Investigating the Links between Lower Iron Status in Pregnancy and Respiratory Disease in Offspring Using Murine Models.

Maternal iron deficiency occurs in 40-50% of all pregnancies and is associated with an increased risk of respiratory disease and asthma in children. We used murine models to examine the effects of lower iron status during pregnancy on lung function, inflammation and structure, as well as its contribution to increased severity of asthma in the offspring. A low iron diet during pregnancy impairs lung function, increases airway inflammation, and alters lung structure in the absence and presence of experimental asthma. A low iron diet during pregnancy further increases these major disease features in offspring with experimental asthma. Importantly, a low iron diet increases neutrophilic inflammation, which is indicative of more severe disease, in asthma. Together, our data demonstrate that lower dietary iron and systemic deficiency during pregnancy can lead to physiological, immunological and anatomical changes in the lungs and airways of offspring that predispose to greater susceptibility to respiratory disease. These findings suggest that correcting iron deficiency in pregnancy using iron supplements may play an important role in preventing or reducing the severity of respiratory disease in offspring. They also highlight the utility of experimental models for understanding how iron status in pregnancy affects disease outcomes in offspring and provide a means for testing the efficacy of different iron supplements for preventing disease.

Dietary egg white protein hydrolysate improves orotic acid-induced fatty liver in rats by promoting hepatic phospholipid synthesis and microsomal triglyceride transfer protein expression.

We investigated the effects of egg white protein hydrolysates (EWH) on orotic acid (OA)-induced nonalcoholic fatty liver (NAFL) in rats. Effects of the egg white protein (EWP) and EWH were also compared. Four groups of male Sprague-Dawley rats were separately fed AIN-76-based diets, supplemented with 20% casein for control, or with 1% OA, together with either 20% casein (OA), 20% EWP, or 20% EWH, respectively, for 3 d (developing stage) and 14 d (developed stage). In both feeding periods, animals from the OA group showed higher accumulation hepatic triacylglycerol (TAG) compared with those from the control group. In the 14-d experiment, dietary EWP and EWH significantly reduced the hepatic TAG levels. Intake of EWP reduced liver fat in OA-fed rats by 61%, while EWH reduced it by 92%. In addition, EWH restored the OA-induced high serum-TAG level to that seen in the control group. The 3 d experiment showed that consumption of EWH improved the expression of hepatic MTP, that was reduced by OA, without changing Mttp gene expression. It also increased the hepatic synthesis of PC and PE by enhancing the transcription of Pcyt1 and Pemt genes. Inclusion of EWP and EWH in the diet improves the OA-induced NAFL. EWH reduces the liver TAG better than EWP, and works more rapidly. Dietary EWH ameliorates OA-induced NAFL by promoting the secretion of hepatic TAG.

Evaluating the effect of cooking and gastrointestinal digestion in modulating the bio-accessibility of different bioactive compounds of eggs.

Eggs' nutritional value has been enhanced by enriching hen's diet with bioactive compounds, but factors influencing bio-accessibility are unspecified. This study investigated the effect of hen breed, diet enrichment, and cooking methods in modulating the egg compounds' bio-accessibility after gastrointestinal (GI) digestion. White Leghorn (WLH) and Rhode Island Red (RIR) hens were fed a corn-soybean-based diet enriched with flaxseed and carotenoids; eggs were collected, cooked, and subjected to simulated GI digestion. The results showed that egg proteins were equally digestible with no change in the degree of hydrolysis (DH). The linolenic fatty acid in enriched-cooked samples remained bio-accessible after GI digestion. The lutein bio-accessibility in enriched eggs decreased after GI digestion except in RIR fried sample. Eggs from WLH and RIR achieved similar peptide content after GI digestion. These results elucidate the bio-accessibility of different bioactive compounds in cooked eggs and the use of eggs as potential functional foods.

Improvement of the sensitivity of the detection of Gal d 6-specific IgE via biotinylation in vivo.

