Albumen pH Research Articles

Microwave spectroscopy in a free-space arrangement for nondestructive quality assessment of chicken eggs: Comparing different measurement modes and feature selection approaches

A free-space dielectric arrangement with X-band coaxial-to-waveguide adapters was used to non-destructively assess shell egg quality. Scattering parameters in the microwave spectral range (8–12 GHz) were measured in reflectance and transmittance modes from eggs placed in three orientations. Partial least squares regression was applied to predict egg quality indices, including air cell height (ACH), yolk coefficient (YC), thick albumen height (TAH), Haugh unit (HU), and albumen pH. Prioritizing PR_S22 spectrum in horizontal 1 orientation, several feature selection methods were employed to identify the most effective frequencies. Artificial neural networks (ANNs) were then used to develop predictive models based on influential frequencies. The competitive adaptive reweighted sampling method consistently outperformed others, yielding robust ANN models with excellent residual predictive deviation values of 4.80, 4.00, 3.27, 3.03, and 3.72 for ACH, YC, TAH, HU, and albumen pH, respectively. This study demonstrates the effectiveness of free-space dielectric arrangements in predicting egg quality.

Impact of High-Dose Supplemental Paprika Extract Feeding on Egg Storage and Biochemical Parameters in Laying Hens.

This study aimed to evaluate the effects of paprika extract supplementation on egg storage and blood biochemical parameters in 63-week-old Rhode Island Red (RIR) and Silky Fowl (SF) hens. The hens were divided into three groups: a control group with a basal diet and two groups receiving the basal diet with paprika extract. The trial lasted 28 days, with egg quality (yolk color and albumen pH) assessed after storing eggs at 25 °C for 21 days. A total of 144 eggs were used in 42 treatments (two breeds, three diets, and seven storage periods) with three eggs examined each (four eggs were used on day 0 and five eggs on day 21). Additionally, the yolk carotenoid content, yolk color, and pH of eggs stored at 4 °C and 25 °C were compared. Results showed that yolk color fan score (YCFS) decreased with storage, and SF had a higher albumen pH than RIR, with both breeds exhibiting an increase in pH over time. HDL cholesterol (HDL-C) levels and the HDL-C to total cholesterol ratio were significantly influenced by breed, diet, and their interaction. The HDL-C level in SF was affected linearly and quadratically by diet, while no such trend was observed in RIR. The study concluded that paprika extract affects egg quality and blood lipid profiles differently in different breeds, highlighting breed-specific responses to dietary supplementation.

Radio frequency plus heat for in-shell egg pasteurization

Less than 3 % of the eggs in the United States are sold pasteurized because of the long thermal process (~ 60 min). However, this represents a food safety risk because of the possible presence of Salmonella spp. inside the egg. This research studied the inactivation of S. typhimurium in in-shell eggs using the novel technology radio frequency (RF) to enhance their food safety, evaluating quality, presence of sub-lethally injured cells (SICs), and cell recovery (7 °C). Eggs were inoculated inside with S. typhimurium (105 CFU/egg) and processed with RF (40.68 MHz, 35 W, 4.5 min) followed by hot water spray (H, 56.7 °C, 20 min). The studied quality attributes were yolk color, Haugh unit, yolk index, shell breakage strength, yolk and albumen pH, and albumen degradation. ANOVA one–way was used to find significant differences (α = 0.05). RF plus heat can pasteurize the eggs after 24.5 min (5-log reduction). No SICs were detected in any of the samples, and cells did not recover after five days of storage (Limit of detection <1 log CFU/g). Most quality attributes were like the control eggs. Albumen degradation showed a significant difference (p < 0.05) after processing. RF represents a potential option to ensure the safety of in-shell eggs, preserving their quality. Industry relevanceMost in-shell eggs are sold unpasteurized worldwide with the potential risk of Salmonella spp. The conventional pasteurization process is a lengthy intervention that adds cost to the product and can damage the quality of eggs. Radio frequency plus heat pasteurization offers an alternative to pasteurizing in-shell eggs with a volumetric heating process that inactivates Salmonella cells inside the eggs and has minor effects on the quality of eggs. This technology is a novel option for the egg industry, providing high-quality and reasonably priced safe eggs.

