Regular Eggs Research Articles

Riboflavin Binding Protein and Riboflavin Transport to Hen Eggs as an Educational Tool

Riboflavin Binding Protein (RBP) is a stable glycophosphoprotein abundant in the eggs of many oviparous species, including chickens. The function of the protein is to transfer riboflavin (Rf) to the developing embryo, and recent evidence suggests it also binds copper. Because of its bright yellow color and fluorescence, Rf transport serves as an excellent model system. A natural mutant strain of white leghorn chickens, containing a site mutation, is unable to synthesize RBP and thus the eggs are devoid of Riboflavin. We are currently investigating the protein and mutant egg use for both an undergraduate biochemistry lab (1) as well as an outreach project for K-12 students (2). The undergraduate research-style experiment for advanced biochemistry lab students is a useful exercise in learning protein purification techniques, including dialysis, salt precipitation and chromatography. Because of the holoRBP yellow color, it is easy to follow, and its stability renders it possible to carry out steps over time at room temperature. We have modified a standard procedure and students have successfully purified protein. Using the mutant and regular chicken eggs we have modified an education series as an informative and didactic approach towards problem-based learning. Our main motive was to perform outreach to K-12 with an interactive experiment featuring the importance of vitamins and the mechanisms of molecular transport.

Egg yolks inhibit activation of NF-κB and expression of its target genes in adipocytes after partial delipidation.

How composition of egg yolk (EY) influences NF-κB, a key transcription pathway in inflammation, remains unclear. We performed partial delipidation of EY that removed 20-30% of cholesterol and triglycerides. The resulting polar and nonpolar fractions were termed EY-P and EY-NP. NF-κB activation in response to EY from different suppliers and their fractions was examined in 3T3-L1 adipocytes using a NF-κB response element reporter assay and by analyzing expression of 248 inflammatory genes. Although EY-P and EY contained similar level of vitamins, carotenoids, and fatty acids, only delipidated EY-P fraction suppressed NF-κB via down-regulation of toll like receptor-2 and up-regulation of inhibitory toll interacting protein (Tollip) and lymphocyte antigen 96 (Ly96). Our data suggest that anti-inflammatory activity of lutein and retinol were blunted by nonpolar lipids in EY, likely via crosstalk between SREBP and NF-κB pathways in adipocytes. Thus, moderate delipidation may improve the beneficial properties of regular eggs.

30. Cryopreservation of Daphnia magna genotypes

The water flea Daphnia magna is an important model organism in ecological and evolutionary biological research and it is the most popular invertebrate model in ecotoxicology. One of the big advantages of using Daphnia in research lies in its mode of reproduction. The life cycle of Daphnia is characterized by an alternation of sexual and asexual reproduction, called cyclic parthenogenesis, which enables researchers to work with clonal lines and provides an unlimited amount of genetically identical individuals for experiments. In nature sexual reproduction occurs during autumn and winter and results in the production of dormant eggs. During the following spring the dormant eggs hatch and give rise to a population of female animals that will reproduce asexually and produce clones as long as the environmental conditions are favorable. The dormant eggs are designed to survive harsh environmental conditions and are perfectly able to cope with severe freezing temperatures and drought. It is also possible to freeze them in liquid nitrogen without the use of cryoprotectants and revive them without significant loss of viability. The parthenogenetic eggs on the other hand, cannot be cryopreserved yet and maintenance of the clonal lines can only be achieved through continuous culturing. This is a labor intensive process and it is not without risk of losing important lines because of contamination or disease. Cryopreservation could provide us with a welcome alternative. We propose the following approach to tackle this challenge. As a first step we compare the biochemical characteristics (lipids, sterols, sugars, polyamines and proteins) of the stress resistant sexual eggs with the more stress sensitive asexual eggs. This provides us with insights on how to manipulate asexual eggs so that they become suitable for cryopreservation. We already observed several differences in this perspective. For instance sexual eggs contain more trehalose than asexual eggs. And since trehalose is known for its capacities to protect cells against freezing damage, this substance can be of big interest. Also the sterol and lipid content differs, the asexual eggs contain more cholesterol and the lipids of the sexual eggs tend to be longer and more unsaturated. Through manipulation of the culture conditions (cold shocks, etc.) and diet composition of the mother individuals (trehalose enriched yeast, liposomes, etc.) we try to alter the biochemical content of the clonal eggs so that they become more stress resistant. After each treatment we evaluate the newly acquired stress tolerance of the asexual eggs. In parallel with this first approach we are working on the development of a suitable cryopreservation protocol in a systematic way. First we developed an osmoprotection treatment using glycerol. At the moment we are testing the toxicity of several vitrification solutions. This will be followed by the development of appropriate dehydration, cooling, thawing and recovery protocols. After each step survival of the hardened and regular asexual eggs is compared.

