Modified atmosphere packaging of hen table eggs: effects on functional properties of albumen

The aim of this study was to compare technological properties (gel hardness, foam drainage, and meringue crispness) of albumen of nonpacked table eggs (control) with those of eggs packed in high-barrier plastic pouches with 3 modified atmosphere packaging (MAP) conditions (air, 100% N(2), and 100% CO(2)) during 28 d of storage at 25°C. The values of gel hardness for the control sample showed an increasing trend, demonstrating the highest values throughout the experiment duration compared with the other samples. This behavior was probably attributable to the pH increase detected only for this sample during storage (from 8.82 ± 0.06 for fresh egg to 9.96 ± 0.06 at the end of the experiment). Air and N(2) samples showed constant and similar hardness values during storage. The hardness of coagulated albumen showed a strict correlation with raw albumen pH (r(2) = 0.929; P < 0.001). Other than reducing albumen pH during storage, MAP with CO(2) caused the formation of a soft and puffy coagulum with very low hardness, reaching the lowest value of 1.26 ± 0.38 N after 4 d of storage, that slowly increased to 2.11 ± 0.49 N at the end of the experiment. Foam stability decreased during storage for all samples, but CO(2) eggs showed a significantly (P < 0.05) higher foam stability than fresh eggs until 15 d, reaching values similar to those of the other samples only at the end of the storage time. Packing eggs in CO(2) promoted an improvement of meringue crispness. The application of this atmosphere could ameliorate the quality characteristics of albumen-based food products. Commercially, CO(2) MAP could provide an albumen-based ingredient tailored to maximize the characteristics needed in the final product (e.g., fresh shell eggs special for meringue preparation) that could give an added value to the product.