INTRODUCTION AND OBJECTIVES: This study aimed to compare the effects of different biotinylation methods on the performance characteristics of allergen-specific IgE detection. MATERIALS AND METHODS: The Gal d 6 gene was cloned into the pAN6/pAC6 vector, resulting in rGal d 6-Bio/Bio-rGal d 6 vector. The fusion protein was expressed in Escherichia coli AVB101 and simultaneously biotinylated in a site-specific manner. The Gal d 6 gene was amplified via PCR and cloned into the pET-28a vector and transformed into E. coli BL21 and purified via Ni-NTA, followed by chemical biotinylation using Sulfo-NHS-LC-Biotin. Twenty-eight patients allergic to hen's egg white were examined for sensitization against egg yolk. An antigen-capture enzyme-linked immunosorbent assay (AC-ELISA) was developed to detect allergen-specific IgE. RESULTS: rGal d 6, Bio-rGal d 6, and rGal d 6 were prepared using different biotin binding modes to detect allergen-specific IgE. rGal d 6-Bio (Kd=0.6154) and Bio-rGal d 6 (Kd=0.6698) had a markedly better detection performance than rGal d 6 (Kd=28.93), and the rGal d 6-Bio had a better detection performance in small-volume serum samples. CONCLUSIONS: rGal d 6-Bio improved the sensitivity for the detection of allergen-specific IgE.

Changes in physicochemical properties, gel structure and in vitro digestion of marinated egg white gel during braising.

In this paper, changes in physicochemical properties, gel structure and in vitro digestion of marinated egg with spice or tea during braising were investigated. Results indicated that the moisture content and surface hydrophobicity of marinated egg white showed an overall decreased trend. The springiness of marinated egg white showed an increased trend, and the hardness in the late stage showed an increased trend. Microstructure showed that compact gel structures formed many holes during the braising. Intermolecular forces showed that ionic bonds and disulfide bonds played a dominant role in the marinated egg white. Secondary structure showed that the ß-turn showed a decreased trend, contrary to that of random coils and α-helices. Appropriate braising increased the digestibility of marinated egg white, but excessively long-time braising could reduce it. Both spice and tea braising could improve the gel strength of protein, and the tea braising was also slightly better than spice braising.

The pattern of peptides released from dairy and egg proteins is highly dependent on the simulated digestion scenario.

Evaluating the gastrointestinal (GI) fate of proteins is part of the assessment to determine whether proteins are safe to consume. In vitro digestion tests are often used for screening purposes in the evaluation of potential allergenicity. However, the current pepsin resistant test used by the European Food Safety Authority, only corresponds to fasted gastric conditions representative of a late phase adult stomach. In addition, these tests are performed on isolated proteins and the effect of the food matrix and processing are not systematically considered. The aim of this research is to compare three different static in vitro GI scenarios that are physiologically relevant. Namely, an infant, early phase (fed state) adult and late phase (fasted state) adult model. These protocols are applied to well-characterised isolated dairy (ß-lactoglobulin and ß-casein) and egg (lysozyme and ovalbumin) proteins and the impact of food matrix/processing on their proteolysis is also investigated. A combination of SDS-PAGE, LC-MS/MS and spectrophotometric assay was used for the evaluation of the proteolysis. Results highlight differences across the three GI scenarios whether on isolated proteins or within food matrices. The infant model led to incomplete digestion, leaving intact egg proteins, either isolated or in the food matrix, and intact ß-lactoglobulin in the milk. In addition, peptides greater than 9 amino acids were found throughout the intestinal phase for all proteins studied, regardless of the scenario. This reinforces the difficulty of linking protein digestibility to potential allergenicity because many other factors are involved that need further investigation.

[Enzymatic hydrolysates of whey protein and chicken egg ppotein: production, physical-chemical and immunochemical characteristics].

