Surface properties of Ascaris suum eggs: hydrophobic potential and Lewis acid–base interactions

The cell surface properties of Ascaris suum eggs were investigated to determine the hydrophobic properties of eggs of different origins. Hydrophobic potential measurements were based on adhesion to hydrocarbons. Freshly laid eggs with or without the external coat and eggs that had been stored for 3 months at −20°C were tested. The hydrophobic potential differed according to the hydrocarbon used (hexadecane or octane) and the eggs tested (stored or fresh). The hydrophobic potential with octane was 95% for fresh eggs and 72% for eggs stored at −20°C. Tests with Ascaris eggs with and without an external coat showed similar hydrophobic characteristics; the presence or absence of this external structure did not appear to influence hydrophobic interactions. Acidic interactions also appeared to play no part in the adhesion of eggs to the surface of octane emulsions.