The extraction of carrageenan and its effect on the gel texture

Summary Carrageenan was extracted from Eucheuma cottonii under various conditions of temperature, alkalinity and time. The effect of process parameters on the rheological properties of the resulting carrageenan gels was studied. Raising the extraction temperature from 100 to 110°C under alkaline conditions increased the 3,6‐anhydrogalactose content, and extending the period of extraction up to 3 hr yielded gels with a higher gel strength and deformability modulus. Carrageenan gels were evaluated by compression on a Universal testing machine linked to a microcomputer system. This enabled continuous accumulation and processing of the force‐deformation data. The computerized method for texture analysis, presented in this study, enables rapid and accurate assessment of the gelling properties of crude carrageenans and of mixtures with other additives.