Article

Temperature Sequence of Eggs from Oviposition Through Distribution: Production--Part 1

Department of Poultry Science, The Pennsylvania State University, University Park 16802, USA.
Poultry Science (Impact Factor: 1.67). 06/2008; 87(6):1182-6. DOI: 10.3382/ps.2007-00242
Source: PubMed

ABSTRACT

During Egg Safety Action Plan hearings in Washington, DC, many questions were raised concerning the egg temperature (T) used
in the risk assessment model. Therefore, a national study was initiated to determine the T of eggs from oviposition through
distribution. In part 1; researchers gathered data on internal and surface egg T from commercial egg production facilities.
An infrared thermometer was used to rapidly measure surface T, and internal T was determined by probing individual eggs. The
main effects were geographic region (state) and season evaluated in a factorial design. Egg T data were recorded in the production
facilities in standardized comparisons. Regression analysis (P < 0.0001) showed that the R2 (0.952) between infrared egg surface T and internal T was very high, and validated further use of the infrared thermometer.
Hen house egg surface and internal T were significantly influenced by state, season, and the state × season interaction. Mean
hen house egg surface T was 27.3 and 23.8°C for summer and winter, respectively, with 29.2 and 26.2°C for egg internal T (P < 0.0001). Hen house eggs from California had the lowest surface and internal T in winter among all the states (P < 0.0001), whereas the highest egg surface T were recorded during summer in North Carolina, Georgia, and Texas, and the highest
internal T were recorded from Texas and Georgia. Cooling of warm eggs following oviposition was significantly influenced by
season, state, and their interaction. Egg internal T when 3/4 cool was higher in summer vs. winter and higher in North Carolina
and Pennsylvania compared with Iowa. The time required to 3/4 cool eggs was greater in winter than summer and greater in Iowa
than in other states. These findings showed seasonal and state impacts on ambient T in the hen house that ultimately influenced
egg surface and internal T. More important, they showed opportunities to influence cooling rate to improve internal and microbial
egg quality.

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    • "Researchers from universities in California, Connecticut , Iowa, Illinois, North Carolina, Pennsylvania, and Texas and the USDA-Agricultural Research Service in Georgia gathered data on egg internal and surface temperatures , along with ambient temperatures, during their transport and distribution to warehouses and retail outlets from commercial processing plants (Koelkebeck et al., 2008; Patterson et al., 2008). This information was recorded over the course of 2 seasons. "
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    ABSTRACT: The Egg Safety Action Plan released in 1999 raised many questions concerning egg temperature used in the risk assessment model. Therefore, a national study by researchers in California, Connecticut, Georgia, Iowa, Illinois, North Carolina, Pennsylvania, and Texas was initiated to determine the internal and external temperature sequence of eggs from oviposition through distribution. Researchers gathered data from commercial egg production, processing, and distribution facilities. The experimental design was a mixed model with random effects for season and a fixed effect for duration of the transport period (long or short haul). It was determined that processors used refrigerated transport trucks (REFER) as short-term storage (STS) in both the winter and summer. Therefore, this summary of data obtained from REFER also examines the impact of their use as STS. Egg temperature data were recorded for specific loads of eggs during transport to point of resale or distribution to retailers. To standardize data comparisons between loads, they were segregated between long and short hauls. The summer egg temperatures were higher in the STS and during delivery. Egg temperature was not significantly reduced during the STS phase. Egg temperature decreases were less (P < 0.0001) during short delivery hauls 0.6 degrees C than during long hauls 7.8 degrees C. There was a significant season x delivery interaction (P < 0.05) for the change in the temperature differences between the egg and ambient temperature indicated as the cooling potential. This indicated that the ambient temperature during long winter deliveries had the potential to increase egg temperature. The REFER used as STS did not appreciably reduce internal egg temperature. These data suggest that the season of year affects the temperature of eggs during transport. Eggs are appreciably cooled on the truck, during the delivery phase, which was contrary to the original supposition that egg temperatures would remain static during refrigerated transport. These data indicate that refrigerated transport should be a component in future assessments of egg safety.
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    ABSTRACT: The Egg Safety Action Plan released in 1999 raised questions concerning egg temperature used in the risk assessment model. Therefore, a national study was initiated to determine the internal and external temperature sequence of eggs from oviposition through distribution. Researchers gathered data from commercial egg production, shell egg processing, and distribution facilities. The experimental design was a mixed model with 2 random effects for season and geographic region and a fixed effect for operation type (inline or offline). For this report, internal and external egg temperature data were recorded at specific points during shell egg processing in the winter and summer months. In addition, internal egg temperatures were recorded in pre- and postshell egg processing cooler areas. There was a significant season x geographic region interaction (P < 0.05) for both surface and internal temperatures. Egg temperatures were lower in the winter vs. summer, but eggs gained in temperature from the accumulator to the postshell egg processing cooler. During shell egg processing, summer egg surface and internal temperatures were greater (P < 0.05) than during the winter. When examining the effect of shell egg processing time and conditions, it was found that 2.4 and 3.8 degrees C were added to egg surface temperatures, and 3.3 and 6.0 degrees C were added to internal temperatures in the summer and winter, respectively. Internal egg temperatures were higher (P < 0.05) in the preshell egg processing cooler area during the summer vs. winter, and internal egg temperatures were higher (P < 0.05) in the summer when eggs were (3/4) cool (temperature change required to meet USDA-Agricultural Marketing Service storage regulation of 7.2 degrees C) in the postshell egg processing area. However, the cooling rate was not different (P > 0.05) for eggs in the postshell egg processing cooler area in the summer vs. winter. Therefore, these data suggest that season of year and geographic location can affect the temperature of eggs during shell egg processing and should be a component in future assessments of egg safety.
    Preview · Article · Jun 2008 · Poultry Science
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