Effect of hot red pepper supplementation and different storage time on hens egg quality

Introduction. Eggs are a food source of protein that easily deteriorates during storage. Supplementation of hot red chilli pepper powder rich in bioactive compounds in diets for laying hens can improve egg quality and prevent egg deterioration during storage. Objective. To determine the effect of hot red pepper powder supplementation and different storage times on the physical egg quality of laying hens. Materials and methods. This study was conducted from January to March 2024 at the Research Barn of PT. Agromix Lestari Group, Kulon Progo, Yogyakarta, Indonesia. Eighty 56-week-old Novogen laying hens (1681 ± 64 g) were assigned into four dietary treatments (4 replications, 5 hens per replication): basal diet as control (P0); basal diet + 0.25 % hot red pepper powder (P1); basal diet + 0.5 % hot red pepper powder (P2); and basal diet + 0.75 % hot red pepperpowder (P3). At the end of week 6, one egg per replicate group was collected and analyzed for physical quality in three storage treatments: fresh condition (S0), one week storage (S1), and two weeks storage (S3). Egg quality data were analyzed with a factorial experimental design (4 x 3) using SPSS 26 software. Results. Supplementation of 0.5 % hot red pepper powder significantly increased egg weight. Hot red pepper addition and treatment duration significantly affected egg yolk colour. The hot red pepper treatment group showed significantly lower pH of albumen and yolk. Conclusions. The supplementation of hot red pepper powder in laying hens diets has been shown to improve the egg yolk color. The inclusion of 0.5 % in the ration was able to keep the pH of yolk and albumen low.

Internal quality of commercial eggs subjected to different shell treatments and storage times

Five hundred sixty eggs from commercial layers aged 74 weeks were subjected to sanitization and shell-covering procedures. The treatments consisted of two egg sanitization methods, sanitized (S) and not sanitized (NS), and two methods of shell covering, not covered (NC) and covered (C) with whey protein concentrate solution, arranged in a completely randomized design in a 2 × 2 factorial scheme (sanitization × shell coating), with five replications obtained from the average of four eggs evaluated in seven storage periods (1, 7, 14, 21, 28, 35, and 42 days). Albumen pH and yolk lipid oxidation using the TBARS test were evaluated. The averages for each period were submitted to analysis of variance, any differences observed were submitted to the Tukey test (5%), and regression analysis was performed between periods for each method. Using SDS-PAGE, the protein profile of albumen at 1 and 42 days was evaluated descriptively. Using methods S and NS, the pH and TBARS of eggs did not change on any of the days evaluated (P&gt;0.05). Methods C and NC had similar pH values (P&gt;0.05) only when using fresh eggs; however, the pH was higher when using eggs from Method NC (P&lt;0.0001) compared with Method C. For all techniques, the analysis of pH regression between periods revealed quadratic behavior. While regression analysis demonstrated an increasing linear behavior for all methods, the TBARS analysis results for C and NC on all evaluated days were comparable (P&gt;0.05). Whey protein concentrate does not affect the pH of sanitized eggs. The protein profile of the albumen and TBARS values of egg yolks stored at room temperature are unaffected by sanitation and whey protein concentrate covering, and TBARS values increase over storage days in all cases.

Effects of Supplementing Selenium-Enriched Cardamine violifolia to Laying Hens on Egg Quality and Yolk Antioxidant Capacity during Storage at 4 °C and 25 °C.

