Consumer behaviour, perceptions, and preferences towards eggs: A review of the literature and discussion of industry implications

Partial budget analysis of laying hens' transition from cages to production systems of improved welfare: a case study in Greece

1. In recent years, public concern regarding animal welfare has increased while, at the same time, cage systems for animal production have been greatly criticised by EU citizens. In addition, large food retailers promote food products that are made with eggs produced in cage-free systems.2. The objective of this study was to evaluate the economic viability of the transition of laying hens' to production systems; from conventional to alternative systems with improved welfare. Three independent scenarios were assumed as follows: transition from enriched colony cages to barn (S1), transition from barn to free-range (S2), and transition from free-range to organic (S3). Economic assessments of each transition was applied to a model farm in Greece with 12 000 hens, through partial budget analysis and net benefits and costs were estimated.3. The results showed a positive economic impact in all transitions to a production system of improved animal welfare (€12,044 in S1, €18,957 in S2 and €7,977 in S3) which indicated that they are economically sustainable. In all scenarios, unit cost increased by 19% in S1, 12% in S2, and 85% in S3.4. In conclusion, transitioning towards improved animal welfare production systems in laying hen farms could be an economically viable option for egg producers in compliance with societal demands and market trends.

Whole transcriptome sequencing reveals key genes and ceRNA regulatory networks associated with pimpled eggs in hens

Eggshell is one of the most important indicators of egg quality, and due to low shell strength, pimple eggs (PE) are more susceptible to breakage, thus causing huge economic losses to the egg industry. At the current time, the molecular mechanisms that regulate the formation of pimple eggs are poorly understood. In this study, uterine tissues of PE-laying hens (n = 8) and normal egg (NE) -laying hens (n = 8) were analyzed by whole transcriptome sequencing, and a total of 619 differentially expressed mRNAs (DE mRNAs), 122 differentially expressed lncRNAs (DE lncRNAs) and 21 differentially expressed miRNAs (DE miRNAs) were obtained. Based on the targeting relationship among DE mRNAs, DE lncRNAs and DE miRNAs, we constructed a competitive endogenous RNA (ceRNA) network including 12 DE miRNAs, 19 DE lncRNAs, and 128 DE mRNAs. Considering the large amount of information contained in the network, we constructed a smaller ceRNA network to better understand the complex mechanisms of pimple egg formation. The smaller ceRNA network network contains 7 DE lncRNAs (LOC107056551, LOC121109367, LOC121108909, LOC121108862, LOC112530033, LOC121113165, LOC107054145), 5 DE miRNAs (gga-miR-6568-3p, gga-miR-31-5p, gga-miR-18b-3p, gga-miR-1759-3p, gga-miR-12240-3p) and 7 DE mRNAs (CABP1, DNAJC5, HCN3, HPCA, IBSP, KCNT1, OTOP3), and these differentially expressed genes may play key regulatory roles in the formation of pimpled eggs in hens. This study provides the overall expression profiles of mRNAs, lncRNAs and miRNAs in the uterine tissues of hens, which provides a theoretical basis for further research on the molecular mechanisms of pimpled egg formation, and has potential applications in improving eggshell quality.

Suppliers' Perspectives on Cage-Free Eggs in China

Successful promotion of cage-free eggs supports a housing system offering potential for improved hen welfare. As the world's largest egg producer and consumer, China offers much potential for welfare improvements. We examined 10 Chinese companies supplying cage-free eggs (four using indoor systems, six with outdoor access) to understand their strategies to promote cage-free eggs to businesses and consumers. We purposively sampled 12 employees from these companies familiar with production or sales. We conducted two-three semi-structured interviews per participant, collected public online documents (including online shops and social media content), and recorded field notes. We analyzed the data using template analysis to generate key results. Participants reported buyers being unfamiliar with 'animal welfare' and 'cage-free', but familiar with concepts associated with 'free-range'. Participants considered three attributes when promoting cage-free eggs: price (engaging buyers who were willing to pay more), experiential attributes (e.g., taste, accommodating buyer preferences), and non-sensory credence attributes (e.g., cage-free production, improving buyers' understanding and trust). Our results are not generalizable, though they may be transferable to similar contexts. Understanding how companies promoted cage-free eggs to buyers may help inform promotion of other animal products with welfare attributes. Simultaneous efforts are needed to ensure actual welfare improvements on farms.

Analysis of the Quality and Chemical Composition of Double-Yolked Eggs Compared to Those of a Normal Structure

The study material consisted of 360 eggs from a reproductive flock of meat-type hens; 240 were double-yolked eggs and 120 were single-yolked as a control group. The eggs were numbered individually and then analysed for their quality in terms of characteristics of the whole egg (weight, shape index, specific gravity), shell (colour, strength, weight, density), albumen (pH, height, weight, Haugh units) and yolk (colour, weight, shape index, pH). During the analyses, yolks were sampled for analyses including basic composition, fatty acid profile (by gas chromatography) and fatty acid indices. It was found that double-yolked eggs differed significantly from single-yolked ones in terms of weight, proportion of individual elements in the egg weight, total protein content in the yolks as well as in terms of the fatty acid profile and their indices both due to the presence or absence of two yolks and in the context of the individual yolks analysed. The results indicate the possibility of using double-yolked eggs as table eggs due to the absence of negative effects stemming from being double-yolked and the increased content of biologically important components such as fatty acids.