Reducing the manifestations of food allergy by the inclusion of specialized foods in the nutrition of children and adults suffering from this disease is an important problem. The aim was to obtain and characterize in vitro food protein hydrolysates to evaluate their use in specialized foods with reduced potential allergenicity. MATERIAL AND METHODS: Whey protein concentrate (WPC) and chicken egg protein (CEP) and enzymes such as pancreatin and alkalase have been used. Proteolysis of proteins was carried out in an FA-10 fermenter for 3 hours at an enzyme : substrate ratio of 1:50 in dry matter, at optimal pH and temperature for pancreatin and alkalase. Enzymes were inactivated at +75 °C and fermentolizate was ultrafiltered. The solutions were concentrated by reverse osmosis and freeze-dried. The molecular weight distribution of the peptide fractions was evaluated by HPLC. Residual antigenicity was determined by the method of indirect enzyme-linked immunosorbent assay and expressed as the fold of antigenicity reduction relative to the original protein. RESULTS AND DISCUSSION: During WPC proteolysis with pancreatin the hydrolyzate was obtained with a fold reduction of antigenicity of 2.3×103 relative to the initial WPC. A decrease in antigenicity of 4.7×104 times was achieved with proteolysis of WPC by alkalase. The combination of WPC fermentolysis with pancreatin or alkalase followed by ultrafiltration reduced the content of high molecular weight peptides with a mass more than 8.7 kDa. The multiplicity of decrease in antigenicity with respect to the starting protein was 1.64×105 and 1.90×105, respectively. After repeated ultrafiltration the reduction in antigenicity of the obtained WPC alkalase or pancreatin hydrolysate was more than 1.0×106 and more than 5.0×105, respectively. The decrease in antigenicity of the CEP hydrolyzate obtained with proteolysis by alkalase and ultrafiltration compared to the initial CEP was 1.0×105 times, and 5.0×105 times when we used repeated ultrafiltration. CONCLUSION: A significant decrease in the content of high molecular weight peptides and a decrease in the antigenicity of peptide mixtures based on WPC and CEP to the values that permit their use in hypoallergenic products is achieved by combining proteolysis and double ultrafiltration through a UF10 membrane.

The frequency of cross-reactivity with various avian eggs among children with hen's egg allergy using skin prick test results: fewer sensitizations with pigeon and goose egg.

INTRODUCTION AND OBJECTIVES: A high rate of cross-reactivity has been reported between the specific proteins of hen's egg with proteins of various avian eggs by quantitative immunoelectrophoretic techniques. The aim of this study was to assess the clinical cross-reactivity of different birds' eggs in children with hen's egg allergy based on skin prick test results. MATERIAL AND METHODS: This cross-sectional study enrolled 52 infants with hen's egg allergy and 52 healthy infants with no history of food allergy from October 2018 to April 2019. Skin prick tests were performed in both patient and control groups with fresh extract of white and yolk related to pigeon, duck, goose, turkey, quail, and partridge. RESULTS: Fifty (96.1%) children with hen's egg allergy showed positive sensitization to at least one of the avian eggs. The most frequent positive skin tests were related to quail's white (36 = 69.2%) followed by duck's white (34 = 65.5%), and sensitization was the least frequent in pigeon's yolk (23 = 44.2%). Skin tests of the control group were negative to all the tested extracts. CONCLUSION: Because of fewer sensitizations to some avian eggs, further research should clarify starting oral immunotherapy with the yolk of goose and pigeon in children with hen's egg allergy.

Eosinophilic esophagitis is probably a comorbid condition in egg-allergic patients undergoing egg oral immunotherapy

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Alleviation of Metabolic Syndrome with Dietary Egg White Protein.

Abdominal fat accumulation causes metabolic syndrome, which is a cluster of metabolic abnormalities such as dyslipidemia, glucose intolerance, insulin resistance or hyperinsulinemia, and hypertension, leading to the development of diabetes and cardiovascular disease. Diets are known to contribute to the development or prevention of metabolic syndrome. Several studies have reported that the quality of dietary proteins may be an important modulator of the risk of this syndrome. We investigated the effects of consuming egg white protein (EWP) or lactic-fermented egg white (LE), an easy-to-consume form of egg white, on the development of metabolic syndrome in animal models and humans. In comparison with casein, dietary EWP decreased lymphatic lipid transport in thoracic lymph duct-cannulated rats. In an in vitro experiment, EWP pepsin hydrolysate decreased the cholesterol micellar solubility and cholesterol transfer rate from micelles to oil phase, and increased water-holding capacity, settling volume in water, and relative viscosity compared with casein pepsin hydrolysate. The daily consumption of LE for 8 weeks reduced serum total cholesterol and LDL cholesterol levels in men with mild hypercholesterolemia. Furthermore, dietary EWP reduced the body fat mass of rats by increasing the body protein mass and accelerating hepatic ß-oxidation. The daily consumption of LE for 12 weeks reduced the visceral fat area and improved the ratio of the visceral to subcutaneous fat area. Taken together, these results indicated that dietary EWP and LE would be useful for preventing or alleviating metabolic syndrome.