Oxidative stress occurs in the process of egg storage. Antioxidants as feed additives can enhance egg quality and extend the shelf life of eggs. Selenium-enriched Cardamine violifolia (SEC) has strongly antioxidant properties. The objective of this study was to assess the effects of dietary supplementation with SEC on egg quality and the yolk antioxidant capacity of eggs stored at 4 °C and 25 °C. Four hundred fifty 65-week-old, Roman hens that were similar in laying rate (90.79 ± 1.69%) and body weight (2.19 ± 0.23 kg) were divided into 5 groups. The birds were fed diets supplemented with 0 mg/kg selenium (Se) (CON), 0.3 mg/kg Se from sodium selenite (SS), 0.3 mg/kg Se from Se-enriched yeast (SEY), 0.3 mg/kg Se for selenium-enriched Cardamine violifolia (SEC) or 0.3 mg/kg Se from Se-enriched Cardamine violifolia and 0.3 mg/kg Se from Se-enriched yeast (SEC + SEY) for 8 weeks. The eggs were collected on the 8th week and were analyzed for egg quality and oxidative stability of yolk during storage at 4 °C or 25 °C for 0, 2, 4, or 6 weeks. Dietary SEC and SEC + SEY supplementation increased the Haugh unit (HU) and albumen foam stability in eggs stored at 4 °C and 25 °C (p < 0.05). SS and SEC supplementation increased the yolk index in eggs stored at 25 °C (p < 0.05). SEC or SEC + SEY slowed down an increase in albumen pH and gel firmness in eggs stored at 4 °C and 25 °C (p < 0.05). Moreover, SEC or SEC + SEY alleviated the increase in malonaldehyde (MDA), and the decrease in total antioxidant capacity (T-AOC) level and total superoxide dismutase (T-SOD) activity in yolks stored at 4 °C and 25 °C (p < 0.05). These results indicate that SEC mitigated egg quality loss and improved the antioxidant capacity of yolks during storage. SEC supplementation would be advantageous to extend the shelf life of eggs.

Effects of short heating periods during egg storage on quail embryonic development, incubation performance, chick quality, and chick performance up to 35 days

This study investigated the effects of pre-heating fertile Japanese quail eggs during storage on embryonic development, incubation performance, hatched chick quality, and chick performance up to 35 days of age. The experiment was laid out in a completely randomized design in a 3 × 2 + 1 factorial arrangement, totaling seven treatments. These treatments included three storage periods (3.5, 6.5, and 9.5 days) and two pre-heating periods (0 and 4 h at 37.5°C and 60% RH). Pre-heating was conducted on the third day of egg storage inside the incubator machine, with the control treatment involving the storage of fertile eggs for 12 h without pre-heating. Extended egg storage for more than six days led to an increase in the percentages of yolk and shell, elevated albumen pH, reduced albumen percentage, diminished hatchability rate, and an increased embryonic mortality rate. Pre-heating the eggs resulted in a reduction in the weight, length, and amount of residual yolk sac of the newly hatched chick. No significant effects of pre-heating fertile Japanese quail eggs during storage were observed on the studied variables. Therefore, the protocol involving a 4-h pre-heating at 37.5 ºC and 60% relative humidity during the storage period does not yield improvements in incubation rates or chick quality in Japanese quail. Further studies are warranted to determine the optimal protocol for pre-heating Japanese quail eggs.

Egg quality characteristics of sussex chickens reared under the housing conditions of Cukurova University farm

This work was conducted to evaluate the egg quality characteristic of Sussex multi-purpose chickens reared under the housing conditions of the Cukurova University Farm. A total of 81 Sussex chickens from the Poultry and Research Unit of Cukurova University were used in this study. The external and internal egg-quality paraemeters were determined using 30 eggs on both the 28th and 33rd weeks of egg production cycle. The egg quality parameters measured were the Haugh unit, breaking strength, yolk color, shell thickness, egg weight, shape index, shell weight, albumen index, yolk index, and albumen pH. The egg weight, albumen index, yolk index and Haught unit were 57.89±3.99g, 9.44±2.07, 43.22±3.57 and 84.85±8.87 respectively. The shape index, shell thickness, shell weight, shell breaking strength and albumen pH were %75.32±2.11, 0.338±27.84mm, 5.903±0.645g, 3.825±1.065 kg/cm2 and 7.84±0.18 respectively. The yolk color, L, a, b and E values were 55.85±7.02, 13.91±3.33, 47.18±7.90 and 74.99±5.96 respectively. It was concluded that the external and internal egg-quality parameters of Sussex chickens reared under the housing conditions of the Cukurova University Farm were between the normal range.