Evaluation and Discrimination of Lipid Components and Iron and Zinc Levels in Chicken and Quail Eggs Available on the Polish Market

All over the world, birds' eggs are an important and valuable component of the human diet. This study aimed to compare the content of lipid components and their nutritional value as well as iron and zinc levels in chicken and quail eggs commonly available on the market. In egg lipids, unsaturated fatty acids were dominant, especially oleic acid, the content of which was about 40% of the total fatty acids (TFAs). Linoleic acid was the major polyunsaturated fatty acid. Compared to other products of animal origin, eggs were characterized by favorable values of lipid quality indices, especially the index of atherogenicity, thrombogenicity, and the hypocholesterolemic-to-hypercholesterolemic ratio. In the present study, no differences were found in the content of tested nutrients between eggs from different production methods (organic, free-range, barn, cages). Based on linear discriminant analysis, inter-breed differences were noticed. Cluster analysis showed that eggs enriched in n3 PUFAs (according to the producers' declarations) differed from other groups of chicken eggs. However, in eggs from one producer only, the amount of EPA and DHA exceeds 80 mg per 100 g, entitling the use of the nutrition claim on the package. Quail eggs differed from chicken eggs in FA profile and cholesterol and iron levels.

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.

Knowledge and handling practices for raw hen's eggs during purchase, preparation, storage, and consumption: a cross sectional study

The study aimed to assess the hen's eggs knowledge, handling practices, and consumption among Palestinian consumers using the cross-sectional survey design. Online questionnaire was sent via social media platforms including well-known Facebook and WhatsApp groups in West bank, Gaza and Jerusalem, along with an invitation explaining the research objectives and the voluntary participation. The online questionnaire consisted of three main sections: socio demographic, knowledge and practices for hen's eggs during purchase, preparation, storage, and consumption. The items were developed based on previous literature and international guidelines for hen's eggs purchase and handling, and subjected to content validity process, followed by a pilot study to determine the reliability of the questionnaire using Cronbach's alpha test. The final data were analysed based on the dichotomous Rach model for knowledge and polytomous Rasch model for practices using Winsteps version 5.1.3. The Rasch SPSS output interval data files were used in the inferential analyses tests (one-way ANOVA test and independent samples t-test). The Rasch analysis showed that on average the participants had quite low level of knowledge of hen's eggs consumption safety, (person ability Mean 0.10 logit). The item difficulty measures ranged between + 1.65 (most difficult) and - 2.24 logit (easiest). It was not easy for the participants to endorse the items pertaining their practices in handling the hen's eggs during purchase, preparation, storage and consumption, (person ability Mean - 0.11 logit). The item difficulty measures ranged between + 2.68 logits (most difficult) to - 2.45 logit (easiest). In addition, female participants significantly outperformed males in knowledge scores; and the level of hen's eggs hygiene practices and storage during purchase depended on participants' knowledge level. The research recommended interventional programs to enhance Palestinians' awareness and knowledge about hen's eggs knowledge, handling practices, and consumption. Further quantitative and qualitative research studies were also recommended.

Dietary survey of poultry egg intake among residents in Kunming city, southwest China

Background

For almost all people, eggs can be a wholesome addition to the diet. However, there is insufficient applicable data to evaluate the poultry egg intake of people in the city of Kunming located in southwest China.

Objectives

To understand the situation of egg consumption among local residents in Kunming via a dietary survey.

Methods

Residents living in three places of Kunming were chosen using a multi-stage random sampling method. The recall methods of 3-day food intake and 1-month food intake frequency were used to assess the quantity and frequency of poultry egg dietary intake of local people.

Results

Of the 1,118 respondents, 565 (50.54%) were female and 553 (49.46%) were male with age range 0.5-91 years old. Egg consumption was widespread among the survey respondents with 88.01% reporting hen egg ingestion, but the dietary intake of other poultry eggs such as duck, quail, and goose eggs were much less frequent. The medium daily intake of hen eggs was 20.00 g/d with greater amount of hen egg consumption in older age groups. However, when calculated on a body-weight basis, the median amount of hen eggs consumed daily per kilogram of body weight for all survey respondents was 0.47 g/kg/d whereas this indicator for children was 1.33 g/kg/d, becoming the greatest among all age groups.

Conclusions

Our study obtained a better understanding of poultry egg intake among residents in Kunming city and calculated the egg intake kilogram of body weight that can be a useful reference to inform the development of more accurate dietary recommendation. These results also provide basic data for nutrition monitoring and dietary exposure risk assessment of poultry egg intake.

