Abstract
Carrageenan is used in a wide range of industries, especially in the food
industry, where their gelling qualities and viscointensifying properties
are greatly valued. Molecular characteristics and structural properties of
carrageenans extracted from the two seaweeds (Rhodophyta), Kappaphycus
alvarezii collected in Indonesia and Solieria pacifica
collected in Japan were investigated. Carrageenans were isolated and the
resulting extracts were recovered by precipitation with isopropyl alcohol.
Carrageenans from K. alvarezii and S. pacifica
were identified as kappa- and iota-carrageenan, respectively, by use of
Fourier transform infrared spectroscopy (FT-IR). Carrageenan from S.
pacifica provided no gel by cooling, while that from K. alvarezii
made gel upon cooling. The weight average molecular weights determined by
gel permeation chromatography (GPC) of carrageenans from K. alvarezii
and S. pacifica were 6.6×105 and 1.9×105,
respectively. Intrinsic viscosity, [η], of carrageenan
from K. alvarezii was 5.1 dl/g, while that from S.
pacifica was 5.5 dl/g. From these parameters, the carrageenan
extracted from K. alvarezii collected in Indonesia has
high potentiality for a commercial product because of high gelation
ability and molecular weight. While, carrageenan from S. pacifica
collected in Japan needs improvement of the extraction procedure to obtain
a gel-formable one.