The Effect of Casein-Chitosan Edible Coating with Garlic Essential Oil Addition on pH, Haugh Unit and Egg Yolk Index Fresh Chicken Egg on Different Storage

Eggs are a source of animal protein needed by the body and contain complete essential amino acids. Chicken eggs are easily damaged or changed so the quality of the eggs decreases with the length of storage. This damage can be prevented by coating. Past studies concluded that edible coating can maintain the quality of chicken eggs. The purpose of this study was to determine the effect of coating chicken eggs using chitosan and casein edible coating with the addition of garlic essential oil. The materials used are fresh chicken eggs, edible coating solution and garlic essential oil. The method used in this study was a laboratory experiment with Completely Randomized Nested Design with 2 treatments and 3 replications. Edible coating with the addition of garlic essential oil is expected to improve egg quality with a long shelf life. The result showed that chicken eggs coated with chitosan casein edible coating with the addition of garlic essential oil 1% for storage time of 0 days, 7 days, 14 days, 21 days and 28 days gave a very significant effect (P&lt;0,01) on egg yolk pH, egg albumen pH, haugh unit and egg yolk index.

The effect of different layer genotypes raised in the Free-range system on egg quality storage at different temperatures

The aim of this study was to investigate the effect of stored eggs obtained from different layer genotypes raised in a Free-range system on egg quality at different storage temperatures. Lohmann Brown, Lohmann Sandy, and ATAK-S were used as layer genotypes in the study. The study was performed in a 3x2 factorial design with three genotypes and two storage temperatures. A total of 300 table eggs were used in the study. Egg quality analysis was carried out on 100 eggs from each genotype. Eggs were stored in refrigerator (4±2°C) and at room temperature (22±2°C) for 28 days. Egg quality was determined in 10 eggs from each group after 0, 7, 14, 21, and 28 days of storage, and the effects of temperature, genotype, and temperature x genotype interaction were determined. In the study, the effects of genotype and storage temperature on egg weight loss, Haugh unit, yolk index, and albumen pH were determined to be significant (P&amp;lt;0.05). However, the interaction effects of storage temperature x genotype were not statistically significant for any period of storage on egg quality characteristics such as Haugh unit and albumen pH. As a result, it was determined that eggs stored at refrigerator temperature during the research, depending on the storage conditions, preserved their quality characteristics better than those stored at room temperature. The study concluded that the eggs of the ATAK-S genotype had a lower shelf life compared to those of the Lohmann Sandy and Lohmann Brown genotypes.

Preservation of chicken egg quality using pectin derived from water hyacinth

This study investigates the potential of pectin derived from water hyacinth, an aquatic floating weed, as a coating material for chicken eggshells to preserve egg quality and extend shelf life. A total of 240 fresh chicken eggs were divided into four groups: 1) uncoated (control), 2) coated with a 2 % chitosan solution, 3) coated with a 1.5 % solution of pectin from water hyacinth, and 4) coated with a 2.5 % solution of pectin from water hyacinth. The eggs were stored at room temperature for 35 days before egg quality parameters, including weight loss, Haugh unit, yolk index, and albumen pH, were measured on a weekly basis. The results showed that eggs coated with water hyacinth pectin exhibited significantly lower weight loss and albumen pH (p < 0.05) compared to the uncoated eggs. Furthermore, the water hyacinth pectin coating effectively maintained the Haugh unit at Grade A levels for up to 28 days of storage. These findings suggest that the water hyacinth pectin coating acts as a protective barrier, limiting the transfer of water and carbon dioxide through the eggshell, thereby preserving egg quality and extending shelf life. In summary, water hyacinth pectin demonstrated promising potential as an environmentally friendly coating material, offering an alternative approach to maintaining egg quality and extending shelf life.

