Egg proteins are an excellent source of bioactive peptides. The purpose of this work was to study the effect of cooking methods on the production of angiotensin converting enzyme (ACE) inhibitory ...peptides. Boiled or fried eggs (in the forms of whites, yolks, and whole eggs) were digested by gastrointestinal tract proteases at simulated gut conditions. Fried egg digests showed more potent activity than those of boiled egg digests; the fried whole egg digest had an IC50 value of 0.009 mg protein/mL. This hydrolysate was further purified by cation exchange chromatography and gel filtration chromatography. Seven peptides, Val-Asp-Phe (IC50: 6.59 μM), Leu-Pro-Phe (10.59 μM), Met-Pro-Phe (17.98 μM), Tyr-Thr-Ala-Gly-Val (23.38 μM), Glu-Arg-Tyr-Pro-Ile (8.76 μM), Ile-Pro-Phe (8.78 μM), and Thr-Thr-Ile (24.94 μM), were identified by liquid chromatography−mass spectrometry (LC-MS/MS), and their IC50 values were predicted by using our previously reported structure and activity models. The presence of several tripeptides from in vitro simulated gastrointestinal egg digest indicates that these peptides may be absorbed into the body and exert an in vivo antihypertensive activity, although in vivo study is needed to confirm this assumption. Our results showed that in vitro digestion of cooked eggs could generate a number of potent ACE inhibitory peptides which may have implications for cardiovascular disease prevention, including hypertension.
Increased demand in consumer choice has resulted in a wide variety of egg selection available in the retail market. Specialty and designer chicken eggs represent a portion of the table egg market ...that is increasing in size. Egg quality is known to be of great importance in all eggs as it relates to food safety, consumer preferences, and product value. In this study, egg quality characteristics were analyzed using a one-way ANOVA to evaluate 2 commercially available conventional egg brands (A and B) and 4 commercially available designer egg brands (C–F). Three hundred nine eggs were evaluated for shell and content weight, dimensional measurements, and breakage force. Calculations were completed to determine %yolk and albumen, yolk index, and Haugh units (HU), followed by an accelerated lipid oxidation study. No significant variation exists in breakage force. Brands A–E meet AA grade standard at a score of 72 HU or above, while brand F, a pasture-raised brand, meets the A grade standard, falling between 60 and 71 HU. Brand F has the highest yolk fan color value (10.41 ± 0.193, P < 0.001) and the lowest yolk index (0.523 ± 0.013, P < 0.05). In addition, brand F has the lowest albumen height (P < 0.001). As albumen height is an indication of freshness, and as all eggs were of equivalent age, it is possible that brand F exhibits overall lower quality than other brands. The conventionally raised white eggs of A experienced the greatest increase in % free fatty acids, which would likely result in off-flavors from hydrolytic rancidity. The organic cage-free D eggs have a significantly greater peroxide value (17.3 ± 2.9, P < 0.001), relative to all other brands, and is over the 10 mEg/kg threshold, which would be considered an unsuitable product for consumption. Ultimately, the measures of egg quality used in this study are essential for evaluating the delivery of the specialty market to the consumer and may indicate that improved measures of quality are needed to truly differentiate between the different egg types and their quality.
•Eggs are inexpensive source of high-quality protein.•Eggs are susceptible to quality loss and microbial contaminations.•Edible coatings are able to maintain the quality and safety of eggs.
Eggs are ...staple food in the human diet and are consumed globally. They represent a complete food required for well-being and are recognized by consumers as versatile and wholesome with a balance of essential nutrients. However, eggs are perishable and susceptible to contamination with certain microorganisms. Past studies concluded that edible coatings have been successful to maintain the interior quality and reduce the microbial load on the eggshell surface. This paper provides an overview of the egg quality and safety and discusses the application of various types of lipid-, polysaccharide-, and protein-based edible coating systems on eggs. Edible coatings could be a viable alternative to existing techniques for maintaining the internal quality and safety of fresh eggs during long-term storage.
