engleski

Selenium and physical-chemical indicators of hen´s egg quality

Egg is a foodstuff that is nutritionally balanced, affordable and used daily in the household. The egg can be enriched with various nutricines by designing mixtures for laying hens. Therefore, the aim of this study was to produce eggs enriched in selenium at two levels, lower and higher, and to examine its effect on egg quality and freshness indicators during storage in a refrigerator at 4 °C. Physicochemical properties of eggs and TBARS values, as indicators of oxidative processes, were investigated. 120 laying hens of Tetra SL hybrids were used in the research. The experiment lasted 5 weeks. At the beginning of the experiment, the laying hens were 30 weeks old. Two groups of hens, E1 and E2 were formed, which were fed with two mixtures. Each group was housed in 6 cages with 10 laying hens. The feed mixtures fed to the laying hens differed in the content of organic selenium (Sel-Plex). Feed for laying hens from E1 group contained lower levels of selenium (0.348 mg/kg), and laying hens from E2 group consumed feed with 0.447 mg Se/kg of the mixture. At the end of the experimental period, a total of 120 eggs were collected (E1 60 eggs and E2 60 eggs). Eggs belonged to class L (egg weight of 63-73 g). The analysis of the results did not reveal significant differences between the examined groups in the eggshell strength and thickness, weight of eggs and share of basic parts in the egg (P>0.05). Selenium levels in feed and time of analysis influenced the increase in pH in egg yolk and albumen (P<0.001). The time of analysis significantly influenced the reduction of albumen height (mm) and HU (P<0.001) while the color intensity was influenced by the time of analysis and interaction (P˂0.05). Lipid oxidation in egg yolks of the examined groups was uniform, no statistically significant differences in the obtained values were found (P>0.05). The level of selenium in feed mixtures for laying hens significantly affected its content in egg albumens and yolks. In albumen, the selenium content increased from 107.86 to 162.48 μg/kg (E1 compared to E2 ; P<0.001) and in yolk from 644.11 to 748.05 μg/kg (E1 compared to E2 ; P=0.032). The research established the possibility of increasing the selenium content in eggs by using the organic form of selenium in the feed mixture for laying hens. It was also observed that higher levels of selenium in feed have a positive effect on indicators of egg quality and freshness.

selenium ; eggs ; physical properties ; lipid oxidation

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