Influences of Egg Washing and Storage Temperature on Quality and Shelf Life of Duck Eggs During Storage

ABSTRACT Studies on how washing and storage influence duck egg quality are scarce compared with those on chicken egg quality. The present study investigated the quality of washed and unwashed duck eggs stored at 7 ºC and 25 ºC for 8 weeks. Quality parameters, including Haugh unit (HU), yolk index, thick albumen ratio, albumen pH, and air cell size, indicated that egg quality deteriorated during prolonged storage, and cuticle staining confirmed that washing reduced cuticle coverage. Washed eggs stored at 7 ºC maintained high quality (grade B; HU: 54) according to the United States Department of Agriculture (USDA, 2000) after storage for 8 weeks, whereas unwashed eggs stored at 25 ºC exhibited a low but acceptable quality (grade B, but HU: 36) after 7 weeks. Strong correlations were observed between the quality parameters evaluated. In conclusion, duck eggs should be washed and then stored at 7 ºC to enhance microbial safety and maintain quality to achieve a shelf life of at least 8 weeks.摘要：相较于针对鸡蛋品质的相关研究，有关清洗与贮藏对鸭蛋品质影响的研究仍较为匮乏。本研究针对分别置于7℃与25℃环境下贮藏8周的清洗组与未清洗组鸭蛋的品质展开了探究。本次研究测定的品质指标包括哈氏单位（Haugh Unit, HU）、蛋黄指数、浓蛋白比例、蛋白pH值以及气室尺寸，结果显示鸭蛋品质随贮藏时长延长而发生劣变；通过角质层染色法证实，清洗操作会降低蛋壳角质层的覆盖率。根据美国农业部（United States Department of Agriculture, USDA，2000）的标准，贮藏8周后，7℃下存放的清洗组鸭蛋仍维持较高品质（B级；哈氏单位：54）；而25℃下贮藏的未清洗组鸭蛋在7周后虽品质偏低，但仍处于可接受范围（B级，哈氏单位：36）。各测定品质指标间均存在显著相关性。综上，为提升鸭蛋的微生物安全性并维持其品质以实现至少8周的货架期，建议对鸭蛋进行清洗后置于7℃环境下贮藏。