Effect of Enrichment of Laying Quail Diets with Organic Selenium on Performance and Fresh and Stored Egg Quality

Selenium, which is a good antioxidant, is an essential trace mineral and its organic forms are more available than inorganic forms. Dietary deficiency or excess of this trace mineral causes health problems in poultry, and therefore the amount of selenium in the diet is controversial. The current research was carried out to determine the effect of diets enriched with organic selenium on the performance, egg quality, and stored egg properties in laying quails. In the study, 120 laying quails were allocated to six treatment groups with 20 quails in each, with five subgroups. Quails were fed for 70 days with experimental diet containing 0.12 mg/kg selenium based on corn-soybean meal enriched with the addition of organic selenium (Sel-Plex) at 0.0, 0.2, 0.4, 0.6, 0.8, or 1.0 mg/kg. Body weight change decreased linearly with the addition of 0.6 mg/kg and further levels of organic selenium (P&lt;0.05). Feed intake quadratically increased with the supplementation of organic selenium up to 0.8 mg/kg, but it was minimum at 1.0 mg/kg (P&lt;0.05). The eggshell quality parameters were not affected by the administration of organic selenium to the diet (P&gt;0.05). Albumen pH linearly decreased with organic selenium supplementation up to the level of 0.60 mg/kg, but increased with the addition of higher levels of organic selenium (P&lt;0.05). With the addition of organic selenium to the diet, yolk L* and b* values quadratically and linearly decreased respectively, while a* value increased linearly (P&lt;0.01). Albumen pH value of stored eggs was linearly decreased by treatments (P&lt;0.01), but other parameters did not affect (P&gt;0.05). As a result, it was determined that laying quails can be fed with diets enriched with organic selenium up to 0.4 mg/kg and the eggs could maintain the freshness for a longer time in during storage.

Evaluation of the application effect of visual indicator coatings based on H2S for predicting the shelf-life of eggs

Eggs coated with visual indicator coatings were stored at 5, 15, 25, and 35 °C. The effects of storage time and temperature on changes in quality were studied using physicochemical indices. The results showed that the albumen pH and the diameter of the air space of coated eggs increased with storage time and temperature but the weight, Haugh unit, yolk index and L* value decreased. During the entire trial, the weight loss of coated eggs stored at 5 ℃ was less than 5% with the other quality indicators being better than those of coated eggs stored at higher temperatures. The hydrogen sulfide (H2S) produced by the breakdown of sulfur-containing proteins can be considered a reliable indicator for evaluating the freshness of coated eggs. A visual indicator coating based on H2S was prepared and used to predict the shelf-life of eggs. Subsequently, a shelf-life prediction model was developed using a kinetic model of changes in the L* value of the visual indicator coatings on the eggshell. The results showed that the prepared visual indicator coatings provided the expected L* response toward H2S. The L* value was highly correlated with various indices, indicating that the L* value could be used as a critical quality index to establish the shelf-life prediction model. Verification based on the L* value indicated that the relative errors between the predicted and experiment values were less than 10%. Overall, the visual indicator coatings can provide valuable information on egg quality to assure their freshness.

Evaluation of shelf life of egg treated with edible coating by means of NIR spectroscopy and laser induced diffuse reflectance imaging

A coating solution was developed by blending cassava starch at different levels (2%, 3% and 4% w/v) with gelatin and plasticizers to maintain the quality of eggs during 4 weeks of storage (25 ± 1 °C, 60–65% RH). This study suggests the rapid techniques of near-infrared (NIR) spectroscopy and laser-induced diffuse reflectance imaging for determining the internal quality of eggs. The scanning electron microscopy (SEM) micrographs showed that the coatings were effective in protecting eggshells. During storage, coated eggs had lower weight loss and albumen pH, higher Haugh unit and yolk index than control eggs (p < 0.05). These factors are the most common parameters in assessing egg quality. Among the coating formulas, the 4% starch coating had significantly higher effectiveness from the 3rd week of storage. The results indicated that the coating solution containing 4% starch could maintain the egg quality up to 28 days. Furthermore, the NIR spectra were used to develop prediction models for the investigated quality attributes using partial least squares regression (PLSR). Models were created using 3 preprocessing methods of standard normal variate (SNV), first derivative (lD) and second derivative (2D). The PLSR-SNV model achieved the best prediction for weight loss (R2 = 0.883, RPD = 2.920), Haugh unit (R2 = 0.756, RPD = 2.025), and yolk index (R2 = 0.807, RPD = 2.276). Laser scattering was successfully used to detect the egg quality change during storage by linear discriminant analysis (LDA) at wavelengths of 532 nm and 780 nm. The descriptive attributes extracted from intensity profiles showed significant effects of storage time, treatment and their interaction. This research highlighted the promising application of NIR and laser-induced diffuse reflectance imaging for inline control of egg quality at room temperature.

