scholarly journals Towards Oxidatively Stable Emulsions Containing Iron-Loaded Liposomes: The Key Role of Phospholipid-to-Iron Ratio

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1293
Author(s):  
Alime Cengiz ◽  
Karin Schroën ◽  
Claire Berton-Carabin
Keyword(s):  
Oxidative Stability ◽  
Ferrous Sulfate ◽  
Iron Concentration ◽  
Egg Yolk ◽  
Antioxidant Effect ◽  
Crucial Importance ◽  
Fortified Foods ◽  
Oil In Water ◽  
Iron Concentrations

To encapsulate soluble iron, liposomes were prepared using unsaturated phospholipids (phosphatidylcholine from egg yolk), leading to high encapsulation efficiencies (82–99%). The iron concentration affected their oxidative stability: at 0.2 and 1 mM ferrous sulfate, the liposomes were stable, whereas at higher concentrations (10 and 48 mM), phospholipid oxidation was considerably higher. When applied in oil-in-water (O/W) emulsions, emulsions with liposomes containing low iron concentrations were much more stable to lipid oxidation than those added with liposomes containing higher iron concentrations, even though the overall iron concentration was similar (0.1 M). Iron-loaded liposomes thus have an antioxidant effect at high phospholipid-to-iron ratio, but act as pro-oxidants when this ratio is too low, most likely as a result of oxidation of the phospholipids themselves. This non-monotonic effect can be of crucial importance in the design of iron-fortified foods.

Role of Continuous Phase Protein on the Oxidative Stability of Fish Oil-in-Water Emulsions

2004 ◽  
Vol 52 (14) ◽  
pp. 4558-4564 ◽  
Author(s):  
Habibollah Faraji ◽  
D. Julian McClements ◽  
Eric A. Decker
Keyword(s):  
Fish Oil ◽  
Oxidative Stability ◽  
Continuous Phase ◽  
Oil In Water ◽  
Phase Protein

scholarly journals Lipid Oxidation in Emulsions Fortified with Iron-Loaded Alginate Beads

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 361 ◽  
Author(s):  
Alime Cengiz ◽  
Karin Schroën ◽  
Claire Berton-Carabin
Keyword(s):  
Lipid Oxidation ◽  
Ferrous Sulfate ◽  
Continuous Phase ◽  
Alginate Beads ◽  
Reactive Iron ◽  
Fortified Food ◽  
Starting Point ◽  
Oil In Water ◽  
Potential Use

The potential use of iron-loaded alginate beads to fortify oil-in-water (O/W) emulsions was studied. Iron-loaded alginate beads with different sizes (0.65, 0.84, 1.5 and 2 mm) were produced by ionic gelation with calcium chloride, leading to 81% encapsulation efficiency (EE) of ferrous sulfate. These beads were added to O/W emulsions to investigate their effect on lipid oxidation. The use of iron-loaded alginate beads inhibited lipid oxidation in emulsions, compared to a control emulsion with the same concentration of free ferrous sulfate in the continuous phase, but did not totally prevent it. Results obtained with scanning electron microscopy and energy dispersive X-ray spectroscopy (EDX) analysis showed that some reactive iron was present at the surface of the beads. Oxidation of the lipid droplets was slightly higher for smaller alginate beads, suggesting that the reaction could be linked to the total bead surface. When covering iron-loaded beads with an extra layer of alginate, lipid oxidation was inhibited, which confirmed the role of reactive surface-bound iron. This study shows that the location of iron within the encapsulates plays a crucial role in the chemical stability of fortified foods and should be taken as a starting point in the design of iron-fortified food products.

Assessment of Pomegranate Juice as Antioxidant in Extender on Cauda Epididymis Spermatozoal Quality of Buck at Refrigerated Temperature

2019 ◽  
Vol 15 (02) ◽  
pp. 26-29
Author(s):  
Amarjeet Amarjeet ◽  
C T Khasatiya ◽  
L Chaudhary
Keyword(s):  
Detrimental Effect ◽  
Egg Yolk ◽  
Antioxidant Effect ◽  
Pomegranate Juice ◽  
Antioxidant Additive ◽  
Epididymal Spermatozoa ◽  
The Dead

