Conventional Eggs Research Articles

Egg authentication under seasonal variation using stable isotope analysis combined with machine learning classification

In the European Union (EU) eggs from laying hens are sold in different husbandry systems: enriched cage, barn, free-range and organic. An analytical distinction between the husbandry systems is of interest for the food control authorities, as fraudsters can make high profits by mislabelling the husbandry system of the eggs. In this study, a total of 180 hen's egg samples labelled to originate from barn, free-range and organic hens were taken from food retailers in Germany at monthly intervals over a period of 15 months. The eggs were analysed using stable isotope ratio analysis (IRMS) in order to identify potential influences of different husbandry methods. The analysis on a monthly basis showed that the feeding of the laying hens varied over the year, which makes it difficult to make a clear classification according to the type of husbandry. Temporary events such as the officially ordered poultry quarantine due to the avian influenza, had minor influence on the differentiation of the husbandry types. Various statistical models including linear discriminant analysis (LDA), random forest (RF) and multinomial logistic regression (Multinomial) based on a multi-element approach (δ13C, δ15N, δ34S) were used to classify the eggs according to the three types of husbandry. On average, the models achieved a correct classification of approximately 70%. The reduction of the prediction model to two classes (organic vs. conventional eggs) led to a correct classification of almost 80% across all samples. Additionally, significant differences in the mean values of the sulphur isotopes of the organic eggs showed a regional differentiation between Bavaria (southern Germany) and Schleswig-Holstein (northern Germany).

Investigation into the Sensory Properties of Plant-Based Eggs, as Well as Acceptance, Emotional Response, and Use.

Consumers have become interested in plant-based alternatives to animal-based products. One of the under-studied alternatives is plant-based eggs (PBEs). This research investigated PBEs relative to conventional eggs and tofu scramble-another plant-based alternative. Firstly, participants (n = 93) completed a word association task asking them about PBEs. Participants then evaluated the different food samples using hedonic scales, check-all-that-apply (CATA), and temporal check-all-that-apply (TCATA), as well as identified their emotional response and proposed use for PBEs. Participants were interested in plant-based alternatives, including PBEs, but they were concerned about the sensory properties. When they evaluated the different samples, the flavour and texture of the PBEs were disliked in comparison to the eggs. This result may be due to the beany, bitterness, and off-flavour attributes associated with the PBEs. Participants also associated the PBEs with negative emotions. The liking of tofu scramble was not significantly different from the eggs, and the eggs and tofu scramble were mainly associated with positive emotions. During the TCATA evaluation, the participants focused on the flavour attributes of PBEs, while their evaluation of the eggs was dominated by the textural attributes. Whether following a plant-based diet or not, consumers are interested in PBEs, but the sensory properties of PBEs need to be improved before they are willing to adopt them into their diet. This study is one of the first to evaluate the sensory properties of PBEs, as well as consumers' emotional response to them and their attitudes about PBEs.

N-3 PUFA Enriched Eggs as a Source of Valuable Bioactive Substances.

This research elaborates the process of enriching table eggs with n-3 polyunsaturated fatty acids (n-3 PUFA) and presents the effect of such enriched eggs on human health. The experiment was performed on 480 TETRA SL laying hens divided into three groups. Feeding mixtures contained 5% of oils (K = soybean oil, P1 = 3.5% linseed oil + 1.5% fish oil, P2 = 3% linseed oil + 2% fish oil). Referring to the content of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), eggs of P1 and P2 groups were significantly richer in n-3 PUFA than eggs of the control group (p = 0.001). Atherogenic (AI), thrombogenic (TI), and hypo/hypercholesterolemic (HHI) indexes of egg yolks were more favourable in enriched eggs than in conventional eggs. Fatty acid profiles in the blood of examinees that consumed conventional and enriched eggs (treatments K and P1, respectively) differed significantly in total saturated fatty acids (ΣSFA) (p = 0.041) and in the content of ALA (p = 0.010). The consumption of n-3 PUFA-enriched eggs lowered the Σn-6 PUFA/Σn-3 PUFA ratio in the examinees' blood serum (27%) and had a favourable effect on some blood biochemical indicators. This research confirmed the assumption that the use of a combination of fish and linseed oil in mixtures for laying hens in an amount of up to 5% will increase the content of omega-3 in table eggs, but it was not confirmed that the consumption of these eggs in a short period of time (21 days) has a positive effect on human health.

