TY - JOUR
T1 - Production and characterization of protein-rich extracts from the red macroalga Gelidium corneum and its industrial agar extraction residues
AU - Mateus, Marília
AU - Mão de Ferro, Rita
AU - Pinheiro, Helena M.
AU - Machado, Remígio
AU - da Fonseca, M. Manuela R.
AU - Sapatinha, Maria
AU - Pires, Carla
AU - Marmelo, Isa
AU - Marques, António
AU - Nunes, Maria Leonor
AU - Motta, Carla
AU - Cesário, M. Teresa
N1 - Funding Information:
The research leading to these results has received funding from Fundo Azul - DGPM , project FA-05-2017-033 . Financial support was also received by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the project UIDB/04565/2020 and UIDP/04565/2020 and of the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy - i4HB . IM also acknowledges FCT I.P. for PhD grant ( 2020.04413.BD ).
Publisher Copyright:
© 2024 The Authors
PY - 2024/3
Y1 - 2024/3
N2 - The red macroalga Gelidium corneum is a species commercially exploited for agar extraction, though with enormous potential for other industrial applications. This work aimed to produce protein-rich extracts from the crude alga and from residues of the industrial agar extraction process by applying different extraction and recovery procedures, and to characterize the obtained protein extracts. The sequential implementation of two water extractions followed by two alkaline extractions resulted in the recovery of 12.0 ± 1.2 % and 15.4 ± 0.9 % of the total protein contents of the crude alga and industrial residues, respectively. Two sequential water extractions assisted by Celluclast® and Alcalase® enzymes followed by two alkaline extractions recovered 52.1 ± 1.7 % and 36.5 ± 1.3 % of the protein contents of the crude alga and industrial residues, respectively. Extracts produced by these processes were characterized focusing on proximal composition, protein accessibility, nutrition and antioxidant potential, showing value as aquaculture feed ingredients. As all protein products revealed high carbohydrate contents and, aiming at enriching protein content, different protein precipitation methods were assessed, namely through ammonium sulfate precipitation and pH-shift protocols. The pH-shift method in sequential mode proved to be simple and fast with low reagent consumption. The purification of extracts by this precipitation mode allowed precipitating up to 72 % of the extracted protein. The results obtained suggest that protein concentrates extracted from Gelidium corneum appear to be promising sustainable sources for fish feed production, owing to their essential amino acid content, protein bioaccessibility and antioxidant properties.
AB - The red macroalga Gelidium corneum is a species commercially exploited for agar extraction, though with enormous potential for other industrial applications. This work aimed to produce protein-rich extracts from the crude alga and from residues of the industrial agar extraction process by applying different extraction and recovery procedures, and to characterize the obtained protein extracts. The sequential implementation of two water extractions followed by two alkaline extractions resulted in the recovery of 12.0 ± 1.2 % and 15.4 ± 0.9 % of the total protein contents of the crude alga and industrial residues, respectively. Two sequential water extractions assisted by Celluclast® and Alcalase® enzymes followed by two alkaline extractions recovered 52.1 ± 1.7 % and 36.5 ± 1.3 % of the protein contents of the crude alga and industrial residues, respectively. Extracts produced by these processes were characterized focusing on proximal composition, protein accessibility, nutrition and antioxidant potential, showing value as aquaculture feed ingredients. As all protein products revealed high carbohydrate contents and, aiming at enriching protein content, different protein precipitation methods were assessed, namely through ammonium sulfate precipitation and pH-shift protocols. The pH-shift method in sequential mode proved to be simple and fast with low reagent consumption. The purification of extracts by this precipitation mode allowed precipitating up to 72 % of the extracted protein. The results obtained suggest that protein concentrates extracted from Gelidium corneum appear to be promising sustainable sources for fish feed production, owing to their essential amino acid content, protein bioaccessibility and antioxidant properties.
KW - Agar extraction residue
KW - Aquaculture feed
KW - Gelidium corneum
KW - Protein extraction
KW - Protein extracts characterization
KW - Protein precipitation
UR - http://www.scopus.com/inward/record.url?scp=85185450968&partnerID=8YFLogxK
U2 - 10.1016/j.algal.2024.103420
DO - 10.1016/j.algal.2024.103420
M3 - Article
AN - SCOPUS:85185450968
SN - 2211-9264
VL - 78
JO - Algal Research
JF - Algal Research
M1 - 103420
ER -