This study investigated the effects of copper ions on egg white (EW) gel induced by strong alkali. Changes in gel characteristics were examined through texture profile analysis, scanning electron ...microscopy (SEM), and chemical methods. The value of gel strength reached its maximum when 0.1% copper ions was added. However, the lowest cohesiveness values were observed at 0.1%. The springiness of gel without copper ions was significantly greater than the gel with copper ions added. SEM results illustrated that the low concentration of copper ions contributes to a dense and uniform gel network, and an open matrix was formed at 0.4%. The free and total sulphhydryl group content in the egg white protein gel significantly decreased with the increased copper. The increase of copper ions left the contents of ionic and hydrogen bonds basically unchanged, hydrophobic interaction presented an increasing trend, and the disulfide bond exhibited a completely opposite change. The change of surface hydrophobicity proved that the main binding force of copper induced gel was hydrophobic interaction. However, copper ions had no effect on the protein component of the gels. Generally, a low level of copper ions facilitates protein-protein association, which is involved in the characteristics of gels. Instead, high ionic strength had a negative effect on gels induced by strong alkali.
The Striped Cuckoo (Tapera naevia) is an obligate brood parasite with poorly understood breeding habits. Here, we describe the reproductive biology of Striped Cuckoos parasitizing Rufous-fronted ...Thornbird (Phacellodomus rufifrons) nests in the Cerrado of central Brazil and discuss parasite adaptations. Striped Cuckoos parasitized 38.5% of Rufous-fronted Thornbird nests in October-November. Cuckoos laid I white elliptical egg per thornbird nest. The mean mass of eggs was 2.64 g and the mean size was 21.0 * 15.3 mm (n = 4). Striped Cuckoo egg incubation period had a duration of 14.7 + or - 1.4 d (n = 7), 2.4 d less than eggs of the Rufous-fronted Thornbird (17.1 + or - 2.2 d; n = 8). Striped Cuckoo nestlings were very aggressive, pecking their nest mates to death, and the single cuckoo nestling remained alone in parasitized nests for 20.8 + or - 1.2 d (n = 8), a duration similar to its host in nonparasitized nests (19.7 + or - 1.6 d; n = 14). The mass gain of cuckoo nestlings was faster (3.0 g/d) than thornbird nestlings in nonparasitized nests (1.7 g/d). The predation rate during the nestling stage was similar for nests with a Striped Cuckoo nestling (20%) to that of nonparasitized nests with thornbird nestlings (26%). We propose that several adaptations allow Striped Cuckoos to successfully parasitize Rufous-fronted Thornbird nests: a highly mimetic egg, as the host's egg was also white and elliptically shaped, a smaller egg in proportion to body size, the ability of its nestlings to puncture or eject host eggs and kill host nestlings, a shorter incubation period, a faster nestling mass gain, and a flexible breeding season. Received 9 December 2020. Accepted I March 2022.
Bird eggs are commonly used in contaminant monitoring programs and toxicological risk assessments, but intraclutch variation and sampling methodology could influence interpretability. The authors ...examined the influence of egg‐laying sequence on egg mercury concentrations and burdens in American avocets, black‐necked stilts, and Forster's terns. The average decline in mercury concentrations between the first and last eggs laid was 33% for stilts, 22% for terns, and 11% for avocets, and most of this decline occurred between the first and second eggs laid (24% for stilts, 18% for terns, and 9% for avocets). Trends in egg size with egg‐laying order were inconsistent among species, and overall differences in egg volume, mass, length, and width were <3%. The authors summarized the literature, and among 17 species studied, mercury concentrations generally declined by 16% between the first and second eggs laid. Despite the strong effect of egg‐laying sequence, most of the variance in egg mercury concentrations still occurred among clutches (75–91%) rather than within clutches (9%–25%). Using simulations, the authors determined that accurate estimation of a population's mean egg mercury concentration using only a single random egg from a subset of nests would require sampling >60 nests to represent a large population (10% accuracy) or ≥14 nests to represent a small colony that contained <100 nests (20% accuracy). Environ Toxicol Chem 2016;35:1458–1469. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.
A reliable and rapid method has been developed for the determination of 10 mycotoxins (beauvericin, enniatin A, A1, B1, citrinin, aflatoxin B1, B2, G1, G2 and ochratoxin A) in eggs at trace levels. ...Ultra-high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) has been used for the analysis of these compounds in less than 7
min. Mycotoxins have been extracted from egg samples using a QuEChERS-based extraction procedure (Quick, Easy, Cheap, Effective, Rugged and Safe) without applying any further clean-up step. Extraction, chromatographic and detection conditions were optimised in order to increase sample throughput and sensitivity. Matrix-matched calibration was used for quantification. Blank samples were fortified at 10, 25, 50 and 100
μg
kg
−1, and recoveries ranged from 70% to 110%, except for ochratoxin A and aflatoxin G1 at 10
μg
kg
−1, and aflatoxin G2 at 50
μg
kg
−1. Relative standard deviations were lower than 25% in all the cases. Limits of detection ranged from 0.5
μg
kg
−1 (for aflatoxins B1, B2 and G1) to 5
μg
kg
−1 (for enniatin A, citrinin and ochratoxin A) and limits of quantification ranged from 1
μg
kg
−1 (for aflatoxins B1, B2 and G1) to 10
μg
kg
−1 (for enniatin A, citrinin and ochratoxin A). Seven samples were analyzed and aflatoxins B1, B2, G1, G2, and beauvericin were detected at trace levels.
