Effect of Various Packaging Forms on the Freshness of Market Shell Eggs

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<0.05) higher values of weight loss (2.33%~7.35%), air space diameter (2.46~3.17 cm) and albumin pH (9.24~9.28), while obtained significantly (P<0.05) lower values of thick-to-thin albumen ratio (0.08~0.39) and yolk index (0.27~0.41). The Haugh unit decreased obviously (P<0.05) in shell eggs treated with carton and plastic-based packaging. Lower values of air space height were obtained in the shell eggs treated with foam-based cushioning packaging and paper-based packaging without overlapped eggs arrangement. Lower weight loss (0.62%~5.46%), air space diameter (2.02~2.62 cm), albumin pH (9.05~9.26) and higher yolk index values (0.27~0.48) were obtained in shell eggs treated with foam-based cushioning packaging. Furthermore, principal component analysis (PCA) could distinguish shell eggs treated with plastic-based packaging, foam-based cushioning packaging and other 3 packaging forms, and the contribution of freshness parameters was quite different between them. The results of this study indicated that the eggs treated with foam-based cushioning packaging could retard freshness deteriorations of shell eggs during storage, applying in shell egg storage and sale chain at the same environmental condition.