Constraints faced in distribution and retailing of conventional eggs in Hyderabad district of Telangana

Constraints faced in distribution and retailing of conventional eggs in Hyderabad district of Telangana

Comparative Analysis of LC-ESI-IM-qToF-MS and FT-NIR Spectroscopy Approaches for the Authentication of Organic and Conventional Eggs.

The importance of animal welfare and the organic production of chicken eggs has increased in the European Union in recent years. Legal regulation for organic husbandry makes the production of organic chicken eggs more expensive compared to conventional husbandry and thus increases the risk of food fraud. Therefore, the aim of this study was to develop a non-targeted lipidomic LC-ESI-IM-qToF-MS method based on 270 egg samples, which achieved a classification accuracy of 96.3%. Subsequently, surrogate minimal depth (SMD) was applied to select important variables identified as carotenoids and lipids based on their MS/MS spectra. The LC-MS results were compared with FT-NIR spectroscopy analysis as a low-resolution screening method and achieved 80.0% accuracy. Here, SMD selected parts of the spectrum which are associated with lipids and proteins. Furthermore, we used SMD for low-level data fusion to analyze relations between the variables of the LC-MS and the FT-NIR spectroscopy datasets. Thereby, lipid-associated bands of the FT-NIR spectrum were related to the identified lipids from the LC-MS analysis, demonstrating that FT-NIR spectroscopy partially provides similar information about the lipidome. In future applications, eggs can therefore be analyzed with FT-NIR spectroscopy to identify conspicuous samples that can subsequently be counter-tested by mass spectrometry.

Natural Multi-Enriched Eggs with n-3 Polyunsaturated Fatty Acids, Selenium, Vitamin E, and Lutein.

The research investigates the possibilities of enriching eggs with n-3 polyunsaturated fatty acids, selenium, vitamin E, and lutein. The research was carried out on 100 TETRA SL laying hens divided into two groups (C and E). Hens in treatment C (control group) were fed a standard feeding mixture that contained 5% soybean oil, 0.32 mg/kg organic selenium, 25.20 mg/kg vitamin E, and 20.5 mg/kg lutein (Marigold flower extract). Hens in treatment E (experimental group) were fed a mixture in which soybean oil was replaced by 1.5% fish oil + 1.5% rapeseed oil + 2.0% linseed oil. The content of other nutricines amounted to 0.47 mg/kg organic selenium, 125.2 mg/kg vitamin E, and 120.5 mg/kg lutein. Portions of total n-3 polyunsaturated fatty acids in enriched eggs were significantly increased when compared to conventional eggs (480.65:204.58 mg/100 g; p < 0.001). The content of selenium, vitamin E, and lutein was significantly higher (p < 0.001) in enriched eggs than in conventional eggs. The content of selenium in egg albumen was increased by 1.81 times, and in the yolk, it was increased by 1.18 times. At the same time, the content of vitamin E was 2.74 times higher, and lutein was 8.94 times higher in enriched eggs than in conventional eggs.

Monitoring antimicrobial residues in table eggs in Aswan governorate markets and their impact on egg quality and public health.

Organic egg is among the most common organic foods offered for sale in Egyptian markets in recent years, and consumers buy them at a higher price because they believe organic eggs are safer and have superior nutritional value than conventional eggs. The present work aimed to monitor antimicrobial residues in brown table eggs, whether conventional or organic type, in Aswan governorate markets and assessed their physical and chemical quality and their public health hazards. Brown table egg samples (n = 400 total) were randomly selected in the present study, in which they represented two equal groups (n = 200 each) including conventional eggs and organic eggs. Eggs were collected from different retail stores in the Aswan governorate, Egypt. Egg samples were subjected to thorough physical and chemical quality evaluation as well as an assessment of antimicrobial residues. The results reported that organic eggs were cleaner and had a better odor, less blood, and meat spots, but smaller with more shell cracks than conventional eggs. Chemical analysis of some nutrient contents in the egg yolk revealed significantly higher nutritive values of organic eggs than that of conventional ones as the organic eggs contain significantly higher levels of vitamin A and vitamin D/D3 and significantly lower values of cholesterol, calcium, magnesium, and zinc than those in conventional eggs. Disc diffusion assay has been used for monitoring antimicrobial residues in egg samples. The results have shown that all examined organic eggs were free from antimicrobial residues, while 12% and 8% of conventional egg yolk and white were positive for antimicrobial residues, respectively. The study concludes the higher nutritive value of organic eggs compared with the conventional type because of their significantly higher contents of vitamins A and D and their significantly lower contents of cholesterol. Moreover, organic eggs were free from antimicrobial residues which maximizes their public health benefits..

