Abstract
This study focused on optimizing the extraction of carrageenan from two species of red macroalgae, false Irish moss (Mastocarpus stellatus (Stackhouse) Guiry) and Irish moss (Chondrus crispus Stackhouse), using subcritical water extraction (SWE). A central composite factorial design was used to assess the impact of temperature (90-160 ºC) and pressure (40-90 bar) on carrageenan yield (%) and gelling capacity. The extraction time and solid-to-liquid ratio were kept constant at 30 minutes and 1:30 g/mL (w/v), respectively. Thirteen different SWE conditions were tested for each macroalgae species. The resulting extracts were compared to those obtained through conventional extraction, which involved treatment with water for 3 hours at 80 ºC followed by 1 hour at 90 ºC. All hybrid carrageenan extracts were analyzed for molecular mass distribution, chemical composition, and gelling capacity in 0.1 M KCl. Carrageenan yields from M. stellatus varied between 51% (at 125 ºC/65 bar) and 74% (at 100 ºC/90 bar), while for C. crispus, yields ranged from 26% (at 100 ºC/90 bar) to 68% (at 140 ºC/40 bar). SWE had different impact on the characteristics of hybrid carrageenans isolated from C. crispus or M. stellatus. For the latter, both high pressure and temperature are detrimental to the content in iota-carrageenan in the hybrid, or even to the extraction of carrageenan. As a result, less M. stellatus extracts could actually gel in the presence of KCl. Overall, high temperature is a more limiting parameter than pressure as it directly leads to the extraction of shorter carrageenans. Smaller chain, of the order of 100 kDa were achieved at highest temperatures, whereas both seaweeds gave hybrid carrageenans of the order of 700 to 500 kDa. In general, extraction parameters did not notably impact the distribution of molecular masses, and C. crispus is more resistant to SWE.
Original language | English |
---|---|
Title of host publication | Libro de resúmenes del XXVIII Encontro Internacional Galego‐Portugués de Química |
Editors | Manuel Rodríguez Méndez, Fabiola Ramírez Gradilla |
Place of Publication | Santiago de Compostela |
Publisher | Colegio Oficial de Químicos de Galicia |
Pages | 338-338 |
Number of pages | 1 |
ISBN (Print) | 9788409664399 |
Publication status | Published - Nov 2024 |
Externally published | Yes |
Event | XXVIII Encontro Galego-Portugués de Química - Vigo, Spain Duration: 13 Nov 2024 → 15 Nov 2024 |
Conference
Conference | XXVIII Encontro Galego-Portugués de Química |
---|---|
Country/Territory | Spain |
City | Vigo |
Period | 13/11/24 → 15/11/24 |