鶏卵流通における継続的取引と鳥インフルエンザ発生時の取引継続の可能性に関する研究

Eggs are traded successively between certain parties. In this article, the mechanism of this successive trade relationship is investigated to examine the possibility of the continuity of trade after an avian influenza (AI) outbreak. The concepts of relational contracts and relation-specific skills are employed to model the mechanism, and the derived models are then employed to check the trade continuity in the case of an AI outbreak. Some solutions expected to avoid trade termination have already been proposed, and two of them are analyzed in this study to gauge their effectiveness. The main results are as follows: in the successive trade between producer (farmer) and retailer, the growth of relation-specific and versatile skills does not necessarily lead to an increase in the relational quasi-rent as to convince both parties to continue that trade. In addition, significant damage to the relational quasi-rent for branded eggs is expected in an AI outbreak. This will make trade continuity rather difficult. In the successive trade through wholesalers, producers have some difficulty in developing their skills in the successive trade of regular eggs, especially through wholesalers who only act as middlemen. Although it may be easy for the producer to prepare substitute eggs for AI in this case, the trade will not easily continue after the eradication. Analysis of the solutions shows that trade continuity can be fortified by the following measures: developing relation-specific skills between producer and retailer, preparing a supply structure that absorbs some of the reduction in the value of eggs in the case of AI, and setting proper quality standards for substitute eggs.

Influences of demographic characteristics, attitudes, and preferences of consumers on table egg consumption in British Columbia, Canada

In addition to regular (white and brown) eggs, alternative types of table eggs (e.g., free-run, free-range, organic) are available in the Canadian market, and their market growth rate has been high during the last decade in British Columbia (BC). The objective of our research was to identify associations between consumers’ attitudes, preferences, and demographic characteristics with their consumption of different types of table eggs. An online survey was conducted in June 2009 to gather information from adult BC residents. Sixty-eight percent of the 1,027 randomly selected subjects completed the survey. Our survey indicated that the consumption of cage-free specialty eggs (free-run, free-range, and organic) has strongly increased in BC to 32.9% free-range eggs, 11.93% organic eggs, and 7.6% free-run eggs in 2009 compared with a Print Measurement Bureau consumer survey that showed combined 8% consumption of cage-free specialty eggs in 2007. Results of our survey indicated that, compared with consumers of white regular eggs, consumers of free-range eggs came from smaller households and had a higher education level and income. These consumers indicated that factors of health, nutritional value, environmental issues, and animal welfare were important in egg type selection. Although most consumers rated the specialty eggs as having a higher nutritional value than white regular eggs, price became the most important deciding factor for those consumers who selected white regular eggs. Our findings indicate that increased consumption and increased differentiation exist in the table egg market and this in turn provides support for more research to increase the efficiency of cage-free egg production systems and for better consumer education.