Determination of vitamin D level in chicken eggs from conventional and free range systems

This study aimed to investigate the vitamin D levels and some quality features of eggs. A total of 150 eggs (75 conventional and 75 free-range) were selected for the study. The levels of 25-OH vitamin D were determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in egg yolks. Furthermore, we evaluated the weights of egg, yolk, albumen, and yolk color as well as shape index, shell thickness, and percentages of albumen, yolk, and shell. The 25-OH vitamin D levels were significantly higher (P < 0.01) in the conventional than in the free-range eggs. Furthermore, the weights of egg, albumen, yolk, percentage of yolk and yolk color were significantly higher (P < 0.01) in the conventional than in the free-range eggs. However, the shape index, percentage of albumen, percentage of shell and shell thickness were significantly higher (P < 0.01) in the free-range than the conventional eggs. It can be concluded that vitamin D levels in eggs can be related to yolk color. However, egg quality characteristics can also be influenced by various environmental factors.

Preferência do Consumidor e Características de Qualidade em Ovos de Diferentes Categorias Comercializados nos Supermercados do Rio de Janeiro

ABSTRACT This study approached the consumer preference and characteristics of eggs from various categories sold at supermarkets in Rio de Janeiro. The study was performed in three phases. In the first one, 180 'caipira' eggs were randomly acquired from three supermarkets considering the consumers’ socioeconomic profile (middle, upper, and lower class). In the second phase, 456 eggs from conventional, free-range, 'caipira' and omega-3 enriched categories were obtained without considering the socioeconomic condition. After the acquisition, the eggs were taken for further analyses made the next day. The last phase was based on the perception and prevalence of consumers found in the second stage. This time, 443 consumers answered a Google Forms questionnaire. 'Caipira' eggs sold at supermarkets frequented by upper-class consumers maintained a better quality. When social class was discarded as a criterion, eggs from 'caipira', free-range, organic, and omega-3 enriched systems showed inferior quality compared to conventional eggs. The consumer preferences indicated that much misinformation regarding technical aspects of egg production persists, despite the increasing consumption of this protein source. In addition, the study revealed that many consumers still think there are hormone inputs in poultry farming, and they know very little about the production process or the differences among the egg categories for sale at Brazilian supermarkets.

A new method for determining PFASs by UHPLC-HRMS (Q-Orbitrap): Application to PFAS analysis of organic and conventional eggs sold in Italy

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental pollutants with the ability to uptake to food and feed. Among food, fish, fruits and eggs are considered as major contributors to human dietary exposure. A new method was developed and validated for the simultaneous determination of 18 PFASs in eggs using isotope dilution followed by ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry. The analysis of 132 samples (organic, barn and caged eggs) was performed. Levels were always close to the detection limits and no significant difference emerged among the 3 groups. The highest PFAS concentration in eggs was used to estimate the dietary exposure of different Italian population groups. As expected, children were more highly exposed than adults due to lower body weight. This data suggests that the recent tolerable weekly intake of 4.4 ng kg-1b.w. could be exceeded when the cumulative intake arising from other food products is considered.

Organic Egg Consumption: A Systematic Review of Aspects Related to Human Health.