Dietary intake is a major route of human exposure to perfluoroalkylated substances (PFASs). However, the available information on PFAS levels in food, including chicken eggs, is limited. In the ...present study, home produced and commercially produced eggs (organic, battery and free range eggs) were collected from the Netherlands (n = 95) and Greece (n = 76). The egg yolks were analysed for 11 PFASs by liquid chromatography-tandem mass spectrometry using isotope dilution. PFAS levels in yolk were higher in home produced eggs from the Netherlands (median 3.1, range < LOQ – 31.2 ng g−1) and Greece (median 1.1, range < LOQ – 15.0 ng g−1) compared to the eggs collected from supermarkets. In these eggs, all PFAS levels were below the LOQ of 0.5 ng g−1, except for a small amount of perfluorooctane sulfonate (PFOS) in 1 sample in each country (1.1 ng g−1 and 0.9 ng g−1 for the Netherlands and Greece respectively).
PFOS was the predominant PFAS, making up on average 85% of ∑PFASs. The highest PFOS concentration was detected in a Dutch home produced egg sample (24.8 ng g−1). The contamination pattern was similar in both countries with the long-chain PFASs (C ≥ 8) being most frequently detected, while short-chain PFASs were rarely found. The most likely cause of the contamination of home produced eggs is ingestion of soil through pecking. Although regular consumption of home produced eggs will lead to an increased PFOS exposure, it is not expected that it will lead to exceedance of the tolerable daily intake established by EFSA.
•Perfluoroalkylated substances (PFASs) detected in home produced eggs.•Long-chain PFASs, especially PFOS, detected more frequently than short-chain PFASs.•No PFASs in most commercial eggs from the Netherlands and Greece.•Consumption of home-produced eggs unlikely to lead to exceedance TDIs.
: Hempseed (HS) is rich in omega‐3 polyunsaturated fatty acids, with approximately 17% of total fatty acids as alpha‐linolenic acid. As such, HS and its oil may be used in hen diet formulations to ...produce eggs enriched in essential fatty acids. Because omega‐3 eggs have the potential for unpleasant aromas and flavors, the current study was designed to assess the fatty acid profile and sensory attributes of eggs procured from hens consuming diets containing hempseed oil (HO) or HS. A total of 48 individually caged White Bovan hens received 1 of 6 diets containing 4%, 8%, 12% HO, 10%, 20% HS or 0% hemp (w/w) for 12 wk. Total omega‐3 polyunsaturated fatty acid content was highest in the 12% HO group (15.3 mg/g of yolk) compared to the control (2.4 mg/g of yolk). Trained panellists (n= 8) found no significant differences (P≥ 0.05) in aroma or flavor between cooked eggs from different dietary treatments, with the exception of sweet flavor. The 4% HO group yielded the least sweet eggs compared to the 20% HS group, which was highest. For yolk color, L*, a*, and b* values (Mean ± SEM) for control eggs were 61.2 ± 0.10, 1.1 ± 0.05, and 43.0 ± 0.22, respectively. Addition of hemp led to significant (P < 0.001) reductions in L*, and significant increases in a* and b*, with the largest changes observed in the 20% HS treatment (L*= 58.7 ± 0.10; a*= 5.8 ± 0.05; b*= 60.5 ± 0.22). The results show that hemp use in hen diets leads to increased omega‐3 polyunsaturated fatty acid content and color intensity of egg yolks, but does not have adverse effects on the sensory profiles of the cooked eggs.
Practical Application: This study provides evidence that HS and hempseed oil (HO) can safely be utilized as feed ingredients for laying hens to produce table eggs that are enriched in essential fatty acids. Additionally, the eggs procured from these hens had similar aroma and flavor compared to eggs from hens not fed any hemp. The greater the dietary hemp inclusion, the more pigmented the resulting yolks became in terms of darkness, redness, and yellowness.
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