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In order to investigate the effect of conventional packaging forms on the freshness of market shell eggs, this research investigated shell egg freshness of Roman pink in paper-based packaging without overlapped eggs arrangement, paper-based packaging with overlapped eggs arrangement, foam-based cushioning packaging, carton-based packaging, plastic-based packaging 5 groups. The shell eggs were stored at 25 ℃ for 30 d, and evaluated weight loss, air space diameter and height, yolk index, Haugh unit, thick-to-thin albumen ratio and albumen pH at 0, 10, 20, 30 d. The results showed that in shell eggs treated with paper-based packaging with overlapped eggs arrangement had significantly (P

Shell egg freshness is the key factor of evaluating egg quality. This review summarizes evaluation methods, influence factors of shell egg freshness, methods of retarding shell egg freshness deteriorations and future research directions of shell egg freshness. The results shows that egg freshness can be possibly evaluated by combination of destructive testing technology and non-destructive testing technology in an objective, dynamic and on-line manner. Hen age, diet, storage, transportation and environmental conditions can make a great influence on shell egg freshness. The characteristics of shell egg freshness can be possibly well maintained by adopting young hen, balanced nutrition diets, low temperature storage and avoiding mechanical damages during transportation and storage. Sterilization, packaging and coating methods can probably retard shell egg freshness deteriorations. Partially/totally adopting green, high efficient and energy-saving non-conventional food sterilization methods, and active, biodegradable and intelligent packaging/coating methods can possibly avoid microbial spoilage and retard egg freshness deteriorations during egg preservation. More researches of non-destructive testing technologies, diet formulations, simulating actual production, storage, transportation and sales, as well as optimization of non-conventional food sterilization-packaging and coating technologies need to be further explored, thus achieving quality improvement and industry promotion of shell eggs.

ABSTRACT: 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.

In the United States, all shell eggs processed under the USDA Agricultural Marketing Service voluntary grading standards must receive a shell sanitizing rinse of 100–200 ppm chlorine or its equivalent after leaving the washing process. A study was conducted to determine the concentration of peroxyacetic acid (PAA) which would be equivalent to 100–200 ppm chlorine (Cl) in reducing target organisms under the required washing conditions for shell eggs. Three isolates of Salmonella spp. (Enteritidis, Braenderup, and Typhimurium), as well as Enterobacter cloacae were used as inocula. Sanitizing treatments were negative control; deionized water; 100 and 200 ppm Cl; and 50–500 ppm PAA (7 concentrations). Considering all isolates tested, 100 and 200 ppm chlorine had 2.6 and 2.3 log cfu/mL cultural organisms remaining on shell surface; 50 and 100 ppm peracetic acid had 1.9 and 1.0 log cfu/mL cultural organisms remaining, respectively, compared with untreated control average of 3.8 log cfu/mL (P 250 ppm did not produce significant reductions in microbial populations as PAA concentration increased. Culturing for the prevalence of viable and injured organisms, 400–500 ppm PAA resulted in fewer eggs (P

Egg is a regularly consumed food item. Currently, chlorinated water washing is the most common practice used to disinfect eggs, but this process has a negative environmental impact. A new physical technique, plasma-activated water (PAW), has been demonstrated to possess effective antibacterial activities without long-term chemical residue. In this study, air PAW was used to inactivate Salmonella enterica serovar Enteritidis on shell eggs. Different combinations of activation parameters, including water sources (reverse osmotic (RO) water, tap water), power (40 W, 50 W, 60 W) and activation time (10 min, 20 min, 30 min), were evaluated. The oxidation−reduction potential (ORP) and pH values of each combination were measured, and their antibacterial activity was tested in a bacterial suspension. Higher antibacterial activities, higher ORP values, and lower pH values were obtained with higher power, longer activation time, and lower water hardness. The antibacterial activities of PAW decreased rapidly by increasing the storage time both at room and refrigeration temperatures. Afterwards, RO water was pre-activated for 20 min at 60 W, and then the eggs inoculated with S. enteritidis were placed into PAW for 30 s, 60 s, 90 s, or 120 s with a plasma on-site treatment in the water. More than a 4 log reduction was obtained with 60-s and 120-s treatments. The results showed that the freshness indexes of the eggs treated with PAW were similar to those of the untreated controls and better than those of the eggs treated with commercial processes. In addition, observation under a scanning electron microscope also showed less surface damage of the cuticle on the PAW-treated eggs than on the commercially treated eggs. The results of this study indicate that PAW could be an effective antibacterial agent with less damage to the freshness of shell eggs than commercial methods.