Consumption of organic foods has increased recently, but evidence about their potential health benefits is still limited. This systematic review aims to synthesize the available scientific evidence on the association between organic egg consumption and human health. We searched for peer-reviewed articles on this subject indexed in the MEDLINE, EMBASE, Web of Science and Cochrane Library databases from the inception date to April 13, 2022. This review was based on PRISMA guideline recommendations. Three studies on organic egg consumption in humans were included. After 8 weeks of consuming organic eggs, one randomized crossover trial found that participants had higher serum concentrations of the beta-carotene lutein compared to the period without consuming organic eggs. Moreover, in a cross-sectional study with nationally representative data from Americans over the age of 50, it was found that consumption of organic eggs was associated with lower levels of the inflammatory markers C-reactive protein and cystine C compared with conventional eggs. Finally, in a cohort of children aged 0 to 2 years, no significant association was observed between consuming organic eggs and the risk of eczema. In conclusion, the evidence about the potential benefits of organic egg consumption and human health is promising but still requires further research. A human research agenda is proposed based on laboratory studies pointing out that organic eggs have a more desirable nutritional profile than conventional eggs.

Discriminant Analysis of the Nutritional Components between Organic Eggs and Conventional Eggs: A 1H NMR-Based Metabolomics Study.

The difference of nutrient composition between organic eggs and conventional eggs has always been a concern of people. In this study, 1H nuclear magnetic resonance (NMR) technique combined with multivariate statistical analyses was conducted to identify the metabolite different in egg yolk and egg white in order to reveal the nutritional components information between organic and conventional eggs. The results showed that the nutrient content and composition characteristics were different between organic and conventional eggs, among which the content of glucose, putrescine, amino acids and their derivatives were found higher in the organic eggs yolk, while phospholipids were demonstrated higher in conventional eggs yolk. Organic acid, alcohol, amine, choline and amino acids were higher in conventional eggs white, but glucose and lactate in organic egg were higher. Our study demonstrated that there are more nutritive components and higher nutritional value in organic eggs than conventional eggs, especially for the growth and development of infants and young children, and conventional eggs have more advantages in promoting lipid metabolism, preventing fatty liver, and reducing serum cholesterol. Eggs have important nutritional value to human body, and these two kinds of eggs can be selected according to the actual nutrient needs.

Differentiation of eggs from organic and conventional production systems using fluorescence excitation spectroscopy (FES)

ABSTRACT The decay curves of the delayed luminescence of egg yolks after excitation with white, yellow and blue light were investigated, using fluorescence excitation spectroscopy (FES), and the relationships to the origin of the eggs were examined. FES measurements were done by exciting the sample with light of defined wavelengths, representing the colours white (w), blue (bl) and yellow (ye), and the subsequent photon emission was detected. A total of 147 samples (each sample consisted of 10 eggs) were analysed, which originated from samples collected directly from the farm as well as from retail markets. Classification by partitioning and Tukey HSD tests were used to show differences between the origin of the eggs. It was shown that the induced emission of the conventional eggs was different compared with that of the organic eggs, which was reflected especially in the long-time emission parameters R40-w and R80-ye/bl, with lower values for conventional samples. Classification was possible with the parameters R40-w and R80-ye/bl, allowing correct classifications of 91.8% and 95.9% of the samples, respectively.

Cholesterol Content and Fatty Acids Profile in Conventional and Omega-3 Enriched Eggs

This study aimed to produce table eggs enriched with n-3 polyunsaturated fatty acids by diet modification and at the same time, determine the fatty acid profile and cholesterol content in egg yolk, and compare them with that of conventionally produced eggs. Eighty laying hens of Tetra SL hybrids were allocated into two experimental groups. The diets were balanced at the level of 11.60 MJ/kg ME and 16.63% crude protein. The experiment lasted 5 weeks. In the n-3 PUFA eggs, yolk cholesterol levels were 1179.25 mg/100 g compared to the 1287.46 mg/100 g measured in the control eggs. The difference of 108.21 mg/100 g i.e. 8.4% was not statistically significant (p>0.05). The fatty acid profile in n-3 PUFA versus control eggs was as follows: SFA 30.55 vs 35.89% (p<0.001), MUFA 42.61 vs 42.28%, n-6 PUFA 22.10 vs 21.40% (p>0.05), and n-3 PUFA 4.74 vs 0.82% (p<0.001). Furthermore, ALA content was 2.28 vs 0.26%, EPA 0.31 vs 0.14%, and DHA 2.20 vs 0.43% (p<0.001) in n-3 PUFA vs control eggs, respectively. The n-6/n-3 PUFA ratio in the enriched eggs was 5.11 and in the conventional ones 23.73 (p<0.001). Based on the results of our study, it can be concluded that in n-3 PUFA-enriched eggs, the n-6/n-3 PUFA ratio is significantly improved compared to the conventional eggs. Thus, n-3 PUFA eggs are nutritionally and functionally more favorable than conventional eggs for human nutrition.