Effects of Egg Yolk Source on the Cryopreservation of Stallion Spermatozoa

Three experiments were conducted to determine whether replacement of chicken egg yolk, as a component of freezing extenders, with egg yolk from other avian species would improve the post-thaw motility and percentage of intact acrosomes of stallion spermatozoa. In the first experiment, substitution of chicken egg yolk with chukar egg yolk, as a component of the lactose–ethylenediaminetetraacetic acid extender, improved (P ≤ .05) the post-thaw motility of stallion spermatozoa. These results were not replicated in (IMV Technologies, Maple Grove, MN, USA) a more expansive study comparing 2%, 4%, 6%, or 8% egg yolk combined with INRA 96 when a “slow freeze” method was used, or the same substitution at levels ranging from 13% to 22% when egg yolk was combined with lactose–ethylenediaminetetraacetic acid for diluents used for a “fast freeze” method of cryopreservation. In the third study, egg yolks from regular and high omega-3 chicken eggs as well as from turkey, chukar, and mallard duck eggs were analyzed for lipid content and fatty acid profile. The yolk from the turkey eggs was higher (1,300 mg/100 g) and that from mallard ducks was lower (560 mg/100 g) in cholesterol as compared with the two types of chicken eggs and chukar egg yolk (range, 1,046-1,094 mg/100 g). In addition, the high omega-3 eggs did test higher for fatty acids (4.51 g/100 g) than other types of eggs (range, 0.28-0.73 g/100 g). Substitution of chicken egg yolk with turkey, but not duck, egg yolk resulted in higher post-thaw total motility (P ≤ .05) for spermatozoa obtained from two of the three stallions used in the third experiment.

Every egg may have a targeted purpose: toward a differential approach to egg according to composition and functional effect

Despite the suggested health advantages of traditionally- over industrially-produced western ‘regular’ eggs and the flexibility of egg composition, studies on the effects of egg intake refer mostly to quantity and lack qualitative information. The possibility of lending differential nutritional enhancement and functional advantages, i.e. vs. cardiovascular disease (CVD) or for perinatal health, could impact the current egg intake debate. N-3 polyunsaturated fatty acid (PUFA)/long-chain PUFA (LCPUFA) fortification of regular eggs by feeding extruded linseed (5%) yielded 3.8-fold higher total n-3 PUFA and 2.4-fold higher docosahexaenoic acid (DHA), with 3.6-fold lower n-6:n-3 PUFA ratio (p≤0.0005). This resulted in human dietary contributions of 10–20% of the n-3 PUFA Dietary Reference Intake (DRI) and 40% for DHA. Together with antioxidants, they may be beneficial against CVD risks as associated with oxidative stress, endothelial dysfunction, dyslipidemia, and inflammatory processes, especially in diabetics. Eggs fortified via poultry feed supplementation could attain higher %DRI for pregnancy or lactation for key nutrients, i.e. DHA (≈120- 130%), vitamins A (9.0-15.2%) and E (51.6-65.3%), iodine (15.2-20.1%), and selenium (33.7-39.3%). For infants aged 1–3 years, the improvement in %DRI for vitamins, minerals, and n-3 PUFA needed during peak brain development could be even higher. Compared to increased low-density lipoprotein (LDL) oxidation as seen with intake of two regular high n-6 PUFA eggs/day, eggs with reduced n-6 PUFA (by 40%), increased n-9 monounsaturated FA (MUFA) (by 30%), reduced PUFA:MUFA ratio (by 50%), and increased antioxidants vitamin E and carotenoids (by >200%), were associated with a 30% drop in LDL oxidisability (p<0.01), back to levels seen with a low-egg diet (2–4 eggs/week). Because egg composition is highly feed-dependent and closely affects plasma nutrients and lipoprotein composition and physiological qualities, it has much potential for imparting both nutritional and functional benefits. Poultry feeding could be carefully tailored for egg modification to address specific risks and requirements in consumers, warranting further research regarding differential effects and corresponding quantitative recommendations for egg intake, to maximise beneficial and preventative potential.