Variation in litter occupancy and dust bathing patterns among layer strains following periods of litter restriction

Producers are moving toward cage-free systems to house laying hens. These include aviary styles with multilevel wire enclosures and litter areas on the floor. In aviaries with doors hens can be confined within the tiered enclosure, which can be done to promote oviposition in nests and prevent hens from laying eggs in litter. However, there are multiple genetic strains of laying hen used in the egg industry, and some show different temporal patterns for key behaviors that could affect when they want to be on litter. For example, though dust bathing by laying hens is typically considered to peak in early afternoon, there may be variation in timing of motivation to dust bathe among strains. Differences in hens' temporal patterns, coupled with aviary configurations or management practices, may restricts birds' ability to perform important behaviors, such as dust bathing (DB), when they would most prefer to do them. Our objective was to determine if there were strain differences in the temporal pattern of DB. We examined the timing of DB in 4 strains of laying hen (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and Hy-Line W36 [W36]) housed in aviaries using 144 hens of each strain per aviary unit (4 units/strain). We recorded the number of hens DB and on litter using instantaneous scan sampling every 5 min using video collected at 26 and 28 wk of age beginning at 11:35 (when litter access began each day) to 20:00 (lights off). Brown strains acclimated to litter access more slowly than white strains. Hens of all strains DB most often soon after gaining access to litter, and more white hens (DW and W36) DB simultaneously and in the presence of more conspecifics. Further examination of diurnal rhythm of behaviors, such as dust bathing, under unconstrained conditions by a range of genetic strains of laying hens is needed to design management practices and aviary styles that best meet hens' needs.

A Preliminary Investigation of Salmonella Populations in Indigenous Portuguese Layer Hen Breeds

The sustainability of agroecological systems, biodiversity protection, animal welfare, and consumer demand for higher quality products from alternative and extensive farming methods have reinforced interest in local breeds that are well adapted to low-input environments. However, food safety needs to be safeguarded to reinforce consumer confidence. The aim of this study was to conduct a preliminary investigation on the occurrence of Salmonella spp. in eggshells, hen's cloaca, and litter materials from autochthonous Portuguese laying hens raised in a semi-extensive system for small-scale production. A total of 279 samples from 31 flocks belonging to 12 farms were obtained, with 63 samples from the "Preta Lusitânica" breed, and 72 samples each from the remaining autochthonous breeds, namely, "Branca", "Amarela", and "Pedrês Portuguesa". None (0%) of the samples analyzed were positive for Salmonella spp. To the best of our knowledge, these are the first results of Salmonella evaluation from hen's cloaca, eggshells, and litter materials in autochthonous Portuguese chickens, suggesting that a semi-extensive production system can contribute to better food security and a lower risk to public health and the environment.

Research on Chinese consumers' shell egg consumption preferences and the egg quality of functional eggs

The purpose of this study is to investigate the characteristics of egg consumption in China and the production of functional eggs, and finally enrich the types of shell egg products. Trial 1 explored the influence of egg quality on Chinese consumers' willingness to purchase eggs through a questionnaire, which investigated 1,317 consumers' preferences for egg appearance, factors influencing egg purchase, and purchase of functional eggs. The results showed that about 65% of respondents ate more than 4 eggs per wk, pink eggs were the most popular in China, about 65% of consumers preferred eggs with an egg weight of 48 to 58 grams. For functional eggs, 75.32% of consumers have never heard of them. Preferences for eggshell color and yolk color varied by geographic region, with darker colors preferred in Northeast China. Based on the survey results of functional eggs consumption in Trial 1, the dwarf layers of China Agricultural University were used in Trial 2 to produce functional eggs. The eggs are small and pink in color, which is in line with the preferences of Chinese consumers. Three hundred dwarf layers were divided into 4 groups, using the linseed oil added, marigold extract added, and yeast selenium added diets to produce normal, n-3 fatty acid-enriched, lutein-enriched and selenium-enriched eggs by feeding for 28 d, determined the eggs' nutrient content and egg quality. The results showed that the n-3 fatty acid, lutein and selenium contents of the eggs of dwarf layers were significantly increased by changing the diets and did not affect the egg weight, eggshell strength, Haugh units or the proportion of egg parts. The results of this study are helpful to understand the trend of egg consumption preferences in China, and on this basis to produce functional eggs that meet the consumers' expectations.

Storage impact on egg white powder's physical and functional properties

BACKGROUND

Changes in storage temperature and time alter the functional properties of egg white powder (EWP) and determine its quality and shelf-life, finally affecting the consumer acceptance of the products made from EWP. In the present study, the EWP samples were stored at four different temperatures (-20, 4, 25 and 37 °C) for 60 days, and then the protein structural, physical and functional properties of EWP were measured and assessed further for correlation with storage conditions using heatmap.

RESULTS

The viscosity of the EWP solution increased after 30 days. Foaming ability and rheological properties increased first and then decreased compared to untreated samples with the prolonged storage time. Correlation analysis results indicated that the gel hardness, water holding capacity, foaming ability, emulsifying ability, particle size, dispersibility and viscosity of EWP were significantly related to storage time (P < 0.05). Only the gelation properties of EWP stored at 37 °C for 60 days changed significantly and were negatively related to its moisture content (P < 0.05). Additionally, the random coil content of EWP was positively correlated with particle size, moisture content, solubility and gel properties, whereas β-sheet was negatively correlated with them.