Profiling of Essential Mineral Content, Heavy Metals, and Bacterial Contaminants in Conventional and Organic Eggs Available in the Hypermarkets of the Eastern Province of Saudi Arabia

Eggs are commonly regarded as one of the best sources of various macro and micronutrients, in particular, high biological value (BV) proteins and both saturated and unsaturated fatty acids. Apart from proteins, eggs are excellent sources of various high health value lipid components, carotenoids, minerals, and both water and lipid-soluble vitamins. However, the nutrient-rich nature of this 'superfood' also makes them susceptible to microbial contamination from various sources, such as fecal matter, drinking water for layer chicken, and the surrounding environment. Moreover, drinking water and chicken feed are also sources of heavy metal contamination. The presence of both factors poses serious health concerns for consumers. The main aim of this research was to proximate heavy metals and bacterial contaminants in nine different brands of brown organic and conventional white eggs available in the hypermarkets of the Eastern Province of Saudi Arabia. An Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) was used to determine the concentration of metals with high sensitivity. Standard plate count was followed by enrichment of bacterial contaminants in a double-strength nutrient broth medium for microbiological assessment. The results indicated that Pb, Cd, Al, and As were present in high concentrations in all egg brands of both types (organic and conventional). The estimated daily intake (EDI) values for Ca, Fe, Mn, and Mg were within the range of WHO-recommended thresholds, and these essential minerals were present in adequate amounts in all egg brands. The two major groups predominating the microbial loads were the family Enterobacteriaceae and Pseudomonas sp. The presence of heavy metals, such as Al, As, Pb, and Cd, in nearly all the brands in amounts that exceeded the established ADI and EDI thresholds was considerably concerning. In particular, the elevated levels of Cd and Pb in group 1 and group 2A probable human carcinogens, respectively, demands that local regulatory authorities investigate the sources of heavy metal contamination and alleviate this considerable risk to human health. Furthermore, this study could be a benchmark for establishing food safety and hygiene standards for local egg production, storage, handling, and transport in Saudi Arabia.

Impact of Different Layer Housing Systems on Eggshell Cuticle Quality and Salmonella Adherence in Table Eggs.

The bacterial load on the eggshell surface is a key factor in predicting the bacterial penetration and contamination of the egg interior. The eggshell cuticle is the first line of defense against vertical penetration by microbial food-borne pathogens such as Salmonella Enteritidis. Egg producers are increasingly introducing alternative caging systems into their production chain as animal welfare concerns become of greater relevance to today’s consumer. Stress that is introduced by hen aggression and modified nesting behavior in furnished cages can alter the physiology of egg formation and affect the cuticle deposition/quality. The goal of this study was to determine the impact of caging systems (conventional, enriched, free-run, and free-range), on eggshell cuticle parameters and the eggshell bacterial load. The cuticle plug thickness and pore length were higher in the free-range eggs as compared to conventional eggs. The eggshells from alternative caging (enriched and free-range) had a higher total cuticle as compared to conventional cages. A reduction in bacterial cell counts was observed on eggshells that were obtained from free-range eggs as compared to the enriched systems. An inverse correlation between the contact angle and Salmonella adherence was observed. These results indicate that the housing systems of layer hens can modify the cuticle quality and thereby impact bacterial adherence and food safety.

Impact of feed glyphosate residues on broiler breeder egg production and egg hatchability