Consumption of either one egg or lutein‐enriched egg per day increases HDL cholesterol, reduces apolipoprotein B while increasing plasma carotenoids and macular pigment density in adult subjects

In this study, subjects were assigned to consume either one egg (n =11), one egg substitute (n = 12) or one egg fortified with 600 μg of lutein (n = 11) per day. We measured plasma lipids, LDL subfractions and circulating carotenoids, macular pigment density (MPOD) by use of a densitometer, and hand carotenoids by use of a biophotonic scanner at baseline and after 12 wk. No changes in plasma LDL cholesterol or triglycerides were observed over time. However, both egg groups presented increases in HDL cholesterol compared to baseline (P &lt; 0.01). All subjects had decreases in apolipoprotein B (P &lt; 0.05) associated with a lower number of small LDL particles (P &lt; 0.01). Independent of source, egg intake increased MPOD (P &lt; 0.01) while hand carotenoids did not change over time for any of the groups. Plasma lutein concentrations increased by 9% (P &lt; 0.01) and by 35% (P &lt; 0.001) in the egg and lutein‐enriched egg groups, respectively. In this study we have demonstrated that MPOD increases whether subjects are consuming regular eggs or lutein enriched eggs. However, circulating lutein concentrations were associated with higher intake of this carotenoid, which may increase antioxidant protection in plasma. These studies demonstrate that consuming one egg per day may protect the eye against macular degeneration while increasing HDL cholesterol and favoring the formation of less atherogenic particles. [Supported by the Egg Board]

Analysis of Fatty Acid Methyl Esters in Egg Yolk Using GC–MS

To determine the fatty acid content of egg yolk lipids, fatty acid esters in egg yolk are transesterified, converting them to more volatile fatty acid methyl esters (FAMEs). These FAMEs are separated using gas chromatography (GC), detected using electron ionization mass spectrometry (MS), and identified using a mass spectral library. After integrating the GC peaks, students determine the relative amounts of FAMEs in their samples. Students then compare their results to the literature values for FAMEs in egg yolk and comment on differences between their data and the literature. Both regular large eggs and large eggs from a commercial supplier of eggs stated to be higher in polyunsaturated fatty acids (PUFA) are examined.

Regular eggs and lutein‐enriched eggs increased macular pigment density without changing plasma lipids

We recruited 14 subjects (11 women and 5 men) aged 40‐70 y old to evaluate the effects of regular egg and lutein‐enriched eggs on plasma lipids and macular pigment density (MPOD). All subjects consumed the equivalent of 7 eggs/wk and they were randomly allocated to egg substitute (SUB, 0 mg cholesterol, 0 mg lutein per d), regular eggs (EGG, 213 mg cholesterol, 200 µg lutein per d) or lutein‐enriched eggs (L‐EGG, 213 mg cholesterol, 6 mg lutein per d). We measured weight, blood pressure, waist circumference, skin carotenoids, MPOD and plasma lipids both at baseline and after 6 wk. There were no changes in body weight or systolic and diastolic blood pressure for all subjects. Plasma triglycerides did not change between baseline and 6 wk. There were also no changes in total cholesterol, LDL‐C, HDL‐C or skin carotenoids between baseline and 6 wk. However, MPOD was significantly increased for both the EGG (0.27 ± 0.04 at baseline to 0.39 ± 0.09 6 wk) and the L‐EGG (0.39 ± 0.10 at baseline and 0.46 ± 0.12 at 6 wk) (P &lt; 0.01) while no changes were seen for the egg substitute group (0.41 ± 0.09 at baseline and 0.42 ± 0.07 at week 6). These results confirm that egg is a good vehicle for dietary carotenoid absorption and that increased dietary lutein correlates with MPOD and not with skin carotenoids. The results also indicate that consuming one egg per day did not raise plasma cholesterol in this group of subjects [Supported by the American Egg Board]

