Comparative Study on Foaming Properties of Egg White with Yolk Fractions and Their Hydrolysates

As an excellent foaming agent, egg white protein (EWP) is always contaminated by egg yolk in the industrial processing, therefore, decreasing its foaming properties. The aim of this study was to simulate the industrial EWP (egg white protein with 0.5% w/w of egg yolk) and characterize their foaming and structural properties when hydrolyzed by two types of esterase (lipase and phospholipase A2). Results showed that egg yolk plasma might have been the main fraction, which led to the poor foaming properties of the contaminated egg white protein compared with egg yolk granules. After hydrolyzation, both foamability and foam stability of investigated systems thereof (egg white protein with egg yolk, egg white protein with egg yolk plasma, and egg white protein with egg yolk granules) increased significantly compared with unhydrolyzed ones. However, phospholipids A2 (PLP) seemed to be more effective on increasing their foaming properties as compared to those systems hydrolyzed by lipase (LP). The schematic diagrams of yolk fractions were proposed to explain the aggregation and dispersed behavior exposed in their changes of structures after hydrolysis, suggesting the aggregated effects of LP on yolk plasma and destructive effects of PLP on yolk granules, which may directly influence their foaming properties.

Comparing Glycerol with Dimethylformamide and Combination for Cryopreservation of Pug Dog Semen in Egg Yolk Plasma Containing Extender

Background: In order to find an alternative cryoprotectant for canine semen, different cryoprotectants, as dimethyl sulphoxide and ethylene glycol, dimethyle formamide either alone or in combination with glycerol have been evaluated on pooled semen of different breeds with different opinions. Methods: In the current study the effect of glycerol, DMF and their combination in Tris-citric acid-fructose egg yolk plasma extender on motility, viability, plasma membrane integrity (PMI), acrosome integrity (AI), inner mitochondrial membrane potential (IMMP), reactive oxygen species (ROS) and antioxidant enzymes in frozen-thaw semen of pug breed was compared. Result: Values for motility, viability, (PMI), AI were significantly (p less than 0.05) high in TCFEYP-G compared to TCFEYP-DMF and TCFEYP-G+DMF at post thaw. However, HIMMP and MIMMP/MDA were non-significantly (P greater than 0.05) high and low in TCFEYP-G compared to TCFEYP-DMF and TCFEYP- G + DMF at post thaw, respectively. MDA concentration was significantly (p less than 0.05) low in TCFEYP-G compared to TCFEYP-DMF and TCFEYP-G + TCFEYP-DMF extenders. However, H2O2, scavenging capacity of spermatozoa, cryopreserved in TCFEYP-G was significantly (p less than 0.05) higher than in TCFEYP-DMF and TCFEYP-G + TCFEYP-DMF. However, there was no significant (p greater than 0.05) difference in superoxide free radical scavenging activity and nitrite concentration of spermatozoa among the three extenders. Activity of GPX, SOD and Catalase was also significantly (p less than 0.05) higher in TCFEYP-G compared to TCFEYP-DMF and TCFEYP-G+DMF. However, values were reverse for GRE activity. This study concludes that glycerol is a healthier cryoprotectant to protect canine spermatozoa from cryo-injury during freezing-thawing process.

3D Cell Culture of Human Salivary Glands Using Nature-Inspired Functional Biomaterials: The Egg Yolk Plasma and Egg White

The egg yolk plasma (EYP)—a translucent fraction of the egg yolk (EY) obtained by centrifugation—was tested as a developmentally encouraging, cost-effective, biomaterial for salivary gland (SG) tissue engineering. To find optimal incubating conditions for both the human NS-SV-AC SG acinar cell line and SG fibroblasts, cells were stained with Live/Dead®. The cellular contents of 96-well plates were analyzed by high content screening image analysis. Characteristically, the EYP biomaterial had lipid and protein content resembling the EY. On its own, the EYP was non-conducive to cell survival. EYP’s pH of 6 mainly contributed to cell death. This was demonstrated by titrating EYP’s pH with different concentrations of either commercial cell culture media, NaOH, or egg white (EW). These additives improved SG mesenchymal and epithelial cell survival. The best combinations were EYP diluted with (1) 70% commercial medium, (2) 0.02 M NaOH, or (3) 50% EW. Importantly, commercial medium-free growth was obtained with EYP + NaOH or EYP + EW. Furthermore, 3D cultures were obtained as a result of EW’s gelatinous properties. Here, the isolation, characterization, and optimization of three EYP-based biomaterial combinations are shown; two were free of commercial medium or supplements and supported both SG cells’ survival.

3D Cultures of Salivary Gland Cells in Native or Gelled Egg Yolk Plasma, Combined with Egg White and 3D-Printing of Gelled Egg Yolk Plasma

For salivary gland (SG) tissue engineering, we cultured acinar NS-SV-AC cell line or primary SG fibroblasts for 14 days in avian egg yolk plasma (EYP). Media or egg white (EW) supplemented the cultures as they grew in 3D-Cryo histology well inserts. In the second half of this manuscript, we measured EYP’s freeze-thaw gelation and freeze-thaw induced gelled EYP (GEYP), and designed and tested further GEYP tissue engineering applications. With a 3D-Cryo well insert, we tested GEYP as a structural support for 3D cell culture or as a bio-ink for 3D-Bioprinting fluorescent cells. In non-printed EYP + EW or GEYP + EW cultures, sagittal sections of the cultures showed cells remaining above the well’s base. Ki-67 expression was lacking for fibroblasts, contrasting NS-SV-AC’s constant expression. Rheological viscoelastic measurements of GEYP at 37 °C on seven different freezing periods showed constant increase from 0 in mean storage and loss moduli, to 320 Pa and 120 Pa, respectively, after 30 days. We successfully 3D-printed GEYP with controlled geometries. We manually extruded GEYP bio-ink with fluorescence cells into a 3D-Cryo well insert and showed cell positioning. The 3D-Cryo well inserts reveal information on cells in EYP and we demonstrated GEYP cell culture and 3D-printing applications.