二氧化碳浓度对鸡蛋呼吸强度及品质的影响

为了明确贮藏环境中二氧化碳（CO₂）浓度对鸡蛋品质的影响，将鸡蛋贮藏在CO₂浓度分别为0.03%（空气）、5%、10%和20%的贮藏箱内（分别记为A组、B组、C组和D组），探究CO₂对鸡蛋呼吸强度与新鲜度的影响，分析鸡蛋品质各指标值与呼吸强度之间的灰色关联度，为鸡蛋的贮藏、运输与保鲜提供理论支持。结果发现，B组、C组和D组鸡蛋呼吸被抑制，呼吸强度较弱，A组呼吸强度随贮藏时间延长而由强逐渐变弱；哈夫单位和蛋黄指数下降速率为A组 > B组 > D组 > C组，B组、C组和D组保质期均长于A组；贮藏过程中，A组pH值高于另外3组；A组在第5天后出现菌落，另外3组均在15天后出现菌落，A组贮藏45天的菌落总数约为另外3组的60倍。研究表明，鸡蛋在CO₂浓度为5%、10%、15%的贮藏环境中，呼吸强度被抑制，有抑菌保鲜的效果；通过灰色关联度分析发现，哈夫单位、蛋黄指数和pH值与呼吸强度的关联度较强，菌落数对呼吸强度影响较小；对比各种贮藏效果发现，CO₂浓度为10%与20%的贮藏组保鲜抑菌效果相近，均优于CO₂浓度为5%与0.03%的贮藏组，结合经济适用角度，最适宜鸡蛋贮藏保鲜的CO₂浓度为10%。

Egg preservation is of importance factor in the process of storage and transportation. To explore the effect of carbon dioxide on the storage quality and extend the shelf-life of eggs, fresh eggs, as the research subject in the study, were stored in the storage boxes with CO₂ at concentration of 0.03% (Air concentration), 5%, 10% and 20% (Divided into Group A, Group B, Group C and Group D, respectively). Furthermore, the study had an investigation into the impacts of CO₂ on the respiration intensity and freshness of eggs as well as the Grey Relational Analysis between index values and respiration intensity, which would provide theoretical support for egg storage, transportation and preservation. Under the general environment (25℃ and 65% humidity), the respiration of eggs in Group B, C and D were inhibited and the respiration intensity were weak, while the respiration intensity of Group A gradually decreased from strong to weak over time. The pH value of Group A was higher than the other three groups. The colonies formed in 5 days in Group A and in 15 days in the other three groups. Colonies count in Group A was about 60 times of that of the other three groups after storage for 45 days. In comparison with Group A, the rates of decrease of the egg Haugh units and egg yolk index in Group B, C and D were gentler, and the shelf-life of Group A was longer than that of Group B, C and D. In a word, the CO₂ at concentration of over 5% could effectively inhibit the respiration of eggs so as to achieve bacteriostat and preservation, and the most suitable CO₂ concentration was 10% among the four groups. There was a strong correlation between the respiration intensity and Haugh unit, yolk index as well as pH value, and the colonies count had the least effect on the respiration intensity.