Food Consumption and the Risk of Type 1 Diabetes in Children and Youth: A Population-Based, Case-Control Study in Prince Edward Island, Canada

Objective: The objective of this study was to determine if the consumption of certain foods during the year prior to diagnosis of type 1 diabetes mellitus (T1D) was associated with the risk of developing T1D in children and youth residing in Prince Edward Island, Canada.Methods: Cases (n = 57) consisted of newly diagnosed patients with T1D during 2001 to 2004. Controls (n = 105) were randomly selected from the province's population, and matched to cases by age at diagnosis and sex. Food consumption in cases and controls was assessed using two previously validated food frequency questionnaires, and a survey was developed to collect information on potential environmental and genetic risk factors.Results: The median age at diagnosis was nine years, and 67% of cases were male. After controlling for the matched variables and four significant environmental and genetic risk factors (family members with T1D, the number of infections during the first two years of life, place of residence, and father's education) in the final logistic regression model, the consumption of regular soft drinks (OR = 2.78, 95% CI = 1.21, 6.36) and eggs (OR = 2.50, 95% CI = 1.09, 5.75) were significant risk factors of T1D, when consumed once per week or more often.Conclusion: Diet may play a role in the development of T1D. However, further research is needed to confirm these observed associations.

FoodNet Survey of Food Use and Practices in Long-Term Care Facilities

Foodborne illness is an important problem among the elderly. One risk factor for foodborne illness and diarrhea-associated mortality among the elderly is residence in a long-term care facility (LTCF); thus, these facilities must implement measures to ensure safe food. To assess safe food practices, knowledge, and policies, we used a mailed, self-administered questionnaire to survey food service directors at LTCFs that were certified to receive Medicare or Medicaid at eight Foodborne Diseases Active Surveillance Network (FoodNet) sites. Surveys were distributed to 1,630 LTCFs; 55% (865 of 1,568) of eligible facilities returned a completed questionnaire. Only three LTCFs completely followed national recommendations for prevention of Listeria monocytogenes contamination. Nine percent of LTCFs reported serving soft cheeses made from unpasteurized milk. Most LTCFs reported routinely serving ready-to-eat deli meats; however, few reported always heating deli meats until steaming hot before serving (only 19% of the LTCFs that served roast beef, 13% of those that served turkey, and 11% of those that served ham). Most LTCFs (92%) used pasteurized liquid egg products, but only 36% used pasteurized whole shell eggs. Regular whole shell eggs were used by 62% of facilities. Few LTCFs used irradiated ground beef (7%) or irradiated poultry products (6%). The results of this survey allowed us to identify several opportunities for prevention of foodborne illnesses in LTCFs. Some safety measures, such as the use of pasteurized and irradiated foods, were underutilized, and many facilities were not adhering to national recommendations on the avoidance of certain foods considered high risk for elderly persons. Enhanced educational efforts focusing on food safety practices and aimed at LTCFs are needed.

Tank Performance of Larval Saugeyes (Walleye × Sauger) Produced Out‐of‐Season and during Regular Season Spawning