CONCLUSION

Compared to other temperatures, the functional properties of EWP were relatively stable under 4 °C. Therefore, the low temperature (4 °C) was selected as the most suitable storage temperature for EWP. The results of the present study could provide a theoretical basis for the shelf-life extension of EWP. © 2022 Society of Chemical Industry.

The eggshell defect as a factor affecting the egg quality after storage

The aim of the study was to assess the influence of shell defects on the quality of eggs after storage. The study material consisted of 1,800 brown-shelled eggs from cage rearing system which were candled on the day of laying to determine the shell quality. Eggs with the 6 most common shell defects (external crack, severe stripe marks, points, wrinkled, pimples, sandy) and eggs without defects (control group) were then stored for 35 days at 14°C and 70% humidity. The weight loss of eggs was monitored every 7 days, and the quality characteristics of whole eggs (weight, specific gravity, shape), shell (defects, strength, color, weight, thickness, density), albumen (weight, height, pH) and yolk (weight, color, pH) of 30 eggs from each group were analysed at the beginning (0 days) and after 28 and 35 days of storage. The changes resulting from water loss (air cell depth, weight loss, shell permeability) were also evaluated. The study showed that all investigated shell defects significantly influenced the characteristics of the whole egg during the storage, modifying traits such as specific gravity, water loss, shell permeability, albumen height and pH, as well as proportion, index and pH of the yolk. Furthermore, an interaction between time and the shell defects presence was found.

Evaluation of Physical Egg Quality Parameters of Commercial Brown Laying Hens Housed in Five Production Systems

This study evaluates the effect of housing environment on the egg quality characteristics of brown egg layers as many different environments are currently used in the industry. Battery cages, barren colony cages, enriched colony cages, cage-free, and free-range environments were evaluated. Overall, all egg quality measurements were affected by housing environment (p < 0.01) except for vitelline membrane strength, elasticity, and egg solids. Eggshells and yolks were lightest in barren colony cages and darkest from free-range hens (p < 0.0001). Free-range eggs were heavier than eggs from all other environments (p < 0.0001). Cage-free eggs had lower albumen height and Haugh units than other environments (p < 0.0001). Lastly, cage-free and free-range eggs had stronger eggshells than the other environments (p < 0.0001), and free-range eggs had more elastic eggshells than eggs from conventional battery cages and barren colony cages (p < 0.01). Access to the range seemed to give free-range hens different nutritional advantages, which allowed for the darker yolks and shells. Furthermore, eggs from barren colony cages seemed to exhibit more negative characteristics. Simply adding enrichments to colony cages did not improve or detract from egg quality. From this research, it appears that, as the industry moves toward extensive environments, the egg quality of brown egg layers will improve.

A Comparison of the Plumage Condition of Three Egg-Laying Poultry Genotypes Housed in Non-Cage Systems

The study covered a total of 810 hens in 3 groups (housing systems) of 270 hens each. The plumage condition of laying hens raised in various types of alternative housing systems, i.e., in deep litter (B), free-range (FR), and organic systems (O), was assessed at 20, 36, and 56 weeks of age. The indoor stocking density was 6 hens/m2. The study included hens of the native Green-legged Partridge breed (Z-11), Rhode Island Red (R-11) hens covered by a genetic resource protection program, and hybrids of Hy-Line Brown. The plumage of the head, neck, back, tail, and abdomen was assessed on a 5-point scale. The assessment of individual hens' plumage was calculated as the sum of the scores of the head, neck, back, tail and abdomen and could range from 0 (no cover) to 20 points (full plumage). The type of alternative housing system implemented and the age of the laying hens had an effect on the plumage status of all body parts assessed (p < 0.05), while the genotype had an effect on the condition of the neck, back, and tail plumage (p < 0.05). In both the FR and O systems, the plumage status was similar and superior to that in B (p < 0.05). As the age of the birds increased, the condition of the hens' plumage deteriorated. The better state of the plumage in FR and O than in B may indicate improved levels of welfare in housing systems with access to outside runs.

Does Supplementary Information Add Value to Functional Food? Evidence from a Choice Experiment in China

Establishing an effective choice architecture system enables people to improve their ability to make better food choices and encourage transformation of the food system into one that is more efficient, healthy, and sustainable. However, affecting consumer preferences by improving information supply is still a crucial issue that has not been comprehensively explored in China and many developing countries. This study aimed to identify the most effective information treatment method for increasing the likelihood of purchase and willingness to pay (WTP) for nutritionally enhanced eggs. A survey with five information treatments and a choice experiment was completed by a random sample of 2379 Chinese consumers, and the mixed logit model was subsequently applied to interpret the results. It was found that when nutritional information (NI), health benefit information (HBI), and/or market status quo information (MSQ) was presented to consumers, their utility increased. Different schemes had different effects on participants' WTP. The HBI from scientific research institution, provided in the form of leaflets, has the most significant effect on improving WTP, increasing the WTP of consumers by 31.65%. WTP for functional eggs increased similarly in response to NI and MSQ information. However, adding NI to HBI did not significantly increase the value of functional eggs, especially when the information was presented to the interviewees in the form of short videos. This research broadens the present knowledge and application of an information communication strategy by suggesting that the combination of information content, carriers, source influence consumer preference and WTP for nutritionally enhanced eggs. The results have implications for the communication practices of food enterprises to optimize their marketing strategies and improve product innovation to add more value to the functional food.

