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Issues related to food authenticity, traceability, and fraud have increased in recent decades as a consequence of the deliberate and intentional substitution, addition, tampering, or misrepresentation of food ingredients, where false or misleading statements are made about a product for economic gains. This study aimed to evaluate the ability of a portable NIR instrument to classify egg samples sourced from different provenances or production systems (e.g., cage and free-range) in Australia. Whole egg samples (n: 100) were purchased from local supermarkets where the label in each of the packages was used as identification of the layers' feeding system as per the Australian legislation and standards. The spectra of the albumin and yolk were collected using a portable NIR spectrophotometer (950–1600 nm). Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to analyze the NIR data. The results obtained in this study showed how the combination of chemometrics and NIR spectroscopy allowed for the classification of egg albumin and yolk samples according to the system of production (cage and free range). The proposed method is simple, fast, environmentally friendly and avoids laborious sample pre-treatment, and is expected to become an alternative to commonly used techniques for egg quality assessment. [ABSTRACT FROM AUTHOR]

There are only a few natural foods that contain nutritionally significant quantities of vitamin D. These include egg yolk, some fatty fish, and in much lower concentrations, meat. The published values of the vitamin D content of food are summarised here and their contribution to dietary vitamin D intake is discussed, with particular reference to Australia. Dietary vitamin D is unlikely to reach the level recommended by the US Institute of Medicine. It is therefore concluded that dietary vitamin D will only be a component of vitamin D supply, with UV exposure and/or oral supplements continuing to be the main sources of vitamin D to maintain adequate status. [ABSTRACT FROM AUTHOR]

A substantial increase in the usage of organophosphate esters (OPEs) as flame retardants and plasticizers in rubbers, textiles, upholstered furniture, lacquers, plastics, building materials and electronic equipment has resulted in their increasing concentrations in the environment over time. However, little is known about the concentrations and fate of OPEs and their metabolites (mOPEs) in biota, including chicken eggs. The aim of this study was to understand the spatial variation in the concentrations in chicken eggs and the partitioning between yolk and albumin. In total, 153 chicken eggs were purchased across Australia and analysed for 9 OPEs and 11 mOPE. Most of the compounds were found to be deposited in egg yolk, where diphenyl phosphate (DPHP, 3.8 ng/g wet weight, median) and tris(2-chloroisopropyl) phosphate (TCIPP, 1.8 ng/g wet weight, median) were predominant mOPE and OPE, respectively. Moreover, no spatial differences in concentrations of OPEs and mOPEs in eggs purchased from different locations were found in this study. Although comparable levels of ∑OPEs were detected in egg yolk and albumin, much higher concentrations of ∑mOPEs were found in yolk than albumin. Meanwhile, a negative correlation (R2 = 0.964, p = 0.018) was found between the molecular mass of analytes and partitioning coefficient of C yolk / C yolk+albumin (defined as chemical concentration in egg yolk divided by the sum of chemical concentrations in both yolk and albumin). These results indicate that n-octanol/water partition coefficients (log K OW) may not be a crucial factor in the distribution of OPEs and mOPEs between egg yolk and albumin, which is important in understanding distribution of emerging organic contaminants in biota. Image 1 • Concentrations of OPEs and mOPEs in chicken eggs across Australia were measured. • No spatial differences in OPEs or mOPEs concentrations were found in collected egg. • Partitioning of OPEs/mOPEs between yolk and albumin was estimated for the first time. • Yolk-albumin partitioning coefficient was negatively correlated to molecular mass. • Metabolism of OPEs in liver may contribute to the accumulation of mOPEs in egg yolk. Egg yolk has higher concentrations of ∑mOPEs than albumin, and yolk to albumin partitioning coefficient is significantly negatively correlated to the molecular mass of OPEs. [ABSTRACT FROM AUTHOR]

1. Eggs laid by the various strains entered in the 25th New South Wales Random Sample Layer Test were analysed for cholesterol content when the hens were 30, 45 and 60 weeks of age. 2. The strains differed in cholesterol content per gram of yolk and per egg. However most of the variation in cholesterol content per egg was attributable to strain differences in egg weight and in the proportion of yolk per egg. 3. Since 1 g of yolk contains approximately 6.7 times more energy and requires approximately four times the deposition energy of 1 g of albumen, the relation between the proportion of yolk within an egg and efficiency of egg production from food was considered. 4. It is recommended that comparisons of egg-laying strains and investigations into the efficiency of egg production from food should include an estimate of the proportion of yolk in the eggs.