AbstractIn the north‐central region of the United States, hybrid saugeyes (female walleye Sander vitreus [formerly Stizostedion vitreum] × male sauger S. canadense) have been recognized as an important species for recreational fisheries and as a potential aquaculture commodity. We compared the performance of larval saugeyes that were produced out of season with larvae produced during the regular spawning season using intensive rearing systems. Fertilized out‐of‐season and regular season saugeye eggs that were produced by crossing two Spirit Lake, Iowa, female walleyes and two Mississippi River male saugers were obtained from the Rathbun Hatchery, Iowa Department of Natural Resources, Moravia. Out‐of‐season spawning was induced by light and photoperiod manipulation. Eyed eggs were air‐shipped overnight at 10°C. First‐feeding larvae (19,000 fish/tank) were stocked in six 800‐L cylindrical tanks provided with turbid water to prevent cannibalism and with surface sprays to secure swim bladder inflation. The fish were fed exclusively with commercial diets (Fry Feed Kyowa B‐400 and B‐700 and Bio‐Oregon starter diet). The specific growth rate (SGR), condition factor, and survival were compared between saugeyes reared out of season (50 d) and during the regular season (39 d). The mean SGR and survival of saugeyes from the out‐of‐season experiment were significantly lower than those of saugeyes from the regular season experiment (P &lt; 0.05), although the condition factor of the fish did not differ between the experiments. Significant differences in SGR were also observed between tank replicates, suggesting possible differences in the feeding responses of saugeyes within a tank system. Large discrepancies (40–43%) were observed between actual survival at the end of the rearing period and predicted survival based on counts of dead larvae siphoned from the tank bottom, suggesting the occurrence of cannibalism and the deterioration of larvae bodies prior to tank cleaning. The actual survival (12–19%) of larval saugeyes in both experiments shows some promise in the intensive rearing of saugeyes exclusively on dry feeds.

Consumption of Omega-3 Fatty Acid-Enriched Eggs and Serum Lipids in Humans

ABSTRACT This study examined the effectiveness of consuming omega-3 fatty acid-enriched eggs (Omega Eggs) in increasing total dietary omega-3 fatty acids. Also examined was the impact of Omega Egg consumption on serum lipids. Sixteen hypercholesterolemic men and women with baseline serum total cholesterol concentrations of 5.17–7.76 mmol/L (200–300 mg/dL) followed the National Cholesterol Education Program Step I diet guidelines under the following conditions: (a) Step I diet without eggs, (b) Step I diet plus 12 regular eggs per week, and (c) Step I diet plus 12 Omega Eggs per week. The study design was a repeated 3X3 Latin square so that each subject received each of the three diet treatments. Consumption of Omega Eggs significantly increased omega-3 fatty acid intake (1.18 g/day) compared to consumption of regular eggs (0.71 g/day) or no eggs (0.81 g/day). The Omega Egg treatment did not significantly alter serum cholesterol or triacylglycerol concentration when all 16 subjects were included in the ana...

Nutritional effect of including egg yolk in the weaning diet of breast-fed and formula-fed infants: a randomized controlled trial

Egg yolks can be a source of docosahexaenoic acid (DHA) and iron but are often associated with adverse consequences on plasma cholesterol. Our goal was to investigate the effect of consumption of 4 egg yolks/wk on infant DHA status and hemoglobin, ferritin, and plasma cholesterol concentrations. Secondary outcomes included plasma iron, transferrin, and transferrin saturation. This was a randomized controlled trial comparing no dietary intervention, consumption of 4 regular egg yolks/wk, and consumption of 4 n-3 fatty acid-enriched egg yolks/wk in breast-fed and formula-fed infants from 6 to 12 mo of age. Erythrocyte DHA concentrations, cholesterol, and iron status were assessed at 6 and 12 mo of age. Of the 82 breast-fed infants recruited, 23 of 28 (no intervention), 23 of 27 (regular eggs), and 24 of 27 (n-3 eggs) completed the trial. Of the 79 formula-fed infants enrolled, 23 of 27 (no intervention), 24 of 26 (regular eggs), and 20 of 26 (n-3 eggs) completed the trial. Erythrocyte DHA concentrations were 30-40% higher after the n-3 egg intervention than after treatment with regular eggs or no eggs in both breast-fed and formula-fed infants. Egg treatment had no significant effect on plasma cholesterol, hemoglobin, ferritin, and transferrin but did result in improvements in plasma iron and transferrin saturation compared with no egg treatment. n-3 Fatty acid-enriched eggs may provide a means of increasing dietary DHA during the second 6 mo of life. Egg yolks may also be a useful source of iron during the weaning period and can be safely included in the weaning diet with no perturbations in plasma cholesterol.

