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

Background: 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. Objective: 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. Methods: 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. Results: 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. Conclusion: 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.