Plasticizer types and whey protein coatings on internal quality and shelf life of eggs stored for 42 days

Abstract

Effects of plasticizer types and whey protein concentrate (WPC) as coatings were evaluated on internal quality and shelf life of eggs stored for 42 days. Eggs were coated with WPC at 8 % solution combined with the plasticizers glycerol (GLY), sorbitol (SOR), and propylene glycol (PRO). The eggs were stored at 20 °C. Weight loss, Haugh Unit (HU), albumen and yolk pH, and yolk index (YI) were evaluated weekly from day 0 to 42 days. After, electron microscopy of the eggshell structure was performed. The data was submitted to the analysis of variance and the effects of treatment, storage time, and the interaction between these factors were evaluated. There was significant interaction between factors (treatment and periods) for weight loss (p < 0.0001), HU (p < 0.0001), albumen (p < 0.0001), and yolk pH (p < 0.0001), and YI (p < 0.0001). After 42 days, uncoated eggs showed greater weight loss (5.4 %), compared to WPC+GLY, (3.8 %), WPC+SOR (3.3 %) and WPC+PRO (3.9 %). Similar results were verified for HU at 42 days of storage. Uncoated eggs showed HU of 58.46 (B), while coated eggs showed higher values: WPC+GLY -66.58 (A), WPC+SOR -68.79 (A), and WPC + PRO -71.53 (A). The plasticizers GLY, SOR and PRO, associated with WPC, demonstrated effectiveness in maintaining the quality of eggs throughout the 42 days of storage. However, WPC+SOR showed superiority in preserving quality integrity of eggs. This result can be related to the chemical structure of SOR, making the combination more efficient for storage.

The Impact of Package Type and Temperature on the Changes in Quality and Fatty Acids Profile of Table Eggs during Their Storage

“…Despite the positive effect of refrigeration methods on inhibiting negative changes in the quality of table eggs confirmed in studies [7,8], it is necessary to search for alternatives in this regard. So far, two main methods have been developed: coating egg shells with substances that limit water evaporation through shell pores [9][10][11][12] or using atmospheric modification [13]. These methods, although effective, are not currently of applicable importance.…”

Chitosan coatings and chitosan nanocomposite to enhance the storage stability of fresh eggs during storage

“…These results were similar to those of Kim et al (2007), Xu et al (2017), Suresh et al (2015), and Gabriela da Silva Pires et al (2021) which are effective in maintaining the pH of the albumen due to the barrier properties of coated samples were improved. Pires et al (2021) reported that the albumen pH gradually increased the initial average albumen pH of the eggs and was measured as 8.03, and this value increased to 9.51 after 6 weeks in the control eggs. Pires et al (2019) revealed that the use of coating with rice protein and propolis (10%) was able to extend the shelf‐life of fresh eggs based on albumen pH.…”

“…Gabriela da Silva Pires et al (2021) tested the rice protein concentrate, green propolis, and also combination of that in fresh eggs coating and verified that weight loss gradually increased during F I G U R E 3 Effect of chitosan and montmorillonite combinations on the rheological behavior of egg albumen at week 4 the storage, and control had the highest weight loss (5.41%) after 6 weeks of storage and coatings of rice protein (4.25%) or green propolis (4.08%), and rice protein and green protein (4.14%) solutions effectively reduced the weight loss. (Ezazi et al, 2021) reported that the minimum value of weight loss (0.73) for the coated eggs with chitosan and propolis coating was achieved at a moderate amount of propolis (35% w/v) and chitosan (1.5% w/v).…”

“…Ezazi et al (2021) revealed that the maximum value of HU (95.71) for the coated eggs with chitosan and propolis composite was obtained at a moderate amount of propolis (35% w/v) and a high amount of chitosan (3% w/v). (Gabriela da Silva Pires et al, 2021) indicated the HU values that control eggs changed in quality from grade AA to A after 3 weeks, while the change to grade B occurred after 6 week. Eggs coated with green propolis maintained a grade AA for up to 6 week.…”

“…The main changes that occur during storage is the increase in initial albumen pH (7.5 to 9.0) due to the loss of CO 2 from the breakdown of carbonic acid in the white, through the pores on the shell (Yuceer & Caner, 2014). The bio-coatings are effective in delaying this process by acting as a physical barrier, which reduces mass transfer (Gabriela da Silva Pires et al, 2021). Albumen thinning is the key factor that leads to changes in physicochemical properties of albumen proteins and results in an increasement in pH (to 9.5) (Omana et al, 2011).…”