The present investigation was carried out to study the refrigeration preservation of the cauda epididymal retrieved spermatozoa of buck in Tris egg yolk citrate (TEYC) dilutor containing pomegranate juice as antioxidant additive. The retrieved cauda epididymal spermatozoa extended in TEYC dilutor were studied in five groups by adding different concentration of pomegranate juice as additive (0% as control T1 group and 5%, 10%, 15% and 20% as treatment T2, T3, T4 and T5 groups, respectively) and storing at refrigerated temperature up to 48 hr. The results showed that the control extender had the least dead, abnormal and HOS non-reacted sperm percent among all treatments tested and that with increasing the pomegranate juice concentration in dilutor, the percentage of the dead, abnormal and HOST non-reacted spermatozoa increased significantly. The same trend was observed at all 12 hourly storage intervals indicating its detrimental effect on epididymal sperms of bucks at refrigeration temperature. The dead, abnormal, and HOST non-reacted sperm were significantly and positively interrelated with each other (r = 0.53-0.83). It was concluded that the inclusion of pomegranate juice in TEYC dilutor did not show any beneficial/antioxidant effect on epididymal sperms of buck in fresh or refrigerated semen and in fact all the levels of pomegranate juice (5% to 20%) were detrimental to cauda epididymal spermatozoa of a buck.

scholarly journals Influence of Whey Protein Micro-Gel Particles and Whey Protein Micro-Gel Particles-Xanthan Gum Complexes on the Stability of O/W Emulsions

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2301
Author(s):  
Man Zhang ◽  
Bin Liang ◽  
Hongjun He ◽  
Changjian Ji ◽  
Tingting Cui ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Whey Protein ◽  
High Speed ◽  
Xanthan Gum ◽  
Physical Stability ◽  
Theoretical Support ◽  
Gel Particles ◽  
Oil In Water ◽  
The Stability ◽  
The Impact

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

scholarly journals Plant Carotenoids as Pigment Sources in Laying Hen Diets: Effect on Yolk Color, Carotenoid Content, Oxidative Stability and Sensory Properties of Eggs

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 721
Author(s):  
Kristina Kljak ◽  
Klaudija Carović-Stanko ◽  
Ivica Kos ◽  
Zlatko Janječić ◽  
Goran Kiš ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Egg Yolk ◽  
Sensory Properties ◽  
Carotenoid Content ◽  
Total Carotenoid ◽  
Plant Parts ◽  
Total Carotenoid Content ◽  
Dietary Content ◽  
Sensory Color ◽  
Carotenoid Profile

The aim of this study was to evaluate the effect of a supplementation diet for hens consisting of dried basil herb and flowers of calendula and dandelion for color, carotenoid content, iron-induced oxidative stability, and sensory properties of egg yolk compared with commercial pigment (control) and marigold flower. The plant parts were supplemented in diets at two levels: 1% and 3%. In response to dietary content, yolks from all diets differed in carotenoid profile (p < 0.001). The 3% supplementation level resulted in a similar total carotenoid content as the control (21.25 vs. 21.79 μg/g), but by 3-fold lower compared to the 3% marigold (66.95 μg/g). The tested plants did not achieve yolk color fan values as the control (13.47) or 3% marigold (11.47), and among them, calendula had the highest values (9.73). Despite the low carotenoid content in diets supplemented with basil herb, iron-induced malondialdehyde (MDA) concentration was low as for marigold (on average 106.83 vs. 92.68 ng/g after 250 min). The treatments differed in sensory color scores for fresh and hard-boiled yolks and flavor while other sensory properties were similar. In conclusion, the supplementation of plants in a hen diet may result in yolks containing carotenoids and other compounds showing a high antioxidant effect.

scholarly journals Positive Regulation of fur Gene Expression via Direct Interaction of Fur in a Pathogenic Bacterium, Vibrio vulnificus

2007 ◽  
Vol 189 (7) ◽  
pp. 2629-2636 ◽  
Author(s):  
Hyun-Jung Lee ◽  
So Hyun Bang ◽  
Kyu-Ho Lee ◽  
Soon-Jung Park
Keyword(s):  
Gene Expression ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
Iron Concentration ◽  
Direct Interaction ◽  
Repeated Sequence ◽  
Upstream Region ◽  
Fur Protein

ABSTRACT In pathogenic bacteria, the ability to acquire iron, which is mainly regulated by the ferric uptake regulator (Fur), is essential to maintain growth as well as its virulence. In Vibrio vulnificus, a human pathogen causing gastroenteritis and septicemia, fur gene expression is positively regulated by Fur when the iron concentration is limited (H.-J. Lee et al., J. Bacteriol. 185:5891-5896, 2003). Footprinting analysis revealed that an upstream region of the fur gene was protected by the Fur protein from DNase I under iron-depleted conditions. The protected region, from −142 to −106 relative to the transcription start site of the fur gene, contains distinct AT-rich repeats. Mutagenesis of this repeated sequence resulted in abolishment of binding by Fur. To confirm the role of this cis-acting element in Fur-mediated control of its own gene in vivo, fur expression was monitored in V. vulnificus strains using a transcriptional fusion containing the mutagenized Fur-binding site (fur mt::luxAB). Expression of fur mt::luxAB showed that it was not regulated by Fur and was not influenced by iron concentration. Therefore, this study demonstrates that V. vulnificus Fur acts as a positive regulator under iron-limited conditions by direct interaction with the fur upstream region.

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