Glyphosate is the active substance in glyphosate-based herbicides, e.g. Roundup. Its widespread application on feed crops leaves residues in the feed. Glyphosate has antimicrobial and mineral chelating properties and we investigated whether there is an association between feed residues of glyphosate on the one side and broiler breeder egg laying percent and egg hatchability on the other side. Twenty-six feed samples from five conventional flocks producing hatching eggs were analysed for glyphosate. Data on laying percent and egg hatchability from periods following each feed sampling were then associated with feed residues of glyphosate. The average glyphosate residue level was 0.09 mg/kg, maximum was 0.19 and minimum was 0.004 mg/kg. Average laying percent over observation days was 65% (SD = 5.4%) and average hatchability was 79% (SD = 5.8%). We found a negative association between feed glyphosate residue level and hatchability (P = 0.03) when adjusted for breeder age, storage time of eggs on farm before delivery and storage time at hatchery before incubation start. No association was found with laying percent (P = 0.59) adjusted for breeder age. The range of glyphosate concentrations in feed was narrow and should be kept in mind when interpreting both significant and non-significant associations with glyphosate residue concentrations. In nine of 24 analysed conventional eggs the concentration of glyphosate in yolk was above the detection limit however below the quantification limit indicating that traces of glyphosate are common in conventional eggs.

Does online chatter matter for consumer behaviour? A priming experiment on organic food

AbstractConsumers are increasingly sharing their opinions on societal issues and products online. We studied the implications of such online word‐of‐mouth for consumer judgement and decision‐making. The case used is organic food, which is the most successful among the currently emerging, sustainability‐differentiated food product categories. We first analysed the online discussion on organic food by conducting a text‐mining study of reader comments (N = 63,379) from the comments section of a major German online news outlet. Topics therein are discussed with differing frequency, thereby indicating the salience of the various issues to online readers and consumers. One organic food topic of high salience (animal welfare) and one of low salience (biodiversity) were selected to investigate the behavioural relevance of salient online topics in a subsequent priming experiment (online survey of German consumers; N = 1,118). In particular, we tested whether the relative online salience of the two topics used as primes influenced the likelihood of choosing organic instead of conventional eggs and milk in a choice experiment and the acceptance of policies supporting organic farming. Although ineffective for the choice of milk, the priming worked as hypothesized regarding the choice of eggs and policy acceptance. Priming the topic with high online salience is more effective at promoting pro‐organic behaviour than priming the topic with low online salience. Priming effects also depended on prime strength, attitude strength and experience with buying organic food. We discuss how insights from text mining of online word‐of‐mouth can be employed to promote sustainable consumption behaviour.

Exploring consumers’ perceptions of plant-based eggs using concept mapping and semantic network analysis

Plant-based eggs offer a healthy, animal-free, and more environmentally sustainable alternative to conventional eggs. Given the novelty of these products, it is vital to understand consumers’ perceptions before their market launch. Perception is based on product associations stored in consumers’ memory as semantic networks. In this study we used the graphic procedure concept mapping to elicit associations of 180 consumers from the UK and Italy to explore perceptions of three types of plant-based eggs, namely liquid, powder, and egg-shaped. Concept mapping also allowed to investigate the relevance that these associations have for the consumers. Results show more complex associations among participants in the UK than Italy for all three types of plant-based eggs. ‘Price’ is the most frequently mentioned association by consumers in both countries. In terms of relevance, participants evaluated ‘healthy’, ‘animal welfare’ and ‘sustainability’ as the most important and positive attributes of plant-based eggs. Furthermore, the semantic network analysis showed that the health benefits of plant-based eggs is quickly activated in consumers’ mind and should therefore be emphasized when marketing these products. ‘Use’ of plant-based eggs, e.g., baking, is also a key association, particularly in the UK for the egg-shaped version. However, ‘use’ was generally lower rated, suggesting that the limited applications of this product (only hard-boiled) may be perceived negatively. These findings provide insights into the psychology of consumers’ acceptance of plant-based eggs and have important implications for designing successful marketing strategies for promoting plant-based eggs.

Plant-based Eggs: Views of Industry Practitioners and Experts

Plant-based eggs have been recently developed by food practitioners as an alternative to conventional eggs. However, there is uncertainty on how the current egg market will react to plant-based eggs, as well as lack of knowledge about product development and regulations. In this manuscript, we explored this issue by conducting in-depth interviews with egg industries and retailers, as well as with plant-based egg manufacturers. Results show that despite egg manufacturers are struggling to provide an alternative to people who do not consume eggs, they are skeptical that plant-based eggs can replicate all eggs’ nutrients and functionalities. Furthermore, egg industries do not see plant-based eggs as potential competitors to their products, while plant-based egg manufactures argue that they will directly compete with eggs. Also, there is uncertainty on how to label and name plant-based eggs, which has important implications in terms of marketing and policy labeling of these new products.