Data mining-based discriminant analysis as a tool for the study of egg quality in native hen breeds

Despite the wide biodiversity of avian species of zootechnical interest in Spain, projects aimed at characterizing these genotypes and their products are necessary. External and internal egg quality traits were measured in 819 eggs laid by hens of 10 different genotypes: White, Franciscan, Black and Partridge varieties of Utrerana, Blue Andalusian, Spanish White-Faced, Andalusian Tufted White and Black varieties, Araucana; and Leghorn Lohmann LSL-Classic lineage (commercial hybrid line) hen breeds. After multicollinearity analysis of egg quality-related traits was performed (VIF ≤ 4), major diameter, minor diameter, egg weight, and albumen height were deemed redundant explanatory variables and discarded. A stepwise discriminant canonical analysis was developed to cluster eggs across hen genotypes considering egg quality attributes. Shell a* and b* variables reported the highest discriminant power (Wilks' lambda: 0.699 and 0.729, respectively). The first two discriminant functions captured 60.48% of the variance across groups (F1: 39.36%; F2: 21.12%). Clear quality differentiation signs are evidenced for Mediterranean native breeds' eggs when compared to Leghorn's eggs. Consequently, this evidence of egg quality differentiation may favor the standardization of breed- and variety-linked distinctive products, which may open new market opportunities based on the existence of a wide spectrum of diet or culinary applications.

Assessment of Consumers' Perception of Chicken Eggs Consumption and Associated Health Implications in the Volta Region of Ghana

Background:

Rather erroneously, eggs consumption is linked to increase in plasma cholesterol content and incidents of cardiovascular diseases, cancer, stroke, or diabetes. This misconception which is more pervasive particularly in sub-Saharan Africa, has led to very low patronage of eggs intake. In this study, egg consumption patterns, desired egg characteristics, and the extent to which the perception of eggs consumption as a health risk is entrenched among consumers in the Volta Region of Ghana, were examined.

Methods:

The study used primary data for the analysis and the 2-stage sampling technique was employed. First, 5 districts (Keta, Ho, Krachi East, Nkwanta South and North Tongu) were selected and afterward, a sample was randomly selected from each of the district. A well designed and pretested questionnaires were administered to the respondents.

Results:

It was found that cheaper price and deep yellow yolk were the most persuasive parameters that motivate consumer purchase. The relationship between educational level and awareness on cholesterol types was significant. More than half of the respondents held the view that egg intake results in an increase in serum cholesterol and leads to the incidence of serious health problems.

Recommendation:

This study proves the urgent need for a concerted national public education effort to raise awareness about the nutritional and health benefits of eggs intake. Success in such awareness creation will go a long way to greatly minimize acute malnutrition in the Ghana.

The Quality of Eggs Derived from Japanese Quail Fed with the Fermented and Non-Fermented Rapeseed Meal

The most popular protein source in poultry feed mixtures is soybean. However, cheaper and more available alternative protein sources are being sought, and feed manufacturers more and more often turn their attention to the post-extraction meals of local oil plants, e.g., rapeseed. Therefore, the effect of fermented and non-fermented post-extraction rapeseed meal used as a feed additive for Japanese quails was investigated on the eggs’ quality. The study was performed on 280 females of Japanese quails fed with a mixture without rapeseed meal, with non-fermented post-extraction rapeseed meal (5%, 10% and 15%) and with fermented one (5%, 10% and 15%). During the experiment, eggs were collected from each group four times (every 4 weeks) and evaluated for their quality characteristics. The addition of 10% fermented rapeseed meal had the most beneficial effect on such eggs quality traits as egg weight, specific gravity, yolk index and color and albumen pH. However, in the majority of examined parameters, no significant differences were found between birds fed with soybean meal and those fed with fermented and non-fermented rapeseed meal (morphological elements proportions, yolk weight, albumen height and Haugh’s units, eggshell quality). This supports the thesis that the use of rapeseed meals instead of soybean meals may allow obtaining the proper quality of animal raw materials at a lower cost and with the use of local feed resources.

Commercial layer hybrids kept under organic conditions: a comparison of range use, welfare and egg production in two layer strains

