Searching the activity of chitosan based coatings produced with different kinds of organic acids to improve the shelflife and puncture strength of shell eggs

Despite eggs having a natural package-shell, they are perishable and could losequality. Chitosan containing organic acids [acetic-(Ch-AA), lactic-(Ch-LA), andpropionic (Ch-PA)]) were applied to shell eggs to evaluate on eggs interior qualityproperties (weight loss, Haugh unit, yolk index, pH, color: L, a, b), mineral amounts,puncture strength and also consumer preferences).All chitosan coated eggs showed greater interior quality than uncoated. Thelower weight loss (3.45 % for Ch-PA, 3.53 % for Ch-LA for) was observed in thecoated eggs than control. Chitosan coated Ch-PA and Ch-LA maintained a higherHaugh units and yolk index than uncoated. Uncoated changed from grade `A? to `B?after 1 week of storage. Ch-LA and Ch-PA acid maintained eggs in grade `A? during4 weeks. Chitosan coating maintained the mineral amounts (especially calcium, ironand magnesium) in yolks after 4 weeks storage.The albumen pH of the uncoated eggs was significantly higher than coated andincreased during storage. Uncoated had significantly lower albumen viscosity thanthe coated. Viscosity of albumen of eggs Ch-LA was significantly higher than Ch-AA.All chitosan coated eggshells showed significantly higher puncture strengththan those of uncoated eggs. Coated shell egg with Ch-LA also exhibitedsignificantly higher puncture strength. Ch-LA effectively maintain in preservingalbumen quality and puncture strength. Shell and yolk lightness (L*), (a), (b),chrome and hue values of coated eggs was similar of uncoated. There weresignificant differences in color (L) appearance in albumen among coated and fromuncoated. Based on sensory evaluation, consumers could not differentiate the coatedfrom uncoated eggs.Albumen quality (pH, viscosity and color) measurements are effectively usedto measure of freshness as interior quality of eggs.Keywords: eggs, shelflife, puncture strength, chitosan, coating, ICP, haughunit, yolk index, viscosity, consumer prefence.