In this study, the moderation-excess interaction of epigallocatechin gallate (EGCG) and calcium ions (Ca2+) to the gelation performance of transparent egg white protein (EWP) gel (EWG) was explored. The oxidation of EGCG introduced a yellowish-brown EWG, whereas the weakening of Ca2+ ionic bonds caused a notable reduction in the hardness of EWG, from 120.67 g to 73.57 g. Achieving the optimal EGCG-to-Ca2+ ratio in EWG conferred enhanced water-holding capacity to 86.98%, while an excess of EGCG attributed to the creation of a three-dimensional structure within the void "walls". The elevated presence of EGCG influenced the ionic bonds and hydrophobic interactions, thereby presenting a moderate-excess relationship with sulfhydryl and disulfide bonds, beta-sheet, and alpha-helical structures. Notably, EGCG reduced the digestibility of EWG to 50.06%, while concurrently fostering the creation of smaller particle sizes. This study provides a scientific basis for the controllable preparation and quality regulation of transparent EWG.

Amaranthus tricolor L. is a cultivated green vegetable, commonly known as amaranth, which is similar to spinach, broccoli, and cabbage. In the present study, we investigated the antioxidant and antimicrobial activities of the methanol extract and various fractions from A. tricolor. Results show that A. tricolor ethyl acetate (EtOAc) extract displayed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity (IC50=16.43±1.53 μg/ml), which was higher than that of the positive control, butyl hydroxy anisd (IC50=19.42±0.91 μg/ml). This extract had a reducing power of 2.743 at 0.5 mg/ml and significantly attenuated production of reactive oxygen species in a dose-dependent manner. Further bioassay-monitored fractionation of the EtOAc extract yielded two flavonoids, kaempferol (1) and quercetin (2), and one phenolic acid, gallic acid (3). We found that the antimicrobial activity of compound 3 (at a dose of 63 μg/mL) was superior to that of the tetracycline control (at a dose of 250 μg/mL) against Escherichia coli. Additionally, compounds 1 and 2 (at a dose of 63 μg/mL each) displayed higher activities against Penicillium oxalicum and Staphylococcus aureus than the control. These results suggest that A. tricolor extract may represent a promising nutraceutical source due to the antioxidant and antimicrobial properties of its phenolic compounds.

In this study, succinic anhydride (SA) and octenyl succinic anhydride (OSA) were used to modify the egg white protein (EWP), and acylated EWP was further prepared as a gel by adding NaOH and heat modification. The results showed that the acylation degree for the SA- and OSA-added groups reached 57.68% and 26.95%, respectively, and the average size, the absolute value of ζ-potential, increased significantly with SA and OSA addition, indicating that acylation improved the stability of EWP solution. Furthermore, the surface hydrophobicity increased for the SA-added group while decreasing for the OSA-added group, and the acylation process exposed the flexibility part of the protein molecule. Acylated EWP prepared gel (EWG) showed a translucent and slightly yellow appearance (except for the sol state of the OSA-added 1:50 group), the gel strength, water-holding capacity and rheological properties for SA-added EWG were remarkably reduced while OSA-added EWG improved apparently. Intermolecular forces analysis indicated that the addition of SA promoted the formation of disulfide bonds and strengthened proteins interactions while adding OSA weakened the interactions. Microstructural observations revealed a rougher gel network structure and weaker protein cross-linking in the gel prepared after the acylation of proteins. However, the high efficiency of SA and promotion of protein-molecule interactions were unable to counteract the negative effect of SA on the extension of the gel network structure, and the interaction between OSA expanded the formation of the gel network structure.

Xanthan gum (XG) was added to egg-white-gel-derived peptides to create complexes and stabilise nanoemulsion under high-pressure homogenisation. This procedure was performed to investigate the stabilisation of nano -emulsions by small-molecule peptides under alkaline conditions (pH 11.0). The emulsion stability, including ionic, temperature and storage stability, and lipid oxidation were explored. The inclusion of XG altered the spatial structure of the peptides, which created cross-linked entangled aggregates. Furthermore, the protein peptides forming complexes with XG following sonication and heat treatment were more stable. They exhibited higher absolute zeta-potential values, surface hydrophobicity, and lower interfacial tension. The emulsion stabilised by 2.0 mg/mL complexes at a pH of 11.0 revealed that the addition of XG enhanced the homogeneity of the nanoemulsion droplets, presenting a single high particle size peaks and absolute zeta-potential values. The surface -absorbed protein content and the concentrations of the emulsions stabilised by sonication and the heat-treated peptides and XG complexes were higher. Moreover, the fluorescence microscope observed a higher surface coverage thickness of the emulsion droplets, effectively preventing oil oxidation. The emulsion environmental stability measurements found that the prepared emulsions were sensitive to salt ions and stable to temperature. Together with heat-treated peptides and XG complexes, sonication-stabilised emulsions exhibited better stability during storage. This study advances the possibility of stabilising the nanoemulsions of small-molecule peptides under alkaline conditions.

Chinese water chestnut (CWC, Eleocharis dulcis (Burm.f.) Trin. ex Hensch.) is widely consumed in China and is valued for its medicinal properties. This study investigates different CWC extracts for their antioxidant and antiproliferative activities. The yield following methanol extraction (51.28%) was significantly higher than that of other solvents. Additionally, the methanol extract demonstrated a high total phenolic value of 306.34 +/- 6.89 mg gallic acid equivalent (GAE)/g and high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with an IC50 of 11.73 +/- 0.96 mu g/ml. The methanol extract remarkably suppressed proliferation of human cervical, lung, and colon cancer cell lines. Further investigation into the mechanism showed that the methanol extract inhibited colon cancer cell proliferation by inducing apoptosis. Bioassay-monitored fractionation of the methanol extract resulted in the isolation of three flavonoid compounds: quercetin, luteolin, and apigenin. Quercetin possessed the strongest antiproliferative activity on colon cancer cells, suggesting that CWC is a potential source of natural antioxidants and a potential cancer treatment.