Abstract:
Agar, a natural biopolymer extracted from red algae, holds immense potential for
revolutionizing healthcare, including biomedical engineering. This study explores the
extraction feasibility of agar from red algae (Gracilaria tenuistipitata) abundantly
available in the coastal area of Cox’s Bazar, Bangladesh. Five extraction methods
were investigated, including a control group and treatments with water and NaOH
solutions at concentrations of 2%, 4%, and 6%. The extraction of agar from algae
was characterized through Fourier-transform infrared spectroscopy (FTIR), gel
strength testing, melting and gelling temperature assessments, pH value
measurement, and sulfate content analysis. Statistical analysis, including ANOVA
and Tukey's HSD test, was utilized to assess the impact of the pre-treatment process
on the yield and characteristics of agar. The test revealed significant variations
among the different extraction methods (p < 0.05), highlighting the crucial role that
pre-treatment plays in influencing agar yield and its physicochemical properties.
While the control group achieved the highest agar yield (16.67 ± 1.44%), the 2%
NaOH pre-treatment showed superior physicochemical attributes. Specifically, this
treatment resulted in agar with optimal gel strength (3.25 ± 0.67 N/cm²), melting
temperature (84.20 ± 0.80°C), gelling temperature (36.13 ± 1.21°C), pH (7.49 ±
0.26), and sulfate content (3.67 ± 0.58 mg/L), all of which are comparable to those of
commercial agar. This preliminary study suggests that the red algae (Gracilaria
tenuistipitata) found in Bangladesh is a promising source of agar for wider
applications, including biomedical engineering. The agar extracted from abundant
local sources in this country could unlock its potential for advancing healthcare
solutions and sustainable national economic growth.