Influences of fermentation and ripening temperatures on the enzymatic activity and physicochemical and sensory properties of salted egg white sufu.

This study developed a novel form of sufu. Salted egg white sufu (SEWS) was produced by fermenting steamed salted egg white with douchi koji and ripening at 25°C, 35°C, or 45°C for 19 days. The results show that the protease activity of the koji reduced pronouncedly during fermentation, whereas the one in the SEWS initially increased but subsequently decreased. The total nitrogen and amino nitrogen contents and degree of protein hydrolysis increased during fermentation and decreased during preripening. SEWS, particularly processed at 35°C, contained more free amino acids, notably glutamic acid and leucine, than steamed salted egg white did. After processing, SEWS had darker colors, particularly when manufactured at higher temperatures, and hardness and springiness decreased. The 35°C and 45°C SEWS had higher sensory acceptability. In conclusion, ripening at 35°C for 19 days is recommended for producing this novel animal protein-based sufu.

Dietary Egg Protein Prevents Hyperhomocysteinemia via Upregulation of Hepatic Betaine-Homocysteine S-Methyltransferase Activity in Folate-Restricted Rats.

BACKGROUND: Hyperhomocysteinemia is associated with increased cardiovascular disease risk. Whole eggs contain several nutrients known to affect homocysteine regulation, including sulfur amino acids, choline, and B vitamins. OBJECTIVE: The aim of this study was to determine the effect of whole eggs and egg components (i.e., egg protein and choline) with respect to 1) homocysteine balance and 2) the hepatic expression and activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine ß-synthase (CBS) in a folate-restricted (FR) rat model of hyperhomocysteinemia. METHODS: Male Sprague Dawley rats (n = 48; 6 wk of age) were randomly assigned to a casein-based diet (C; n = 12), a casein-based diet supplemented with choline (C + Cho; 1.3%, wt:wt; n = 12), an egg protein-based diet (EP; n = 12), or a whole egg-based diet (WE; n = 12). At week 2, half of the rats in each of the 4 dietary groups were provided an FR (0 g folic acid/kg) diet and half continued on the folate-sufficient (FS; 0.2 g folic acid/kg) diet for an additional 6 wk. All diets contained 20% (wt:wt) total protein. Serum homocysteine was measured by HPLC and BHMT and CBS expression and activity were evaluated using real-time quantitative polymerase chain reaction, Western blot, and enzyme activity. A 2-factor ANOVA was used for statistical comparisons. RESULTS: Rats fed FR-C exhibited a 53% increase in circulating homocysteine concentrations compared with rats fed FS-C (P < 0.001). In contrast, serum homocysteine did not differ between rats fed FS-C and FR-EP (P = 0.078). Hepatic BHMT activity was increased by 45% and 40% by the EP (P < 0.001) and WE (P = 0.002) diets compared with the C diets, respectively. CONCLUSIONS: Dietary intervention with egg protein prevented elevated circulating homocysteine concentrations in a rat model of hyperhomocysteinemia, due in part to upregulation of hepatic BHMT. These data may support the inclusion of egg protein for dietary recommendations targeting hyperhomocysteinemia prevention.

Co-ingestion of Black Tea Reduces the Indispensable Amino Acid Digestibility of Hens' Egg in Indian Adults.

