ABSTRACT

In Nigeria and other developing countries, egg is produced all year round and it is a highly perishable product that if not given proper care between the time it is laid, time it is sold and the time it is consumed may deteriorate. The effects of pretreatment methods on some quality indices of stored shell-eggs was studied. Day old deep litter eggs were given the following treatments; hot oil (HOL), cold oil (COL), brine solution (BSN)), brine with antibiotics (BAS), pasteurization (PAU), while un(pre)treated shell-eggs (RTM) served as control. All eggs were stored at room temperature. The stored eggs were analyzed for their; physical, chemical, functional, amino acid, microbial and sensory properties. The results obtained indicated a significant decrease in egg weight among stored eggs (51.0-28.50g). Among the treated samples HOL recorded least decline in egg weight (51.0-50g), COL had highest haugh unit (78.03) at the end of storage. The yolk and albumen pH increased significantly (p < 0.05) from 6.04-7.43 and 8.51-9.21, respectivelyin RTM. COL and HOL retained AA grade all through storage period with RTM and PAU declined to B grade at the end of storage. RTM had lowest moisture content (56.84%), protein (10. 77%), while fat content increased in COL (11.26%) and HOL (11.17%) at end of storage. Result revealed there was a rapid decline in foaming capacity (100.15-50.73%), foaming stability (100.06-51.85%), emulsification capacity (42.20-28.51%), least gelation capacity (4-0) for the RTM at end of storage. COL recorded less decline in these functional properties. Coliform and fungi were not present in samples. The total bacteria count of the shell-eggs were <10⁵ cfu/ml while the RTM recorded moderate growth of total bacteria count 2.10 ×10⁵ at end storage.Cold oil treated eggs (COL) was the most accepted (5.50), followed by hot oil treated eggs (HOL) (4.75). However, the eggs stored under room temperature (control, 1.70) was the least preferred All essential amino acids were present in the shell eggs both at the beginning and at end of storage. PAU recorded highest decrease in total amino acid content (63.61-28.06%). Isoleucine was the most abundant amino acid in all samples while proline was the least. There was an increase in the total amino acid content of COL (19.49-43.98%). COL treatment offered best protective effect against decline of most of the studied quality indicators, next was HOL, and followed by BAS, the least was PAU.