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Research article

Vol 2 No 1 (2008): Volume 2, Number 1, 2008

Pengaruh konsentrasi dan jenis larutan perendaman terhadap kecepatan ekstraksi dan sifat gel agar-agar dari rumput laut Gracilaria verrucosa

DOI
https://doi.org/10.22146/jrekpros.549
Submitted
November 11, 2023
Published
June 30, 2008

Abstract

Seaweeds of Gracilaria species are abundantly cultivated in Indonesia. However, studies related to its extraction
process are still rare. In the present work, the mass transfer process on a batch extraction of agar was studied by
extracting seaweeds in hot water solvent. The effect of alkali (NaOH) and acetic acid (CH3COOH) in the soaking
process on the volumetric mass transfer coefficient (kca) and the quality of gel agar were investigated.
Seaweeds (Gracilaria verrucosa) from Pekalongan coast were soaked in aqueous NaOH (1.5 N and 3.75 N) or in
aqueous acetic acid solution (0.2 N, 0.6 N, and 0.8 N). After being washed, the seaweeds were extracted in hot
water of 980C and neutral pH. Some of the extract samples at various times were freezed, thawed, dried and
weighed. The evaluation of experimental data showed that the mass transfer coefficient kca decreased and the gel
strength of agar increased with the increase of alkali concentration. Meanwhile, the value of kca increased and
the gel strength of agar decreased with the increase of acetic acid concentration.

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