PHYSICAL AND CHEMICAL-PROPERTIES OF AGAR FROM A NEW MEMBER OF GRACILARIA, G-LEMANEIFORMIS (GRACILARIALES, RHODOPHYTA) IN JAPAN

Agars of Gracilaria lemaneiformis, a new member of Gracilaria in Japan , were extracted by the alkali treatment method with various concentra tions of NaOH (1, 3, 5, 7, 9%) at 80 degrees C. The treated samples we re incubated for 1, 2, and 3 hours. Agar gel strength, gel deformation , and apparent Young's modulus were measured, and showed excellent gel characteristics. The highest gel strength of 1706.8 +/- 164.0 g/cm(2) was obtained from 1% agar of 3% NaOH, 3 h treatment, with gel deforma tion of 9.9 +/- 0.9 mm, and apparent Young's modulus of 171.7 +/- 1.1 g/mm, compared with the other treatments in this study. Agar solutions of this seaweed could form a firm gel at the very low concentration o f 0.5% agar. Sulfate and 3,6-anhydro-L-galactose contents reached the highest value of 4.4% from non-alkali treated agar, and 48.1% from 3% NaOH, 3 h treated agar, respectively. The methoxyl contents attained t he highest value (1%) in non-alkali treated agar and 1% NaOH, Ih treat ed agar. The agar of G. lemaneiformis showed an essentially higher gel strength compared with the Japanese commercial grade agars.