The seasonal variation in nitrogen, amino acid, protein and nitrogen-to-protein conversion factors of commercially cultivated Faroese Saccharina latissima

Urd Grandorf Bak, Cecilie Wirenfeldt Nielsen, Gonçalo Silva Marinho, Ólavur Gregersen, Rósa Jónsdóttir, Susan Løvstad Holdt*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The demands of new food sources are increasing with the increasing human population. Proteins are a main nutrient for human consumption and in animal feed, which will be in short supply in the near future. Many macroalgal species have shown to possess significant levels and quality of protein, comparable to conventional protein-rich foods. The brown macroalga Saccharina latissima was commercially cultivated in an open ocean area in the Faroe Islands. The effect of depth, cultivation site and seasonal variation in nitrogen, protein concentration, and the amino acid profile were investigated to study the potential of Faroese cultivated S. latissima as a protein source. Moreover, the nitrogen-to-protein conversion factor was calculated. The average nitrogen concentration was 2.1 ± 0.2% of dry weight (dw) with no significant variation between sites, a single month with significant variation between cultivation depths (March 2016), and a significant seasonal variation (among most months). The average protein concentration determined by summing up total amino acids was 4.3 ± 0.9% of dw, and comparable to or slightly lower than other studies. There was no depth, site or seasonal variation in AA-protein concentration for the cultivated S. latissima. The lack of seasonal variation was most likely a consequence of the year-round stable physical conditions in the Faroe Islands, and compared with other studies surprising as most found seasonal variation of AA-protein. The quality of the protein was high (EAA score > 100%) in March, although the low total concentration of protein limits the possibilities to use S. latissima solely as a protein source or for protein extraction and other nutrients should be investigated to understand its potential as a food or feed source. This study will recommend estimating total protein concentration by summing up the total amino acids (AA-protein), as the widely used 6.25 factor is highly overestimating the protein concentration.

Original languageEnglish
Article number101576
JournalAlgal Research
Volume42
ISSN2211-9264
DOIs
Publication statusPublished - 2019

Keywords

  • Biochemical composition
  • Feed
  • Food
  • Kelp
  • Offshore
  • Seasonality

Cite this

@article{aed133a7f2034cdaa8c5e1eb82bc1ad9,
title = "The seasonal variation in nitrogen, amino acid, protein and nitrogen-to-protein conversion factors of commercially cultivated Faroese Saccharina latissima",
abstract = "The demands of new food sources are increasing with the increasing human population. Proteins are a main nutrient for human consumption and in animal feed, which will be in short supply in the near future. Many macroalgal species have shown to possess significant levels and quality of protein, comparable to conventional protein-rich foods. The brown macroalga Saccharina latissima was commercially cultivated in an open ocean area in the Faroe Islands. The effect of depth, cultivation site and seasonal variation in nitrogen, protein concentration, and the amino acid profile were investigated to study the potential of Faroese cultivated S. latissima as a protein source. Moreover, the nitrogen-to-protein conversion factor was calculated. The average nitrogen concentration was 2.1 ± 0.2{\%} of dry weight (dw) with no significant variation between sites, a single month with significant variation between cultivation depths (March 2016), and a significant seasonal variation (among most months). The average protein concentration determined by summing up total amino acids was 4.3 ± 0.9{\%} of dw, and comparable to or slightly lower than other studies. There was no depth, site or seasonal variation in AA-protein concentration for the cultivated S. latissima. The lack of seasonal variation was most likely a consequence of the year-round stable physical conditions in the Faroe Islands, and compared with other studies surprising as most found seasonal variation of AA-protein. The quality of the protein was high (EAA score > 100{\%}) in March, although the low total concentration of protein limits the possibilities to use S. latissima solely as a protein source or for protein extraction and other nutrients should be investigated to understand its potential as a food or feed source. This study will recommend estimating total protein concentration by summing up the total amino acids (AA-protein), as the widely used 6.25 factor is highly overestimating the protein concentration.",
keywords = "Biochemical composition, Feed, Food, Kelp, Offshore, Seasonality",
author = "Bak, {Urd Grandorf} and Nielsen, {Cecilie Wirenfeldt} and Marinho, {Gon{\cc}alo Silva} and {\'O}lavur Gregersen and R{\'o}sa J{\'o}nsd{\'o}ttir and Holdt, {Susan L{\o}vstad}",
year = "2019",
doi = "10.1016/j.algal.2019.101576",
language = "English",
volume = "42",
journal = "Algal Research",
issn = "2211-9264",
publisher = "Elsevier",

}

The seasonal variation in nitrogen, amino acid, protein and nitrogen-to-protein conversion factors of commercially cultivated Faroese Saccharina latissima. / Bak, Urd Grandorf; Nielsen, Cecilie Wirenfeldt; Marinho, Gonçalo Silva; Gregersen, Ólavur; Jónsdóttir, Rósa; Holdt, Susan Løvstad.