Influence of non-ventilating intervals during early incubation stage on egg hatching process.

The exchange of oxygen and carbon dioxide (CO2) in the incubator plays a key role in embryonic development and hatching. This study aimed to study the effect of non-ventilated (NV) intervals during the early stage of embryonic development on the hatching process. Hatching eggs (n = 7200) were equally divided into four treatment groups and incubated in four incubators. The first group was incubated in normal ventilated condition (V) during the setting phase of incubation. Ventilation holes of the three remaining incubators were closed for the first 3, 6, and 9 days and termed as NV groups (NV1, NV2, and NV3, respectively). A gradual increase in CO2 was allowed for NV groups, followed by opening the incubator holes to permit ventilation throughout the rest of the incubation periods. Obtained results demonstrated that CO2 concentration gradually increased up to 0.19% for the NV1 group, 0.41% for the NV2 group, and 0.90% for the NV3 group, while CO2 concentration remained at 0.08% during the first 9 days of incubation in the V group. Albumen pH was lowered for all NV groups. The highest hatchability percentage was recorded for NV3 followed by NV2 and NV1 groups. All NV groups represented earlier and narrower spread of hatch and higher hatched chick weight. Embryos and hatched chicks in the NV groups had higher hormonal levels of thyroxin and corticosterone. All non-ventilation periods had positive effects on narrowing the spread of hatch, increasing hatched chick weight and hatchability percentage compared to the normal V condition. Furthermore, the non-ventilation throughout the first 9 days of incubation yielded the best hatching results.

Comparative study of egg quality parameters of different breeds of peacock

ABSTRACT The current research work was conducted to compare the external and internal egg quality parameters of different breeds of peacock. For this purpose, 130 freshly laid eggs of 2 species and 11 breeds (n = 10 per breed) were obtained from captive breeding facilities. In Pavo muticus muticus, higher egg weight (106.57 ± 0.69), egg length (7.21 ± 0.01), egg width (5.31 ± 0.01), egg breadth (28.18 ± 0.01), and egg volume (100.84 ± 0.48) were recorded. However, higher egg shape index (80.16 ± 0.27) was noted in black shoulder, while higher egg surface area (263.8 ± 0.01) was found in Spalding purple. Significantly higher albumen diameter (11.02 ± 0.05), albumen weight (47.06 ± 0.24), albumen height (0.946 ± 0.02), albumen ratio (49.83 ± 0.13), yolk height (1.66 ± 0.01), yolk index (35.75 ± 0.13), and shell thickness (0.67 ± 0.00) were found in Pavo cristatus. Albumen pH (6.43 ± 0.01), yolk diameter (6.93 ± 0.04), yolk ratio (61.80 ± 0.87), and yolk weight (51.66 ± 0.34) were noted to be higher in Indian white. Higher shell weight (16.38 ± 0.42), shell ratio (17.004 ± 0.38), and Haugh unit (88.57 ± 0.84) were observed in Buford bronze pied. The study suggested that P.m. muticus and Pavo cristatus showed best external and internal egg quality traits as compared to other breeds. It further provided a reference and theoretical basis for artificial breeding, ecological protection, raising, and management of different breeds of peacocks.

Downregulation of extraembryonic tension controls body axis formation in avian embryos

Embryonic tissues undergoing shape change draw mechanical input from extraembryonic substrates. In avian eggs, the early blastoderm disk is under the tension of the vitelline membrane (VM). Here we report that the chicken VM characteristically downregulates tension and stiffness to facilitate stage-specific embryo morphogenesis. Experimental relaxation of the VM early in development impairs blastoderm expansion, while maintaining VM tension in later stages resists the convergence of the posterior body causing stalled elongation, failure of neural tube closure, and axis rupture. Biochemical and structural analysis shows that VM weakening is associated with the reduction of outer-layer glycoprotein fibers, which is caused by an increasing albumen pH due to CO2 release from the egg. Our results identify a previously unrecognized potential cause of body axis defects through mis-regulation of extraembryonic tissue tension.