Outdoor range areas provide laying hens with improved opportunities to perform natural behaviors and increase the available space per bird, however, birds are also exposed to potentially stressful factors including weather and predators. Ability to cope with challenging environments varies between different strains and must be considered to ensure good welfare. The aim of this study was to determine how suitable 2 hybrids, the Dekalb White (DW) and the Bovans Brown (BB), are for organic production with special emphasis on ranging behavior. A total of 1,200 hens were housed according to organic regulations across 12 flocks of 100 birds. Range and shelter use, effect of weather, vegetation cover, egg production and quality, and mortality were assessed in addition to a range of clinical welfare indicators. Initially a greater proportion of DW hens accessed the range. However, after approximately 2 mo, a greater proportion of BB were using the range and venturing further from the house. DW hens were more likely to use the shelters than BB hens (P < 0.001). Vegetation was also worn away to a greater extent in the BB ranges. Weather affected the proportion of hens that went outside, the distance ranged from the popholes, and shelter use. BB hens were found to have better plumage condition (P < 0.001), fewer footpad lesions (P < 0.001), fewer comb wounds (P < 0.001), and lower mortality rates (P = 0.013). Both hybrids experienced keel bone fractures, though DW hens had more at the cranial portion (P < 0.001) and BB at the caudal portion (P < 0.001). DW hens had an earlier onset of lay and higher egg production than BB hens (P < 0.001), though BB hens laid heavier eggs (P < 0.001) with thicker shells (P = 0.001). Overall, BB hens seemed to perform superiorly or equivalently to the DW hens for all variables apart from egg production. These results demonstrate the importance of considering the strain of bird selected for organic production systems in order for the birds to reap the potential benefits that are offered by outdoor access.

Consumer Preference for Nutritionally Fortified Eggs and Impact of Health Benefit Information

The potential contribution of nutritionally fortified foods to the improvement of public health has been recognized internationally; however, the extent of people’s preferences for functional foods and the influence of information intervention on consumers’ acceptance and selection of nutritious foods have not been comprehensively studied in China. The main purposes of this study are to assess Chinese consumers’ perceptions towards nutritionally fortified eggs and to explore the ways in which information about the health benefits and the international market status quo of functional eggs impacts Chinese consumers’ preferences and their willingness to pay (WTP) for nutritional fortification. Discrete choice experiments were used to elicit the preferences of 740 egg consumers from four cities in China, and a mixed logit model subsequently utilized to interpret the results. It was found that the provision of comprehensive information regarding the health benefits of trace elements and unsaturated fatty acids, as well as insight into the current market status quo, significantly improved participants’ preferences and their WTP for functional eggs. Furthermore, the heterogeneous effects of demographic and sociocultural factors on consumers’ treatment of this information were explored. It was found that the study participants with children and those with prior purchase experience exhibited a relatively stronger response to the information, while those who had expressed trust in the human health benefits of the nutritional content of functional eggs were not as sensitive as expected to the additional information. Therefore, if the government and enterprises design appropriate information treatment and nudging methods according to the current consumption characteristics of nutritionally fortified eggs, this will help to improve consumers’ purchase confidence in the health efficacy of functional food and play a positive role in promoting people’s healthy food consumption.

A Cage Is a Cage, Unless You Educate. Rhetoric Negatively Impacts Support for a Novel Housing System for Laying Hens Unless the Public Are Educated

It has been proposed that terminology on commercially available eggs can impact the manner in which the eggs are discussed and ultimately consumer support. In this paper we tested if the label of ‘furnished cage’ eggs is a barrier for its support in Australia. Furthermore, we examined if educational interventions could change support and the way furnished cages were discussed. Survey participants (n = 1,157) were recruited by a stratified random sample of Australian adults. The participants were surveyed on their demographics, attitudes toward the poultry industry and animal welfare, and their egg buying behavior. Participants were randomly assigned to one of four treatment groups; two control groups and two educational groups. Participants were shown one of three videos, the control groups were shown a video with general information about chickens, the educated groups were shown one of two almost identical videos that educated them on aspects of the egg-laying industry in Australia, and the welfare implications of different housing systems including furnished systems. The only difference between the two educational videos was the name given to the furnished housing system; one group was introduced to furnished cages, the other was introduced to furnished coops. Educated participants were more likely to support furnished eggs and discuss them more positively than the control groups. When asked to discuss their support for furnished systems, control group participants exposed to the term cage were more likely to discuss the impacts of caged environments than the other treatment groups. The study suggests any negative impacts of housing system terminology can be mitigated through educational interventions.

Consumer acceptability of plant-, seaweed-, and insect-based foods as alternatives to meat: a critical compilation of a decade of research

There is a growing criticism of meat-based products over environment, animal welfare, and public health. Meat lovers are keeping and adapting their habits, while other consumers are increasingly shifting toward meat alternatives considered as healthier and more sustainable options to replace the animal-based products. This transition gives room in the market to plant-, seaweed-, and insect-based meat products alternatives. Nevertheless, these emerging markets are still facing the challenge of consumers' acceptance and the uncertainty in terms of preferences. This paper focuses on in-depth understanding of consumer perception and acceptability of plant-, seaweed-, and insect-based meat products to get insights on their current situation and future implementation. The main factors and motives influencing the consumer perceptions toward meat alternative products are reported. Further, the consumers' motives and drivers to consume alternative products were highlighted. This review, provides a better understanding of motives and drivers of consumers' acceptance to improve the acceptability of meat alternatives, considering product and country origin of the consumers of meat alternative foods.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2036096.

The Effect of L-Glutamine on Basal Albumen and Yolk Indices, and Albumen Amino Acids Composition

Simple Summary

At present, with increased consumers’ focus on eating healthy, it is expected that egg protein content and amino acids profile are among the components of eggs that play critical roles in egg selection. Thus, this research investigated the effect dietary L-glutamine supplementation has on basal albumen and yolk indices as well as albumen protein amino acid profile. The study shows a potential role of L-glutamine supplementation for enhancing nutritional values of eggs by the decrease of albumen lipid content and the change of amino acid profile.

