Abstract:
Gracilaria verrucosa and Gracilaria edulis, economically valuable red algae species,
present in the coastal line of Sri Lanka in the Trincomalee, Kalpitiya and Puttalam
lagoon.
Utilization of seaweed is poor in Sri Lanka except a small amount is exported as
dried seaweed. It may be a good source for agar production, which is not studied so
far in Sri Lanka. Therefore the present study was carried out to extract gel (agar)
from Gracilaria species and to analyze the quality characteristics of gel. Preparation
of a value added product Geliy) from Gracilaria species was also aimed in the present
study.
For the extraction of gel, different concentrations of citric acid were used and the
most preferable level of citric acid percentage was determined by using statistical
application. Chemical analysis was done to determine the moisture, dry matter, crude
protein, crude fiber and total ash of the agar powder. Also the most preferable levels
of citric acid percentage for jelly were selected by sensory evaluation using hedonic
scale.
The most suitable citric acid percentage for the gel extraction was 0.1%. Chemical
analysis indicated that the jelly powder contains 15.78% moisture, 1.16% of crude
protein, 0.93% of crude fiber, 4.28% of total ash and 84.21% of dry matter. Gracilaria
seaweed jelly was prepared as a vegetarian dessert which contains 0.1% citric acidand
20% sugar. The melting temperature of the agar containing when 0.05% and
0.1% citric acid 40°C and 38°C also gelling temperature 92°C and 88°C respectively.
Further studies should be carried out for the shelf life evaluation and to study the
possibility of incorporating this agar powder in microbiological applications.