Fatty Acid Composition and Egg Components of Specialty Eggs

Egg components, total fat, and fatty acid content of specialty eggs were compared. One dozen eggs were collected and analyzed from each of five different brands from hens fed a diet free of animal fat (SP1), certified organic free-range brown eggs (SP2), uncaged unmedicated brown eggs (SP3), cage-free vegetarian diet brown eggs (SP4), or naturally nested uncaged (SP5). Regular white-shelled eggs were the control. A significant (P < 0.05) difference was observed in the egg components and fatty acid content in different brands. The percentage of yolk was lower (P < 0.05) in SP2 and SP4 with a concomitant increase (P < 0.05) in the percentage of white. The percentage of shell was lower (P < 0.05) in SP4 and SP5. The total edible portion was greater in SP4 and SP5. The yolk:white ratio was greater (P < 0.05) in SP3. The total lipid content was lower in SP4 eggs. The content of palmitic (C16:0), stearic (C18:0), and total saturated fatty acids were lower (P < 0.05) in SP1. No difference was observed in the content of palmitoleic (C16:1), oleic (C18:1), or total monounsaturated fatty acids. The content of n-3 fatty acids in SP2, SP4, and SP5 were similar to control eggs. The ratio of total n-6:n-3 polyunsaturated fatty acids ranged from 39.2 for SP5 to 11.5 for SP1 (P < 0.05). No difference was observed in the total polyunsaturated fatty acid content of eggs (P > 0.05).

GROWTH, SURVIVAL AND HEAT RESISTANCE OF SALMONELLA TYPHIMURIUM AND ESCHERICHIA COLI IN REGULAR AND OMEGA‐3 HENS EGG PRODUCTS

ABSTRACT Omega‐3 enriched eggs are currently produced by hens fed a flax diet. Since omega‐3 polyunsaturatedfatty acids are prone to oxidation, the addition of vitamin E is supplemented into the hen's diet as an antioxidant. Typically these eggs contain about 2 and 4 times more omega‐3 fatty acids and vitamin E, respectively compared to regular eggs. Since table eggs have a long history of association with foodborne salmonellosis, it was of interest to compare the growth and/or survival of several bacterial pathogens in omega‐3 and regular eggs. In this respect nalidixic‐resistant Escherichia coli and Salmonella Typhimurium were inoculated into regular and omega‐3 hen's egg products (whole eggs, albumen, yolk) and incubated at 22, 8 and −20C. Time‐course studies indicated that by 72 h both Salmonella and E. coli levels increased by 7 logs at 22C in both types of whole egg. At 8C population levels for these bacteria both increased by approximately 3 logs at 6 weeks. In regular and omega‐3 yolks, salmonellae maintained at 22 and 8C for 48 h and 6 weeks increased by approximately 6 and 1.5 logs, respectively. E. coli levels were higher in egg yolk compared to Salmonella at both temperatures. Regardless of the yolk source, however, no significant (P &gt; 0.05) differences in population levels were observed. Survival patterns of E. coli at −20C were not significantly (P &gt; 0.05) different between whole egg sources. This trend was also observed in the yolks. For Salmonella no significant (P &gt; 0.05) differences in survival were observed between yolk preparations maintained at −20C. Increasing the level of α‐tocopherol from c. 63 to 240 ppm in regular egg yolk, resulted in no significant (P &gt; 0.05) differences in the growth of Salmonella at 22C. In addition, when the bacterium was heated in regular egg yolk amended with vitamin E at 56.5C, no significant (P &gt; 0.05) difference was observed in resistance regardless of α‐tocopherol (55‐713 ppm) or total tochopherol (92–1238 ppm) level.