Abstract

The current study tested the hypothesis that 1.0% dietary inclusion of L-glutamine (Gln), an non-essential amino acid that influences protein synthesis, can improve internal egg quality, including amino acids profile. Thirty-week-old Bovans Brown laying hens in their middle laying period were assigned to one of the two experimental groups (12 replicate cages, 2 hens/cage) with Gln in the form of alpha-ketoglutarate (10 g/kg) or without Gln inclusion. The experimental period lasted for 30 wks, from the 31st to the 60th week of age of hens, when eggs were collected and selected egg quality indices were determined. Gln supplementation had no effect on albumen and egg yolk share, albumen and yolk basal indices and composition, including yolk cholesterol content. However, Gln decreased the lipid content of the egg albumen (p < 0.001), and influenced albumen amino acid profile, increasing content of asparagine (p < 0.05), phenylalanine (p < 0.05), proline (p < 0.001), tryptophan (p < 0.01), and tyrosine (p < 0.05). In conclusion, the study shows a potential role of Gln supplementation for enhancing nutritional values of eggs by lower lipid content and higher amino acid profile.

The Use of the Dynamics of Changes in Table Eggs during Storage to Predict the Age of Eggs Based on Selected Quality Traits

Simple Summary

The freshness is the most important characteristic of table eggs. EU legislation does not provide clear guidelines how to store table eggs or how to elongate their shelf life. Changes occurring in eggs after laying are a natural consequence of the passage of time, and there is no method for precise determination of “age” in a randomly chosen egg. The dynamics of changes of individual quality features of the raw material during its extended storage period of up to 35 days were determined. For this purpose, the evaluation of quality traits was performed daily, and the data thus obtained made it possible to create a multivariate mathematical model which, after further statistical processing, makes it possible to determine with high certainty (above 95%) the age of an egg on the basis of its measurable traits, both non-destructive and destructive. The study allowed us to select easily measurable egg quality traits, whose values clearly change in time. The detailed data of daily variability and methods of data statistical analysis are not only of scientific importance, but are also a useful diagnostic tool in assessing the freshness of table eggs on the basis of their quality characteristics.

Abstract

The aim of the study was to determine daily changes in some egg quality parameters, indirectly reflecting egg freshness, and to assess the possibility of predicting time from laying using mathematical methods. The study material consisted of 365 table eggs of medium (M, ≥53 g and <63 g) and large (L, ≥63 g and <73 g) weight classes (commercial stock, cage system, brown-shelled eggs) collected on the same day. Eggs were numbered individually and placed on transport trays and stored (14 °C, 70% RH). Every day, for 35 days, egg quality characteristics were analyzed (10 eggs per group). The change of traits in time was analyzed on the basis of linear and polynomial regression equations, depending on the trait. Based on model fitting, eight traits were selected as those most affected by storage time: egg weight and specific weight, Haugh units, albumen weight, air cell depth, yolk index, albumen and yolk pH. These traits, excluding those related to the weight, were then used in a multiple linear regression model to predict egg age. All regression models presented in this study were characterized by high predictive efficiency, which was confirmed by comparison of the observed and estimated values.

The influence of different production systems on dioxin and PCB levels in chicken eggs from Emilia-Romagna and Lombardy regions (Italy) over 2017-2019 and consequent dietary exposure assessment

Hen eggs from farms with different production systems (organic, free range, barn, and in cage) sited in two regions of Italy (Emilia-Romagna and Lombardy) were collected from 2017 to 2019 to monitor the levels of 17 polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and the 6 non-dioxin-like polychlorinated biphenyl indicators (ndl-PCBs). Average concentrations of PCDD/Fs (0.21 pg WHO₍₂₀₀₅₎-TEQ/g fat), PCDD/Fs + dl-PCBs (0.43 pg WHO₍₂₀₀₅₎-TEQ/g fat) and ndl-PCBs (6.41 ng/g fat) were below the maximum limits established at European level in eggs, but significantly higher amounts of PCDD/Fs and PCDD/Fs + dl-PCBs were found in eggs from free-range housing system compared to barn, cage, and organic ones. The potential dietary intake of the monitored contaminants by Italian population age groups through the consumption of locally produced eggs was also evaluated. Exposure levels to PCDD/Fs plus dl-PCBs were below the tolerable weekly intake (TWI) of 2 pg WHO₍₂₀₀₅₎-TEQ/kg bw/week recently set by the European Food Safety Authority (EFSA). However, the younger population was found to be more vulnerable than other age groups to exposure to these contaminants. Specifically, the preferential consumption of free-range eggs by infants, toddlers, and children contributed more than 30% to the TWI. The results confirm the need to continuously monitor the levels of chemical contaminants in the environment and provide a reminder of the importance of targeted intervention measures aimed to reduce their occurrence in food and feed, firstly by improving the management practices on egg-producing farms.

