Comparison of cystatin, lysozyme and Anti-trypsin agents activities in geese egg white

The objective of the study was to examine the activity of different biologically active proteins in geese egg whites. The experiment was performed in 8 replicates on eggs collected from Italian White geese, Polish wild geese (Gegawa) and their cross line. Analyses of activities of cystatin, lysozyme and serine proteinases inhibitors in fresh geese egg whites were carried out. Moreover, trypsin activity of egg white inhibitors was checked after 30 days of storage. Statistical analysis of the results showed that Gegawa geese egg whites were characterized by the highest anti-trypsin activity (416.2 u/mg protein), whereas eggs collected from Italian white line expressed the lowest biological activities of ovomucoid and ovoinhibitor. Storage of eggs in chill room for 30 days decreased the activity of antitrypsin components of egg whites, especially for Gegawa geese. Significant loss of total protein content in egg white was also observed at the end of the storage time for all analyzed geese lines. The highest decreases in total protein content in egg white from 107 mg/cm for fresh eggs to 95 mg/cm for stored eggs was noticed for cross line. Cystatin activity measured in egg white collected from geese lines Italian White and Gegawa were formed on the same level and it amounted to 7.4 u/mg protein. Activity of lysozyme was higher in eggs obtained from Italian White geese than from Gegawa geese. Higher activities of biologically active proteins naturally occurring in geese eggs were observed in fresh egg white than in stored eggs. Eggs collected from Italian White geese were characterized by the highest activity of lysozyme, whilst trypsin inhibitors present in those eggs were less active. Unlike Italian White geese, Gegawa geese produced eggs with high activity of ovomucoid and ovoinhibitor, whereas lysozyme was far less active.