Producing and Marketing a Specialty Egg

Eggland's Best, Inc. markets premium quality shell eggs under the Eggland's Best (EB) brand name. The company, started in 1988, is comprised of a franchise network of established egg producers and covers most of the United States. Eggland's Best provides its franchisees with marketing and technical support. The franchisees produce, process, and distribute EB eggs according to the strict program established and monitored by EB. Production follows the all-natural vegetarian feed program in accordance with the company's US patent entitled “Eggs Compatible with a Cholesterol Reducing Diet and Method of Producing the Same.” The EB program excludes animal fat and other animal byproducts. Eggland's Best eggs have seven times the generic level of vitamin E, nearly three times more omega-3 fatty acids and iodine, and 25% less saturated fat than regular generic eggs. Eggland's Best has one of the finest shell egg quality assurance programs anywhere. Eggland's Best franchisees submit weekly egg samples that are analyzed for shell quality, interior quality, vitamin E, iodine, cholesterol and fatty acids. Samples of feed and the EB-patented feed supplement are also analyzed. Approximately 28,000 total laboratory tests are conducted annually. Nationwide product and display retail evaluations are contracted through an outside audit company (40 to 50 cities evaluated four times per year). All EB eggs are USDA graded according to EB's strict quality standards. Producers must follow a food safety quality assurance program (United Egg Producers Association 5-Star or equivalent state or company program). Each egg is stamped “EB” as assurance of meeting EB's highest standards of flavor, quality, and nutrition. Eggland's Best has enjoyed record sales growth for the past 3 yr.

Cell morphology as an indicator of viability of cod eggs – results from an experimental study

This study evaluates the use of egg malformations, at early blastula stages, as direct indicators of egg viability in cod, Gadus morhua. Eggs with visible aberrations at early stages (4–32 cells) were incubated individually, using regular eggs as controls. Irregular eggs displayed, on an average, a lower hatching rate than the controls, 35% and 80%, respectively, but with substantial variation among batches. In several examples, severe malformations at blastula stages (4–32 cells) resulted in normal hatching. There were no differences in mortality rate during the yolk-sac period between larvae hatching from irregular eggs and controls, respectively, implying similar opportunities for further survival. In addition, artificially fertilized eggs of 17 batches from 11 different females of Baltic cod were incubated after estimations of malformation rate at early blastula stages. Viable hatch varied between 14% and 97% (average 64%, SD=28) among batches and a rank correlation test revealed a significant correlation between malformation rate (average 13%, SD=17) and viable hatch. The results are consistent with those from the individual egg incubation, suggesting that malformations during early stages may affect further development. However, large variations in hatching success, between batches, both from individual egg incubation and from incubation in batches indicate that other factors may be important. This study reveals that severe aberrations occurring at early stages may recover. Thus, malformations occurring at early blastula stages should be used with prudence and not as a direct and consistent indicator of poor egg viability.

Studies of Consumer Acceptance of High Omega-3 Fatty Acid-Enriched Eggs

Two studies were conducted to test the effects of flaxseed or menhaden fish oil with supplemental vitamin E on consumer acceptance, oxidative products, and yolk color of fresh and stored eggs. Trial 1 showed no effect of Ω-3 fatty acid enrichment from flaxseed or fish oil on texture, off-flavors, and consumers’ overall acceptance of fresh eggs, but did show a slight negative effect on appearance and flavor in eggs from hens fed high levels (10 and 15%) of ground flaxseed vs. whole flaxseed. Storing eggs for 6 wk caused significant reduction in texture and off-flavor of all eggs tested in Trial 1 regardless of source of Ω-3 fatty acid incorporation. In Trial 2 consumer panelists showed a preference in appearance of eggs from hens fed the golden (Omega) vs. brown (Neche) variety of flax. Thiobarbituric acid reactive substances (TBARS) significantly decreased with storage time in both Trial 1 and Trial 2, indicating that less active oxidation occurred in eggs during cold storage. TBARS were not consistently affected by level of dietary flaxseed. Yolks produced on the golden variety of flaxseed also had lighter color. Overall acceptability of eggs from flax-fed hens was similar to that of eggs from diets enriched with menhaden fish oil and not greatly different from that of regular eggs.