The Impact of Package Type and Temperature on the Changes in Quality and Fatty Acids Profile of Table Eggs during Their Storage

The aim of the study was to evaluate the possibility of reducing changes in the quality of consumer hen eggs by storing them in various package type and under various temperature conditions (room and refrigeration). The material consisted of 960 chicken eggs packed in cardboard or plastic boxes, 10 pcs in each. Half of the packages were stored at room temperature (21 °C), the rest in the refrigerator (5 °C). The eggs were stored for 28 days qualitatively evaluated at 14-day intervals. The characteristics of whole egg (weight, specific weight, proportion of morphological elements, air cell depth) as well as of shell (weight, color, crushing strength, thickness, density, water conductivity), albumen (height, Haugh units, weight, pH) and yolk (weight, color, pH) were analyzed. The fatty acids profile of yolks was also evaluated as a freshness indicator. Packaging types available on the market, apart from its marketing and eggs protection function, can also influence the quality and stability of the product during storage. The use of plastic boxes can help to maintain higher eggs quality during the storage period, even after a significant extension of the storage time. Eggs stored in plastic boxes at room temperature had very similar results to those stored under refrigeration using conventional cardboard boxes. This effect is probably related to the lower permeability of plastic boxes in comparison to cardboard ones, but detailed research work in this direction is necessary to verify this relation.

Salmonella in eggs: From shopping to consumption-A review providing an evidence-based analysis of risk factors

Nontyphoidal salmonellae are among the most prevalent foodborne pathogens causing gastrointestinal infections worldwide. A high number of cases and outbreaks of salmonellosis are associated with the consumption of eggs and egg products, and several of these occur at the household level. The aim of the current study is to critically evaluate the current status of knowledge on Salmonella in eggs from a consumer's perspective, analyzing the hazard occurrence and the good practices that should be applied to reduce salmonellosis risk. Following a HACCP (Hazard Analysis and Critical Control Point) based approach, some steps along the food journey were identified as Critical Consumer Handling (CCH)-steps in which consumers, through their behavior or choice, can significantly reduce the level of Salmonella in eggs and egg products. From shopping/collecting to consumption, each of these steps is discussed in this review to provide an evidence-based overview of risk factors of human salmonellosis related to egg consumption. The main message to consumers is to choose Salmonella-free eggs (those that some official entity or producer guarantees that does not contain Salmonella), when available, especially for dishes that are not fully heat treated. Second, as guaranteed Salmonella-free eggs are only available in a few countries, refrigerated storage from the point of collection and proper cooking will significantly reduce the risk of salmonellosis. This will require a revision of the actual recommendations/regulations, as not all ensure that eggs are maintained at temperatures that prevent growth of Salmonella from collection until the time of purchasing.

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

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

How buyer-focused projective techniques can help to gain insights into consumer perceptions about different types of eggs

This study aimed to analyze the consumer perception (n = 840) about different types of eggs using Product Personality Profiling and Shopping List tasks. White egg, brown egg, organic egg, free-range egg, and eggs enriched with omega 3 and vitamins were evaluated. The consumers associated the white egg with unhealthy, sedentary, and overweight individuals in the Product Personality Profiling task and people that are not concerned with health in the Shopping List task. The brown egg was associated with a person who does physical activity and has a healthy diet in the Product Personality Profiling task. The omega 3 egg was associated with a person concerned with health in the Shopping List task, which does physical exercises and follows a healthy diet in the Product Personality Profiling task. The vitamin-enriched egg was associated with people with health disorders in the Shopping List task and following a vegetarian/vegan diet in the Product Personality Profiling task. The free-range egg was associated with a man with a rugged personality, a healthy diet, and animal welfare concern. Finally, the organic egg was associated with a person concerned with animal welfare and a vegetarian/vegan diet. Shopping list and Product Personality Profiling projective techniques proved to be useful tools for understanding consumer perceptions and beliefs about eggs, providing similar or complementary results. The Shopping List was more appropriate in eliciting egg buyers' profile, while the Product Personality Profile shows the "target buyer".

Consumers' Perspectives on Eggs from Insect-Fed Hens: A UK Focus Group Study

In recent years, there has been growing interest in insects as an alternative to soybean meal as laying hen feed due to nutrition, sustainability, and animal welfare benefits. Although some studies have investigated consumer acceptance and intentions towards insect-fed foodstuffs, no studies are available on eggs from insect-fed hens. This qualitative study aimed to explore consumers’ attitudes and perceptions towards eggs from insect-fed hens and factors influencing intentions to consume and purchase the product. Three focus group discussions were employed with a total of 19 individuals from the UK. Results showed that the environmental, animal welfare, and food waste benefits of feeding hens with insects positively influenced attitudes. Results also indicated price and disgust towards insects as feed were the main barriers, while enhanced welfare standards (e.g., free-range labelling) and information on benefits were main drivers. Therefore, the study suggests that educating and informing consumers about the benefits of feeding hens with insects may increase intentions to consume and purchase eggs from insect-fed hens. Given this emerging area of research, this study contributes to the limited literature on insect-fed foodstuffs and paves the way for further research on the topic.