Nutritional quality of some wild and cultivated seaweeds: Nutrient composition, total phenolic content and in vitro digestibility

• Published in: Journal of applied phycology Vol. 28; no. 6; pp. 3575 - 3585
• Main Authors: Tibbetts, Sean M., Milley, Joyce E., Lall, Santosh P.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2016; Springer Nature B.V
• Subjects: Alaria esculenta; Algae; Amino acids; Ascophyllum nodosum; Biomedical and Life Sciences; Chondrus crispus; Ecology; Freshwater & Marine Ecology; Fucus vesiculosus; Life Sciences; Magnesium; Manganese; Meristotheca papulosa; Nutrient content; Nutritive value; Palmaria palmata; Phenols; Plant Physiology; Plant Sciences; Saccharina latissima; Sarcodiotheca gaudichaudii; Trace elements; In vitro digestibility; Total phenolic content; Amino acids; Composition; Minerals; Seaweeds
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-016-0863-y

Nutrient composition, total phenolic content (TPC) and in vitro protein digestibility (IVPD) of wild and cultivated seaweeds were determined. Seaweeds had a high range of protein (7–31 % of dry weight (DW)), lipid (3–13 % DW), carbohydrate (32–60 % DW), ash (9–45 % DW) and energy (10–18 MJ kg
−1
DW). Seaweeds had favourable amino acid (AA) profiles with moderate (0.77–0.86) to high (0.93–1.07) essential AA indices. Major minerals and trace elements included calcium (0.1–1.1 % DW), magnesium (0.2–0.8 % DW), phosphorous (0.1–0.6 % DW), potassium (2.1–4.6 % DW), sodium (1.1–3.9 % DW), sulphur (0.4–6.5 % DW), copper (1–21 mg kg
−1
DW), iron (26–945 mg kg
−1
DW), manganese (3–191 mg kg
−1
DW) and zinc (28–74 mg kg
−1
DW). Red seaweeds contained low TPC (4–5 mg gallic acid equivalents (GAE) g
−1
DW) whereas most brown seaweeds contained moderate (11–18 mg GAE g
−1
DW) to high levels (47–59 mg GAE g
−1
DW). IVPD was mid-range (82–87 %) for
Saccharina latissima
,
Palmaria palmata
(W),
Palmaria palmata
(M-S),
Chondrus crispus
,
Meristotheca papulosa
and
Sarcodiotheca gaudichaudii
and lower (79 %) for
Ascophyllum nodosum
,
Fucus vesiculosus
and
Alaria esculenta
. Despite relatively good AA profiles, estimated digestible protein (DP) levels for seaweeds were generally low (<15 % DW) with exception of moderate levels (16–24 % DW) for
P. palmata
(W),
P. palmata
(M-S) and
S. gaudichaudii
. A highly significant inverse correlation (
r
 = −0.81,
R
2
 = 0.83,
P
 < 0.001) was found between TPC and IVPD of seaweeds (IVPD = 89.198 × TPC
−0.035
). The following species-specific nitrogen-to-protein conversion factors were determined:
P. palmata
(W), 6.28;
P. palmata
(M-S), 4.54;
C. crispus
, 4.85;
S. gaudichaudii
, 5.55.