New gelling properties of Alaska pollack frozen mince induced by urea.

Abstract

A mixture of finely chopped Alaska pollack frozen mince (100g) and 8M urea (300ml) was heated until it dissolved. The solution was dialyzed against 10l of water, first at 4°C overnight and next at 60°C for several hours. The dialyzate (urea-treated mince, water content 95-97%) was a grayish, semi-transparent liquid at room temperature, but set to a brittle gel on cooling. The molten, urea-treated mince was poured into a glass tube and frozen into a suitable shape at -20°C. By immersing the shaped frozen mince in CaCl2, CaSO4, MgCl2 or MgSO4 (0.1-1.0M), or in CH3COOH-NaOH or HCl-NH4OH (pH 4-5), an elastic, whitish gel (water content 80-97%) was obtained. If the molten, urea-treated mince was injected into these solutions with a syringe, a noodle-like, long and slender gel was formed. If the mince was poured into a hot salt solution and the resulting suspension was wrung with a thick cloth, the residue coagulated on cooling in the wrung from. The gels formed by the reaction with salt or buffer did not melt on heating. The elasticity of the flesh gel, Kamaboko, from Alaska pollack frozen mince was not improved by the addition of the urea-treated mince.