BACKGROUND: Tea, a commonly consumed beverage, contains high amounts of polyphenols that can impair protein digestibility, as demonstrated in vitro. There are no human studies examining the inhibitory influence of tea polyphenols (TPP) on high-quality protein digestibility. OBJECTIVE: The aim of this study was to determine the effect of black tea on the true indispensable amino acid (IAA) digestibility of whole boiled egg protein, in healthy adult humans, through use of a dual isotope tracer approach. METHODS: The effect of black TPP (4.6 mg/mL, ingested as a beverage with the meal) on 2H-labeled whole boiled egg protein, administered with ghee rice and tomato curry, was measured with reference to 13C-spirulina protein in healthy Indian adults aged 20-27 y of both sexes with BMI of 22.0 ± 2.8 kg/m2. The results were then compared to previously determined whole egg mean IAA digestibility measured by the same method, without black tea, in the same subjects (n = 5). To correct for any independent effect of TPP on spirulina protein (used as a standard protein), the true IAA digestibility of 13C-spirulina protein was independently measured with reference to a 2H-amino acid mixture, with and without co-ingestion of black tea, in 3 of the same subjects. RESULTS: The true IAA digestibility of whole boiled egg protein significantly decreased by 17% when co-ingested with black tea. However, there was no significant reduction in the true IAA digestibility of spirulina protein when co-ingested with black tea. CONCLUSIONS: TPP protein interactions reduced whole egg digestibility in healthy Indian adults but had minimal effect on spirulina protein digestibility. In populations who are at risk of dietary quality protein inadequacy, the consumption of tea during or after a meal can further increase the risk of inadequacy. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2018/03/012265.

Electrical resistance oven baking as a tool to study crumb structure formation in gluten-free bread.

Gradientless baking by means of ohmic heating was used for the first time in gluten-free (GF) bread making. Combination thereof with in-line measurements of batter height, viscosity and carbon dioxide (CO2) release proved to be powerful for studying structure formation in GF breads. GF breads studied here were based on (i) a mixture of potato and cassava starches and egg white powder (C/P-S+EW), (ii) rice flour (RF) or (iii) a mixture of RF and egg white powder (RF+EW). The work revealed that bread volume and crumb structure rely heavily on the balance between the moment of CO2 release from batter during baking and that of crumb setting. At the moment of CO2 release, C/P-S+EW bread crumb had already (partly) set, while this was not the case for RF bread crumb, resulting in a collapse and thus low volume of the latter. When a part of RF was replaced by egg white powder, the moment of CO2 release was postponed and the batter collapse was less pronounced, leading to a higher volume and a finer crumb. The presence of egg white proteins in C/P-S+EW or RF+EW batters improved gas cell stabilization. Thus, increasing batter stability or altering the moment of crumb setting results in GF breads with higher volume and a finer crumb structure.

Polymorphisms in the ovoinhibitor gene (OIH) and their association with egg quality of Xinhua E-strain chickens.

1. Chicken ovoinhibitor has been reported to prevent contamination and affect storage for eggs. The objective of the present study was to conduct an association analysis between ovoinhibitor gene (OIH) polymorphisms and egg quality traits in the population of Xinhua E-strain chickens and explore its expression characteristics in different tissues. 2. Three single nucleotide polymorphisms (SNPs) were identified and genotyped, in which one synonymous mutation was located in exon16 (G9810A), one in intron7 (A4363G) and one in intron14 (C8937G). The A4363G and C8937G polymorphisms significantly influenced Haugh unit (HU) and albumen height (AH), while HU and AH in AG and CT heterozygous birds were significantly higher than in birds with homozygous genotypes. Diplotype association analysis showed individuals with an H1H4 diplotype had the highest AH and HU values in the investigated population. 3. RT-qPCR results showed that the expression level of the OIH gene was higher in the oviduct and liver than other tissues. During the development of liver at different phases, a drastic decrease occurred during the period of first ovulation event, which suggests the regulation of some unknown factors effected it. 4. Our results indicated that OIH plays a vital role in egg quality. The combinations of A4363G and C8937G might be potential advantageous molecular markers for improving HU of chicken eggs.