Effect of Hen Genotype and Laying Time on Egg Quality and Albumen Lysozyme Content and Activity.

According to research, egg quality and lysozyme content are influenced by a number of factors, which are mostly known in the case of commercial hybrids, while in breeds included in genetic resources conservation programmes, new research results in this regard are emerging. The aim of the study was to determine the effect of egg laying time and genotype of selected Polish native breeds of hens on egg quality and lysozyme content and activity in the albumen. The study material consisted of eggs collected from four strains of laying hens included in the Polish conservation programme, i.e., Green-legged Partridge (Z-11), Yellow-legged Partridge (Ż-33), Rhode Island Red (R-11) and Leghorn (H-22). At week 56, 28 eggs were randomly collected at 7:00 and 13:00 h from each breed of hen and assessed for quality. Laying time influenced certain egg quality traits. Eggs laid by hens in the morning were characterised by 1.7 g lower total weight and albumen weight, 2.4 pores/cm2 higher number of shell pores, 0.15 higher albumen pH values and 0.17 lower yolk pH values compared to those laid in the morning. The time of laying did not affect the level and activity of lysozyme in the albumen. A significant negative correlation was found between eggshell traits and albumen height, and between Haugh unit and lysozyme content and activity in the albumen. The studied egg quality traits were more influenced by genotype than by the egg-laying time.

Effect of rapeseed oil and β‐cyclodextrin coatings on the quality of eggs in shell

SummaryThe objective of this research was to investigate and compare the effect of rapeseed oil, 0.5% β‐cyclodextrin (β‐CD) and rapeseed oil/0.5% β‐cyclodextrin coating on egg quality attributes during storage for 28 days at 25 °C. Egg quality attributes such as weight loss (WL), air cell depth and diameter, Haugh unit (HU), albumen pH, yolk index and colour, eggshell strength and morphology were monitored. Similar initial quality attributes of control, rapeseed oil, 0.5% β‐CD and rapeseed oil/0.5% β‐cyclodextrin‐coated eggs were obtained at day 0. Control (uncoated) and β‐CD‐coated eggs had the worst WL, air cell diameter, air cell depth, albumen pH and a* values after storage for 28 days at 25 °C, while the rapeseed oil/0.5% β‐cyclodextrin‐coated eggs had lower values of air cell diameter (18.20 mm), air cell depth (7.20 mm) and albumin pH (9.12), higher eggshell breaking strength (51.21 N) and a*(25.33). At day 7 and 21, the best quality attributes were obtained by rapeseed oil/0.5% β‐cyclodextrin‐coated eggs, being respectively: WL, yolk index and L*. Less obvious micro‐cracks on the eggshell surface were detected especially in rapeseed oil/0.5% β‐cyclodextrin‐coated eggs, which maintained slightly improved egg quality attributes during storage.

Potential of Full-Fat Silkworm-Based Diets for Laying Quails: Performance and Egg Physical Quality.

The present research was conducted to determine the optimal inclusion level of full-fat silkworm chrysalis meal (SWM) into laying quails' diets, focusing on performance traits and egg physical quality. A total of 240 31-day-old female Japanese quails were randomly assigned to four dietary groups (12 replicates/treatment; 5 quails/replicate); quails were initially fed a standard commercial diet for pullets until 63 days of age. When oviposition started, the experimental groups received the following diets: a conventional corn and soybean-based diet (control diet-C) and three other diets, including 4%, 8%, or 12% of full-fat SWM (SWM4, SWM8, SWM12, respectively). Experimental diets were provided until quails reached 119 days of age. Birds displayed satisfactory productive performance throughout the trial. SWM12 and SWM8 had higher (p < 0.001) egg production but also a higher feed conversion ratio compared to C. At the end of the trial, the eggs edible portion increased, and shell weight decreased with increasing the SWM dietary inclusion level (p < 0.001). At the same time, SWM12 displayed an increase in albumen pH (p < 0.05), even though in the normal range for quail egg. Overall, full-fat SWM (up to 12%) can be considered a promising feed ingredient for laying quails, although higher inclusion levels (>8%) require special attention because SWM also contains anti-nutritional factors.