatic amino acid microenvironment of UGNs and LGNs. LGNs at pH 5.0 and at pH 9.0 exhibited better loading capacity and could reach 9.7884 ± 0.0006 % and 9.7360 ± 0.0017 %, respectively. These two samples also had greater photostability and thermal stability. Half-lives of LGNs at pH 5.0 were 2.185 h and 54.579 h, respectively. Half-lives of LGNs at pH 9.0 were 2.937 h and 49.159 h, respectively. LGNs at pH 5.0 and LGNs at pH 9.0 also had higher bioaccessibility of lutein, with 15.98 ± 0.04 % and 15.27 ± 0.03 %, respectively. These findings yielded precious inspirations for designing innovative lutein delivery system.

Molecular dynamics simulation for mechanism revelation of the safety and nutrition of lipids and derivatives in food: State of the art

Molecular dynamics (MD) simulation has proved to be a powerful tool in the study of proteins, nucleic acids, lipids, and carbohydrates et al. in fields of health, nutrition, and food science. In particular, MD simulation has been employed in the investigation of various lipid systems such as triglycerides, phospholipid membranes, etc. Due to the continuous updating of computing resources and the development of new MD simulation methods and force field parameters, the simulation's time and size scale of lipids system has increased by several orders of magnitude. However, MD simulation cannot be used for systems invovle chemical reactions. These greatly limit its further application in the field of lipid research. This paper reviews the progress and development of MD simulation, especially for the application of MD simulation in different lipid systems. In this paper, MD simulation and its general workflow was briefly introduced firstly. Subsequently, the application of MD simulation in various lipid systems was reviewed in-depth. Finally, the limitation and future prospects of MD simulation in lipid research were also discussed. This review provided new insights into the investigation of MD simulation, and a novel thought for lipid study. We believe that MD simulation will exhibit more and more great advantages in the investigation of lipids in the future due to the development of novlel methods.

New insights into red plant pigments: more than just natural colorants

Pigments make nature both colorful and attractive. Humans have always incorporated the natural pigments of fruits, vegetables and spices into their dietary requirements. Naturally occurring red pigments in plants are carotenoids, anthocyanins and betacyanins. Natural pigments, apart from colour, provide added properties and are therefore considered to be bioactive constituents. Red natural colorants are one of the most widely used in the food industry. The interest in these pigments lies in the enhancement of the healthy effects of the diet. In this context, attention is given to carotenoids, anthocyanins and betacyanins, with emphasis on the basic chemical and biochemical attributes and wide-ranging health-promoting benefits of these pigments. Thus, in this review, we systematically present the advantages and limitations of these natural pigments as food colorants in relation to their physico-chemical properties, reactivity and bioactivity.

Transport of Flavanolic Monomers and Procyanidin Dimer A2 across Human Adenocarcinoma Stomach Cells (MKN-28)

It has been proven that A-type procyanidins, containing an additional ether bond, compared to B-type procyanidins are also bioavailable in vitro and in vivo. However, their bioavailability and absorption in the gastrointestinal tract remain uncertain. In this study, a model of the human adenocarcinoma stomach cell line (MKN-28) was established to explore the cellular transport of flavanolic monomers and procyanidin dimer A2, which were isolated from the litchi pericarp extract. After the integrity and permeability of the cell monolayer were ensured by measurement of the transepithelial electrical resistance and the apparent permeability coefficient for Lucifer yellow, the transportation of procyanidins A2 and B2, (-)-epicatechin (EC), and (+)-catechin (CC) was studied at pH 3.0, 5.0, or 7.0 in the apical side, with compound concentrations of 0.05 and 0.1 mg/mL based on the cytotoxicity test. High-performance liquid chromatography and liquid chromatography-mass spectrometry analyses indicated that EC, CC, and A2 were transported in the MKN-28 cell line from 30 to 180 min, while B2 showed no transport. The maximal transport efficiencies of EC, CC, and A2 were 23 ± 0.81, 13.16 ± 1.53, and 16.41 ± 1.36%, respectively, existing at 120, 180, and 120 min of transportation. Laser scanning confocal microscopy analysis presented the dynamic transmission of EC, in accordance with the result of concentration determination, suggesting that the A-type procyanidins are possibly absorbed through the stomach barrier, which is pH- and time-dependent.

Increasing Yield and Antioxidative Performance of Litchi Pericarp Procyanidins in Baked Food by Ultrasound-Assisted Extraction Coupled with Enzymatic Treatment

Extraction with organic solvents is a traditional method to isolate bioactive compounds, which is energy-wasting and time-consuming. Therefore, enzyme and ultrasound treatments were combined to assist the extraction of oligomeric procyanidins from litchi pericarp (LPOPC), as an innovative approach to replace conventional extraction methods. Under optimum conditions (enzyme concentration 0.12 mg/mL, ultrasonic power 300 W, ultrasonic time 80 min, and liquid/solid ratio 10 mL/g), the yield of LPOPC could be improved up to 13.5%. HPLC analysis indicated that the oligomeric procyanidins (OPC) content of LPOPC from proposed extraction was up to 89.6%, mainly including (-)-epicatechin, procyanidin A1, A2, and A-type procyanidin trimer. Moreover, LPOPC powder was added in baked food to inhibit the lipid peroxidation. It was found that 0.2% (w/w) of LPOPC could maintain the quality of cookies in the first 7 days, by decreasing the peroxide values. The procyanidin dimers and trimers in LPOPC played more important roles as antioxidants compared to monomers during storage. The results also showed that the combined extraction process can be considered as a useful and efficient method for the extraction of functional components from other plant sources.