In: Algal Research, Vol. 42, 101576, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - The seasonal variation in nitrogen, amino acid, protein and nitrogen-to-protein conversion factors of commercially cultivated Faroese Saccharina latissima

AU - Bak, Urd Grandorf

AU - Nielsen, Cecilie Wirenfeldt

AU - Marinho, Gonçalo Silva

AU - Gregersen, Ólavur

AU - Jónsdóttir, Rósa

AU - Holdt, Susan Løvstad

PY - 2019

Y1 - 2019

N2 - The demands of new food sources are increasing with the increasing human population. Proteins are a main nutrient for human consumption and in animal feed, which will be in short supply in the near future. Many macroalgal species have shown to possess significant levels and quality of protein, comparable to conventional protein-rich foods. The brown macroalga Saccharina latissima was commercially cultivated in an open ocean area in the Faroe Islands. The effect of depth, cultivation site and seasonal variation in nitrogen, protein concentration, and the amino acid profile were investigated to study the potential of Faroese cultivated S. latissima as a protein source. Moreover, the nitrogen-to-protein conversion factor was calculated. The average nitrogen concentration was 2.1 ± 0.2% of dry weight (dw) with no significant variation between sites, a single month with significant variation between cultivation depths (March 2016), and a significant seasonal variation (among most months). The average protein concentration determined by summing up total amino acids was 4.3 ± 0.9% of dw, and comparable to or slightly lower than other studies. There was no depth, site or seasonal variation in AA-protein concentration for the cultivated S. latissima. The lack of seasonal variation was most likely a consequence of the year-round stable physical conditions in the Faroe Islands, and compared with other studies surprising as most found seasonal variation of AA-protein. The quality of the protein was high (EAA score > 100%) in March, although the low total concentration of protein limits the possibilities to use S. latissima solely as a protein source or for protein extraction and other nutrients should be investigated to understand its potential as a food or feed source. This study will recommend estimating total protein concentration by summing up the total amino acids (AA-protein), as the widely used 6.25 factor is highly overestimating the protein concentration.

AB - The demands of new food sources are increasing with the increasing human population. Proteins are a main nutrient for human consumption and in animal feed, which will be in short supply in the near future. Many macroalgal species have shown to possess significant levels and quality of protein, comparable to conventional protein-rich foods. The brown macroalga Saccharina latissima was commercially cultivated in an open ocean area in the Faroe Islands. The effect of depth, cultivation site and seasonal variation in nitrogen, protein concentration, and the amino acid profile were investigated to study the potential of Faroese cultivated S. latissima as a protein source. Moreover, the nitrogen-to-protein conversion factor was calculated. The average nitrogen concentration was 2.1 ± 0.2% of dry weight (dw) with no significant variation between sites, a single month with significant variation between cultivation depths (March 2016), and a significant seasonal variation (among most months). The average protein concentration determined by summing up total amino acids was 4.3 ± 0.9% of dw, and comparable to or slightly lower than other studies. There was no depth, site or seasonal variation in AA-protein concentration for the cultivated S. latissima. The lack of seasonal variation was most likely a consequence of the year-round stable physical conditions in the Faroe Islands, and compared with other studies surprising as most found seasonal variation of AA-protein. The quality of the protein was high (EAA score > 100%) in March, although the low total concentration of protein limits the possibilities to use S. latissima solely as a protein source or for protein extraction and other nutrients should be investigated to understand its potential as a food or feed source. This study will recommend estimating total protein concentration by summing up the total amino acids (AA-protein), as the widely used 6.25 factor is highly overestimating the protein concentration.

KW - Biochemical composition

KW - Feed

KW - Food

KW - Kelp

KW - Offshore

KW - Seasonality

U2 - 10.1016/j.algal.2019.101576

DO - 10.1016/j.algal.2019.101576

M3 - Journal article

VL - 42

JO - Algal Research

JF - Algal Research

SN - 2211-9264

M1 - 101576

ER -