Salmonella Enteritidis is a pathogen related to many foodborne outbreaks involving eggs and egg products. Regulations about whether eggs should be pasteurized are very different and inconsistent worldwide. In the United States, eggs are not required to be pasteurized. Hence, less than 3% of the eggs in the country are pasteurized. The standard pasteurization method (57°C, 57.5 min) uses a long thermal process that increases the cost of the product and affects its quality. Foodborne outbreaks can be reduced if eggs are properly pasteurized to inactivate Salmonella spp. However, the technology to pasteurize eggs needs to offer a faster and more reliable method that can be scaled up to industry settings at a low cost and without affecting product quality. Several novel technologies have been tested for eggshell disinfection and egg pasteurization. Some thermal technologies have been evaluated for the pasteurization of eggs. Microwave has limited penetration depth and is a technical challenge for egg pasteurization. However, radio frequency can penetrate eggshells effectively to inactivate Salmonella , considerably reduce processing time, and maintain the quality of the product. Nonthermal technologies such as ultraviolet, pulsed light, cold plasma, ozone, pressure carbon dioxide, electrolyzed water, and natural antimicrobials have been explored for surface cleaning of the intact egg as alternatives without affecting the internal quality. This review presents some of these novel technologies and the current challenges. It discusses the possible combination of factors to achieve the egg's internal pasteurization and the eggshell's disinfection without affecting the quality at a low cost for the consumer.

Radio frequency (RF) is a novel technology with several food processing and preservation applications. It is based on the volumetric heating generated from the product’s dielectric properties. The dielectric properties of each material are unique and a function of several factors (i.e., temperature, moisture content). This review presents a list of dielectric properties of several foods and describes the use of RF as an innovative technology for the food industry. This paper includes several examples of pasteurization, fungi inactivation, and disinfestation in selected food products. The aim of this review is to present the potential applications of RF in pasteurization and disinfestation and research needs that should be addressed. RF has been successfully applied in the inactivation of pathogens such as Salmonella spp., Listeria monocytogenes, and Escherichia coli in low- and high-moisture food. The disinfestation of crops is possible using RF because of selective heating. This process inactivates the insects first because of the different dielectric properties between the pests and the food. The products’ final quality can be considerably better than conventional thermal processes. The processing time is reduced compared to traditional heating, and thermal damage to the food is minimized. The main drawback of the technology is the lack of uniform heating, mainly when the product is surrounded by a packaging material with different dielectric properties from the food.

Salmonella enterica serovar Enteritidis is the main pathogen of concern in eggs and egg products, although other serotypes have been reported worldwide. Egg processing guidelines and regulations vary widely from country to country; some are ambiguous, incomplete, or obsolete. However, foodborne outbreaks linked to Salmonella spp. and eggs continue to be reported worldwide and are constantly increasing, with many illnesses, deaths, and significant economic impact. This review aims to conduct a comprehensive investigation in egg processing regulations and Salmonella foodborne outbreaks in several countries of six continents in the last 50 years. The manuscript presents and contrasts the lack of surveillance programs, regulations, adequate testing, and traceability in some countries but also the creation of new regulations to reduce the incidence of Salmonella in eggs. One of the newest trends in the egg industry is related to farmers markets and backyard egg producers, which might represent a food safety gap in the production chain if these are not regulated. The review also discusses some interventions and approaches to control the growth and presence of Salmonella in fresh eggs, such as refrigeration. Though regulations in many countries do not require eggs to be under refrigeration and some other countries do not have enough access to them, jeopardizing the food safety of the product.

In the last two decades, much research has been carried out using ultrasound as an alternative for pasteurization. Cavitation, the main effect of ultrasound, can disrupt and perforate cell membranes, generate free radicals, and produce sonoluminescence. Ultrasound in combination with additional hurdles such as temperature, pressure, or antimicrobials can achieve a 5-log reduction. Pathogens, spoilage microorganisms, yeast, and molds have been successfully inactivated by this novel technology. Currently, ultrasound is investigated as an option to reduce the content of aflatoxins during pasteurization. Ultrasound can inactivate those enzymes related to the stability of pasteurized food products, extending the shelf-life of the products. New uses of sonication are surging; for example, ultrasound has been studied as an option for pasteurizing plant-based foods. An important area of research is ultrasound’s effect on food’s bioactive compounds. Results exhibit an increase in the concentration of phenolics, carotenoids, anthocyanins, and other nutrients after the use of ultrasound because of an extractive effect. Finally, an area of concern in the early ages of ultrasound has been studied, food quality. In most cases, sonicated products have similar quality parameters to raw products. Lastly, there are some areas of opportunity in ultrasound’s future, such as the equipment improvement, regulation, and toxicology of sonicated products.

Salmonella spp. represent a food safety risk in the production chain because of their potential for biofilm development. This study examined the biofilm formation of eight Salmonella serotypes from diverse foodborne outbreaks on three food-contact surfaces, stainless steel, silicone, and nylon, at 10 °C and 37 °C. The effect of temperature was observed in slower biofilm formation at 10 °C with about 5-log (cfu/cm²) after 24 h, contrasting with 7-log (cfu/cm²) at 37 °C. The material also influenced biofilm formation, with the strongest biofilms on stainless steel at 10 °C and silicone at 37 °C. The serotypes producing the strongest biofilms were S. Enteritidis, S. Saint Paul, and S. Montevideo. The weakest serotypes were S. Senftenberg, S. Anatum, and the avirulent S. Typhimurium. The production of extra-polymeric substances was evident with S. Enteritidis. The biofilm index showed the highest value for low temperature, nylon, and silicone, and for S. Montevideo, S. Enteritidis, and S. Saint Paul. The whole-genome sequencing of each serovar suggested that single nucleotide polymorphisms in the curli (csg) genes may have contributed to the strong biofilm-forming ability of S. Montevideo and S. Saint Paul and the weaker ability of S. Senftenberg. These results can help with the correct development of sanitizing interventions based on the Salmonella strain of concern.

Salmonella spp. can be present in pasteurized liquid egg products because of its heat resistance or post-processing contamination, thereby representing a food safety risk. The effect of 1000 IU nisin/ml plus 20 mM disodium ethylenediaminetetraacetic acid (EDTA), two refrigerated temperatures (7 °C and 10 °C), and two inoculation levels (10³ and 10⁵ cfu/ml) were studied in the growth of S. Typhimurium in pasteurized liquid whole egg (LWE). Two mathematical models were used to fit the microbial curves. Physicochemical characteristics of LWE, such as pH and color, were assessed for 31 days at the two storage temperatures, and no significant changes (p < 0.05) were observed for most of the samples. Results showed the significant impact of temperature on microbial growth. Samples kept at 7 °C showed the decay of microbial cells during storage; meanwhile, the effect at 10 °C was shown as fast growth. The combination of nisin plus EDTA and 7 °C accelerated the decay of microbial cells during the storage showing a synergistic effect. The Weibull model described the decline of cells during the shelf-life. Meanwhile, the logistic model fitted the growth of Salmonella in LWE at 10 °C. Adding these additives to LWE, combined with the correct temperature during pasteurization and adequate conditions during the cold chain, can minimize the food safety risk related to Salmonella.